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Copepod-chondrichthyan coevolution : a cladistic consideration Deets, Gregory B. 1995

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COPEPOD-CHONDRICHTHYAN COEVOLUTION:A CLADISTIC CONSIDERATIONGREGORY B. DEETSB.Sc., California State University Long Beach,M.Sc., California State University Long Beach,19801985A THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFDOCTOR OF PHILOSOPHYWe accept this thesis as conformingto the required standardbyinTHE FACULTY OF GRADUATE STUDIESDepartment of ZoologyTHE UNIVERSITY OF BRITISH COLUMBIAAUGUST 1994©Gregory B. Deets, 1994In presenting this thesis in partial fulfilment of the requirements for an advanceddegree at the University of British Columbia, I agree that the Library shall make itfreely available for reference and study. I further agree that permission for extensivecopying of this thesis for scholarly purposes may be granted by the head of mydepartment or by his or her representatives. It is understood that copying orpublication of this thesis for financial gain shall not be allowed without my writtenpermission.(Signature)_____________________________Department of___________________The University of British ColumbiaVancouver, CanadaDate_______ _ _ _DE.6 (2/88)ABSTPCTA revision of the species of Eudactylina (Eudactylinidae : Siphonostomatoida)and Kroyeria (Kroyeriidae : Siphonostomatoida) was conducted, based on type andother specimens of parasitic copepods from museums and personal collections. Adescription of the external morphology of each genus is included. Taxonomic, phylogenetic, and functional significance of the morphology of the general habitus, first andsecond antennae, oral and thoracic appendages are discussed.The taxonomic account of the above genera recognized all nominal species inthe literature. Illustrations and phylogenetic analyses, however, were necessarilyrestricted to only the material examined in an attempt to standardize the abstractionsand interpretations associated with character observation. Detailed redescriptions aregiven of E. acuta, E. aspera, E. chilensis, E. corrugata, E. indivisa, E. insolens, E.Iongispina, E. myliobatidos, E. oliveri, E papillosa, E. peruensis, E. pollex, E. pusilla,E. similis, E. spinifera, E. squamosa, E tuberifera, E. turgipes, and new descriptions(all in press) are given of, E. aphiloxenous, E. dactylocerca, E. diabolophila, E. epaktoIampte’ E. hornbosteli, E. nykterimyzon, E. pristiophori, E. urolophi, and E. vaquetillaefollowed by the detailed reclescriptions of K. carchariaeglauci, K. caseyi, K. dispat K.elongata, K. gemursa, K. lineata, K. longicauda, K. papillipes, K. spatulata, K. sphyrnae, K. triakos and new descriptions (all in press) of K. branchioecetes, Kcresseyi, K.decepta, K. procerobscena, and K. rhophemophaga.In an attempt to unravel evolutionary relationships of their elasmobranch hostsand themselves a phylogenetic analysis of each genus is presented. In the heuristicanalysis of Eudactyilna, 75 morphological characters resulted in a single tree with aconsisitency index of 0.77 and a retention index of 0.88, indicating a high degree ofcharacter congruence. An exact search of nine species of Eudactylina with 55 characters resulted in a single tree with a consistency index of 0.88 and a retention index of0.88. The Eudactylina-derived host cladograms posit monophyly of the shark-likesqualoids , squatinids, pristiophorids, and batoids. This suggests that shark-likesqualoids, angelsharks, and sawsharks are more closely related to rays than to othergaleomorph sharks, whereas the pristiophorids represent the sister taxon to batoids.The eudactylinid dade found on the rhinopterids and mobulids appears to represent acolonization event followed by tight cospeciation. Eudactylina-derived carcharhinidrelationships approximate conventional or currently accepted hypotheses. Eudactylinaderived phyogenetic relationships of a subset of species from Squatina and Myliobatisindicate speciation patterns consistent with major vicariant events associated with thebreakup of Pangaea during the Jurassic period approximately 160 MY.The phylogenetic analysis of Kroyeria, using 44 morphological characters resulted in a single tree with a consistency index of 0.75 and a retention index of 0.75. TheKroyeria-derived and Kroyeria-Kroeyerina-derived host cladograms posit an unconventional placement for Galeocerdo. Galeocerdo diverges at the bottom of the tree beforethe Triakidae. A sphyrnid dade follows, functioning as the sister taxon to remainingmembers of the Carcharhinidae. The genus Carcharhinus appears paraphyletic withNegaprion and Prionace imbedded within this dade, corroborating similarly held viewsby other systematists.Congruent host and parasite cladogram topologies from both holocephalan andelasmobranch hosts suggest the existence of well-established and specific host-parasite associations as early as the late Devonian, approximately 400 MY.IIITABLE OF CONTENTSAbstract.List of Tables ixList of Figures xAcknowledgements xiiiINTRODUCTION 1MATERIALS AND METHODS 12HISTORICAL REVIEW 15EUDACTYLINA 18EXTERNAL MORPHOLOGY 18GENERAL HABITUS 18CAUDALRAMUS 19FIRSTANTENNA 19SECOND ANTENNA 20ORAL CONE AND MANDIBLE 20FIRST MAXILLA 20SECOND MAXILLA 21MAXILLIPED 21LEG ONE 22LEG TWO 22LEGSTHREEANDFOUR 23LEG FIVE 23LIFE HISTORY 24GENERAL DESCRIPTION 24REPRODUCTION 25ivHOST-PARASITE RELATIONSHIPS 26DELETERIOUS EFFECTS! FEEDING 26SPECIFICITY 26SYSTEMATIC ACCOUNT 27GENUS EUDACTYLINA van Beneden, 1853 27Eudactylina acanthil A. Scott, 1901 28Eudactylina acuta van Beneden, 1853 30Eudactylina aphiloxenos sp. nov 33Eudactylina aspera HelIer, 1865 35Eudactylina chilensis Ho and McKinney, 1981 38Eudactylina corrugata Bere, 1930 40Eudactylina dactylocerca sp. nov 42Eudactylina diabolophila sp. nov 45Eudactylina dolifusi, Brian, 1924 47Eudactylina epaktolampter sp. nov 50Eudactylina hornbosteli sp. nov 54Eudactylina indivisa Castro and Baeza, 1991 56Eudactylina insolens Scott and Scott, 1913 58Eudactylina longispina Bere, 1936 60Eudactylina myliobatidos Luque and Farfan, 1991 62Eudactylina nykterimyzon sp. nov 65Eudactylina oliveri Laubier, 1968 68Eudactylinapapillosa Kabata, 1979 72Eudactylinaperuensis Luqueand Farfan, 1991 74Eudactylina pollex Cressey, 1967 76Eudactylinapristiophori sp. nov 79Eudactylina pus//Ia Cressey, 1967 81Eudactylina s/mills Scott, 1902 83vEudactylina squamosa Bere, 1936• 85Eudactylina tuberifera Castro and Baeza, 1987 88EudactylinaturgipesBere, 1936 90Eudactylina urolophi sp. nov 92Eudactylina vaquetillae sp. nov 95REMAINING UNOBTAINABLE NOMINAL SPECIES 97PHYLOGENETIC ANALYSIS 101CLADOGRAM CONSTRUCTION 101PARASITE-DERIVED HOST CLADOGRAM 102HISTORICAL BIOGEOGRAPHY 105KROYERIA 109EXTERNAL MORPHOLOGY 109GENERAL HABITUS 109CAUDAL RAMUS 110DORSAL AND INTERPODALSTYLETS 110FIRST ANTENNA 112SECOND ANTENNA 112MANDIBLE AND ORAL CONE 113FIRST MAXILLA 113SECOND MAXILLA 113MAXILLIPED 114LEG ONE 114LEGTWO 115LEG THREE 115LEG FOUR 116LEGSFIVEANDSIX 116LIFE HISTORY 117GENERAL DESCRIPTION 117viREPRODUCTION.117HOST-PARASITE RELATIONSHIPS 118DELETERIOUS EFFECTS! FEEDING 118SPECIFICITY 119SYSTEMATIC ACCOUNT 119GENUS KROYERIA van Beneden, 1853 119Kroyeria branchioecetes sp. nov 121Kroyeriacarchariaeglauci Hesse, 1879 123Kroyeria caseyl Benz and Deets, 1986 127Kroyeria cresseyl sp. nov 129Kroyeria decepta sp. nov 132Kroyeriadispar Wilson, 1932 135Kroyeriaelongata Pillai, 1967 138Kroyeria gemursa Cressey, 1967 140Kroyeria lineata van Beneden,1853 143Kroyeria longicauda Cressey, 1970 146Kroyeriapapillipes Wilson, 1932 149Kroyeriaprocerobscenasp. nov 151Kroyeria rhophemophaga sp. nov 154Kroyeriaspatulata Pearse, 1948 157Kroyeria sphyrnae Rang nekar, 1957 160KroyeriatriakosFukui, 1965 163REMAINING UNOBTAINABLE NOMINAL SPECIES 166PHYLOGENETIC ANALYSIS 168CLADOGRAM CONSTRUCTION 168PARASITE-DERIVED HOST CLADOG RAM 169COMBINING PARASITE CLADOGRAMS 170COMPETING HOST CLADOGRAMS 172viiSUMMARY AND CONCLUSIONS.176REFERENCES 178FIGURES 196APPENDICESAPPENDIX A -435DATA MATRIX AND DEFINITION OF CHARACTERSFOR EUDACTYLINA 436DATA MATRIX FOR EUDACTYLINA SUBSET 441DATA MATRIX AND DEFINITION OF CHARACTERSFOR KROYERIA 445APPENDIX B -APPENDIX C -v”List of TablesI. RECODED EUDACTYLINA PHYLOGENY BY HOST MATRIX 430II. RECODED EUDACTYLINA SUBSET PHYLOGENY BY HOST MATRIX. . .431III. RECODED KROYERIA PHYLOGENY BY HOST MATRIX 432IV. RECODED KRQEYERINA BY HOST MATRIX 433V. COMBINED RECODED KROYERIA-KROEYERINA BY HOST MATRIX. . . . 434ixList of Figures1. Eudactylina attached to gill filament in situ 1972-3 EudactylinaacanthiiA. Scott, 1901 1994-5. Eudactylina acuta van Beneden, 1853 2036-7. Eudactylina aphiloxenos sp. nov 2078-9. Eudactylina aspera HelTer, 1865 21110-11. Eudactylina chilensis Ho and McKinney, 1981 21512-13. Eudactylina corrugata Bere, 1930 21914-15. Eudactylina dactylocerca sp. nov 22316-17. Eudactylinadiaboiophiiasp. nov 22718-19. Eudactylina dolifusi, Brian, 1924 23120-23. Eudactylina epaktoiampter sp. nov 23524-25. Eudactylina hornbostelisp. nov 24326-27. Eudactylina mdivisa Castro and Baeza, 1991 24728-29. Eudactylina insolens Scott and Scott, 1913 25130-31. Eudactylina longispina Bere, 1936 25532-33. Eudactylina myliobatidos Luque and Farfan, 1991 25934-35. Eudactylina nykterimyzon sp. nov 26336-39. Eudactylina oilyen Laubier, 1968 26740-41. Eudactylina papillosa Kabata, 1979 27542-43. Eudactylinaperuensis Luqueand Farfan, 1991 27944-45. EudactylinapoliexCressey, 1967 28346-47. Eudactylina pristiophori sp. nov 28748-49. Eudactylina pusilla Cressey, 1967 29150-51. Eudactylina simiiis Scott, 1902 29552-53. Eudactylina squamosa Bere, 1936 29954-55. Eudactylina tuberifera Castro and Baeza, 1987 303x56-57. Eudactylina turgipes Bere,1936 30758-59. Eudactylina urolophisp.nov 31160-61. Eudactylina vaquetillae sp. nov 31562. Eudactylinidae Cladogram 31963. Eudactylinidae Host-Summary Cladogram 32164. Eudactylina Cladogram (Heuristic) 32365. Eudactylina Cladogram (Exact) 32566. Eudactylina-derived Host Cladogram (Heuristic) 32767. Eudactylina-derived Host Cladogram (Exact) 32968. Area-Summary Cladogram for Squat/na 33169. Area-Summary Cladogram for Myliobatis 33370. Kroyeria attached to gill filament (in situ) 33571-73. Kroyeria branchioecetes sp. nov 33774-76. Kroyeria carchariaeglauci Hesse, 1879 34377-78. Kroyeria caseyi Benz and Deets, 1986 34979-80. Kroyeria cressey/sp. nov 35381-84. Kroyeria decepta sp. nov 35785-86. KroyeriadisparWilson, 1932 36587-88. Kroyeria elongata Pillai, 1967 36989-90. Kroyeria gemursa Cressey, 1967 37391-92. Kroyeria lineata van Beneden, 1853 37793-95. Kroyeria longicauda Cressey, 1970 38196-97. Kroyeria papillipes Wilson, 1932 38798-99. Kroyeria procerobscenasp. nov 391100-102. Kroyeriarhophemaphaga sp. nov 395103-104. Kroyeria spatulata Pearse, 1948 401105-106. Kroyeria sphyrnae Rangnekar, 1957 405107-108. KroyeriatriakosFukui, 1965 409xi109. Kroyeriidae Cladogram 413110. KroyeriaCladogram 415111. Kroyeria-derived host cladogram 417112. Kroeyerina attached to olfactory lamellae (in situ) 419113. Kroeyerina-derived host cladogram 421114. Combined Kroyeria-Kroeyerina-derived host cladogram 423115. Competing cladogram of Squalea and Hypnosqualea 425116. Competing morphological and molecular cladograms of carcharhinids 427xiiAcknowledgementsThe completion of this dissertation was far from a single-handed effort. I thankmy graduate advisor and friend Dr. Martin Adamson for his guidance, friendship, criticalreview of the manuscript, humor, patience and especially his cheap home-made winefermented under his house. Thank you Dr. Kabata (committee member) for your friendship, specimens, and world renown professionalism and ability, standards I’ll nevermeet. And thank you to committee members Dr. Al Lewis and Dr. Geoff Scudder forkindly serving on my committee, offering ideas and advice and editing this monstrousthing.Additional thanks go to Dr. Ju-Shey Ho and Dr. Masahiro Dojiri for use of theirlibraries and insightful discussions.Dr. Roger Cressey deserves more than a species named after him! His help forthe arrangement of loans for these parasitic copepods from the National Museum ofNatural History, Smithsonian lnstitutuion, coupled with the donation of his vast personalcollection for my inspection resulted in the discovery of many new species and is largely responsible for the comprehensiveness of this effort. His sponsorship and kindnessduring my short-term appointment at the Smithsonian will never be forgotten.I appreciate the assistance of Dr. Geoffrey Boxshall, The Natural HistoryMuseum, London, England, and Dr. Frank Ferrari, National Museum of Natural History,Smithsonian Institution, for shipping additional parasitic copepods to me for this revision.I must thank George Benz for so many hilarious memories that again will neverbe forgotten, and who kept me going during some of the most testing and strenuoustimes in my life. His assistance on our co-authorships, his critical eye, insight andincredible potential for being such a S.O.B. is deeply appreciated.I thank Bernard Horn-Bostel (father-in-law equivalent) for financially assisting thisproject with a generous donation of a Mac II, allowing the phylogenetic analyses andword processing to be done.The wild uncontrollable spending by Patricia Horn-Bostel (mother-in-law-equivalent) on new software and hardware allowed many of the final figures to be completedas our hard drive was busting at the sectors.1 will be forever grateful to the Friends of the Provincial Museum, BritishColumbia for a generous award in Zoology and Museum Studies, literally keeping meafloat when everything else was sinking.XIIEMostly, I thank Deborah Allison Horn-Bostel (spousal-unit equivalent) for helpingwith the trivial, such as the computer figures, some of the in situ illustrations, and tolerating some absolutely hideous field conditions. But more importantly, I thank her foralways being there, objective and supportive in every episode of life while this wasbeing attempted.Finally, this is dedicated to the memory of my parents, Hubert and FlorenceDeets, both passing away during this long process.xiv(hen I was a boy, world was better spot.what was so was so,what was not was not.Now I am a manworld have changed a lotSome things nearly so, others nearly not.There are times I almost thinkI am not sure of what I absolutely know.Very often find confusion in conclusionI concluded long ago.In my head are many facts that as a studentI have studied to procure.In my head are many facts of whichI wish I was more certain I was sure.Oscar Hammerstein ItThe King & IA Puzzlement1956xvINTRODUCTIONCoevolution has become an increasingly popular sub-discipline within the field ofevolutionary biology. Ehrlich and Raven (1964) defined coevolution as an ecologicalphenomenon, a matter of “stepwise reciprocal response” between any two species with“close and evident” ecological relationships. Parasitologists citing von lhering (1891)have recognized a more restricted sense of coevolution; the historical relationshipsbetween hosts and parasites. Coevolution embodies two components, togetherness(co-) and history (evolution) (Mitter and Brooks, 1983). The study of togetherness (thefunctional fit of organisms to their environment) is usually restricted to the field of ecology. The study of history (phylogeny) is enveloped within the realm of systematics(Brooks, 1 985a). Although this historical component is missing from most of the earlierassessments of putatively coevolved systems (Brooks, 1 979a; Brooks and Mitter, 1984;Mitter and Brooks, 1983), recent efforts have attempted to incorporate it (Brooks andMcLennan, 1991,1993; Paterson, Gray & Wallis, 1993).Whether one studies free-living or parasitic organisms, the species associationsa given taxon exhibits are usually well defined, quite specific and brought about by acombination of descent and proximal or contemporaneous causes (colonization).Hence, it is of interest to determine whether most species associations are maintainedas equilibrium systems fueled by constant dispersal or maintained as historically constrained associations.Recent advances in systematics, among them the development of cladistics,allow one to approach the question from a phylogenetic standpoint. Specific questionsregarding coevolution, the evolution of ecological life-history traits, historical biogeography and classification can be addressed if an explicit phylogenetic hypothesis is available.Cladistics, or phylogenetic systematics, attempts to reconstruct genealogical1relationships among taxa by determining the sequence of the origin of their distinguishing features (Hennig, 1966; Wiley, 1981). The major interest in cladistics is centered onconstruction of branching sequences and defining monophyletic groupings or naturaltaxa. In practicing cladistics, phylogeneticists subscribe strictly to a structural, asopposed to a functional, approach to systematics. Observations of character structureare used to construct a hierarchical pattern of taxa, then from these patterns the validityof hypotheses concerning evolutionary mechanisms is scrutinized (Brooks and Wiley,1986). Therefore, cladistic analyses attempt to dissociate inferences of organismic relationships and evolutionary pattern from assumptions concerning process (Ho andSaunders, 1984). Indeed, one of the most important contributions of cladistics has beento focus attention on the vital importance of pattern analysis, for it is only by havingsome aspect of pattern that science has something to explain (Cracraft, 1983).Formal statements concerning modern cladistic methods were made by Hennig(1950, 1966). He proposed a general reference system for comparative biology basedon two major points. First he distinguished between special reference systems and general reference systems in biological classifications. Special reference systems emphasize a particular kind of relationship among different species. For example, a classification that placed all parasitic copepods inhabiting shark gills in one category, and allthose on batoid gills in another would be a special reference system useful for categorizing parasitic copepods in given host assemblages. This classificatory procedurewould place distantly related organisms in the same taxonomic category. A general reference system should provide the most efficient summary of the maximum amount ofinformation about the taxa being classified (Brooks, 1985b). Hennig suggested that thegeneral reference system in biology should be based on the genealogical or phylogenetic relationships of the species involved. The choice of genealogy was based on twoobservations: (1) the one attribute of any organism or species that would always beconstant was its history, so phylogenetic history should be the most stable criterion forclassifying and (2) genealogical relationships, like classifications, are inherently hierar2chical.Secondly, Hennig argued for a formal method of deducing phylogenetic relationships. He objected to phylogenetic schemes that were based on hypothetical idealizedarchetype ancestors. Since species are composites of ancestral and derived traits, it isunlikely such things as archetypes exist. Thus, homologous traits shared by two ormore species will be indicators of phylogenetic relationship. Shared primitive traits indicate general phylogenetic relationships while shared derived traits indicate more particular phylogenetic relationships. The terms plesiomorphy (plesio - near the source) andapomorphy (apo - away from the source) refer to these relatively primitive and relativelyderived traits. Two taxa that share derived homologous characters (synapornorphies)are each other’s closest relatives and are called sister taxa (Hennig, 1966).There are two comparative methods for evaluating the degree of primitiveness ofcharacters. These are the “ontogenetic criterion” and the “outgroup criterion”. Bothapproaches seek to establish the direction or path of transformation from the primitiveto a more derived character state. A primitive or plesiomorphic character is more general because it defines a group that is more inclusive than one defined by a less general,more derived or apomorphic condition of that character. Hence, the diagnostic featuresof each grouping in the genealogical hierarchy would be those traits viewed as apomorphic at that level of that particular grouping (Wiley, 1981).The outgroup criterion states that any trait found in at least one member of thegroup being studied that also occurs in taxa outside the study group is plesiomorphic.Since outgroups are not archetypes and, therefore, may possess derived characterstates, it is often necessary to use more than one outgroup (composite outgroup) toestablish enough apomorphic traits to classify a taxon (Maddison,et al., 1984).The ontogenetic criterion states that, where two organisms possess differentadult states, if one organism exhibits the other’s adult trait during development, its adulttrait is apomorphic and that of the other adult trait is plesiomorphic. This approach ismore limited than outgroup analysis, since it works only for cases in which evolution3has proceeded by adding characteristics to the ancestral developmental program(Brooks and Wiley, 1986).After determining which traits are apomorphic and which are plesiomorphic, oneis sometimes faced with apomorphic traits that suggest conflicting groupings. The reason for this is parallel and/or convergent evolution, given the general name homoplasy,where similarity causes one to misattribute homology. Truly homologous traits of various taxa will yield congruent groupings. As long as homoplasious traits do not co-varyin larger numbers than the homologous traits, parsimony analyses will pinpoint theproper phylogenetic relationships. The possible occurrence of great amounts of parallelevolution requires only that many traits be used in the analysis, since the pattern ofrelationships indicated by a plurality of traits is the best estimate of phylogenetic relationships (Brooks, 1985b). Since this requires that large numbers of traits be analyzedsimultaneously, phylogenetic computer packages such as PAUP (PhylogeneticAnalysis Using Parsimony) and MacClade have been developed to generate and analyze phylogenetic trees.As previously stated, concordance between phylogenetic relationships of parasites and their hosts has been recognized since the nineteenth century (von Ihering,1891). Hennig (1966) discussed the concordance briefly and the resultant possibility ofinferring host phylogenies from parasite data. The continued discovery of co-varyingassociations between parasites and their hosts has led to the formulation of various“rules” of coevolution. The rules form a small group of interrelated concepts:1. Eichler’s Rule (for review see, Inglis, 1971): The more genera of parasites ahost harbors, the larger the systematic group to which the host belongs.2. Manter’s Rules (for review see Inglis, 1971): (1) Parasites evolve more slowlythan their hosts; (2) the longer the association with a host group, the more pronouncedthe specificity exhibited by the parasite group; (3) a host species harbors the largestnumber of parasite species in the area where it has resided longest, so if the same ortwo closely related species of host exhibit a disjunct distribution and possess similar4parasite faunas, the areas in which the hosts occur must have been contiguous at apast time.3. Szidat’s Rule (see Szidat, 1956; 1960): The more primitive the host, the moreprimitive the parasite it harbors.Finally, and probably the best known:4. Farenholz’s Rule (for reviews see Brooks, 1979a, 1981, 1985a; Inglis, 1971):Parasite phylogeny mirrors host phylogeny.Brooks (1981) developed this latter concept of coevolution in terms of phylogenetic systematics (cladistics) and suggested that host-parasite coevolution can arisethrough processes comparable to those that produce homologous and homoplasiouscharacters. This analogous relationship between character state transformation seriesand parasite phylogenies allows one to view cospeciated or historically associated parasites as homologies or autapomorphies of their hosts and colonizing parasite speciesas homoplastic characters of their hosts. Thus, evolutionary relationships can be takeninto consideration by first doing a phylogenetic analysis of the parasites and then treating that cladogram as a multistate character tree of the hosts that are inhabited by theparasite species.Such a tree is constructed with a source of information that is not available instandard multistate analyses, namely the cladistic analysis of the parasites themselves.The characters have characters, so to speak, that are used to infer their relationship.Various methods exist for converting the topology of a phylogenetic into a matrixof numerical characters. This permits multiple parasite taxa to be analyzed simultaneously (a common data matrix), in order to generate host phylogenies (O’Grady andDeets, 1987).Additionally, historical approaches to ecology rely on an a priori phylogeneticanalyses. Replacing the names of the terminal taxa from the parasite cladogram withtheir respective ecological life history traits produces an ecological summary cladogram. The result is a spatiotemporal interpretation of the evolution of the parasites5infection-site associations (Brooks, 1985a; Deets, 1987). In the same vein, historicalapproaches to biogeography are analyzed by replacing the names of the terminal taxawith their distributions.Phylogenetic systematics has been applied mostly to free-living taxa. Onlyrecently has this method entered the field of parasitology. The first study to demonstratethe feasibility and applicability of cladistics with parasitic taxa was made by Brooks(1977). The phylogenetic relationships of plagiorchioid trematodes in this analysis wereshown to be congruent with their anuran hosts as well as exhibiting a definite vicariantdistribution consistent with the Pangaean breakup. This was followed by a series ofpapers utilizing cladistic methods on parasitic taxa including crocodilians and their digenean parasites (Brooks, 1979a), vicariance biogeography, potamotrygonid stingraysand their helminth parasites (Brooks, et. al, 1981), pinworms and primates (Brooks andGlen, 1982), nematodes and primates (Glen and Brooks, 1985; 1986), and otherpapers formulating other applications with cladistics and evolutionary theory (Brooks,1979b; 1980). Recently, Adamson and van Waerebeke (1985) employed cladistics toanalyze parasitic nematode classification and evolution, and Boeger and Kritsky (1989)tested Compagno’s (1977) various hypotheses of elasmobranch evolution with theircladistic analysis of the genera within the Hexabothriidae (Monogenea).In the midst of this blitzkrieg of phylogenetic analyses on worms, workers on theparasitic copepods (Crustacea), staging more of a sitzkrieg, gradually entered thecladistic arena. The first authors to investigate the phylogenetic relationships and historical zoogeography of a host group of fishes (Merluccius) as inferred from the phylogenetic relationships of their parasitic copepods were Kabata and Ho (1981). Though theirwork is free of any formal cladistic analysis, and devoid of associated jargon, it is phylogenetic in its approach. Both authors were keenly aware that when drawing conclusionson host zoogeographical or phylogenetic problems, one must be conscious of the phylogenetic relationships of the parasites considered. Hence, the relatively plesiomorphicor apomorphic conditions of the characters of their “indicator” species were taken into6consideration.Cressey, Collette and Russo (1983), specialists on parasitic copepods andscombrid teleosts, were the first authors to investigate phylogenetic relationships of parasitic copepods using formal quantitative cladistic methodology. Ho’s (1984) discoveryof the Spiophanicolidae, a family of highly modified copepods on polychaetes promptedhim to analyze phylogenetically a certain suite of poecilostomatoid families [informallytermed the Nereicoliform Group by Gooding (1963), IlIg, (1970) and Gotto (1979)] thatare parasitic on various invertebrate phyla. This resulted in the clarification of someclassificatory problems embedded in the literature for nearly 20 years. A year later, Hoand Do (1985) analyzed the genera in the Lernanthropidae, highly derived parasites ofteleost gills. That same year, Collette and Russo (1985) looked into the phylogeny ofthe Spanish Mackerels and their copepod parasites in order to determine which evolutionary events of the parasites could be explained by the evolutionary events of theirhosts. Following this, Deets (1987) conducted a phylogenetic analysis and systematicrevision of the genus Kroeyerina and a higher level analysis of the genera within thefamily Kroyeriidae. The apparent static nature of the parasites’ life-history traits (specificinfection sites) coupled with the congruent phylogenetic pattern with their elasmobranchhosts suggested both hosts and parasites experienced the same vicariant events andsubsequent allopatric speciation. After this work a phylogenetic analysis of theEudactylinidae (Deets and Ho, 1988), resulted in the resurrection of the previously synonomized genus Protodactylina Laubier, 1966. A Tethyan distribution was speculatedfor a single monophyletic subset (dade) of 3 monotypic genera parasitic on batoids.Next, Benz and Deets (1988), with the rediscovery of a rare parasite specific to mobulidbranchial filters, carried out a phylogenetic analysis of the genera within Cecropidae.Finally, Dojiri and Deets (1988) with the finding of a new genus Norkus (Sphyriidae)phylogenetically analyzed the sphyriid genera. Again tight phylogenetic congruencewith the hosts and parasites were the result. Additionally, parasite life history traits mirrored the cladogram’s topology.7In order to apply these methods and aforementioned concepts it is imprative topossess detailed knowledge of the studied taxon’s morphology. At present the morphology of parasitic copepods is only poorly known. It appears morphological details ofminute animals are often ignored just because of their dimunitiveness (Kabata, 1979).Kabata (1979) redefined the family Eudactylinidae and removed from it Kroyeriavan Beneden, 1853 and Kroeyerina Wilson, 1932 to form a new family Kroyeriidae.Recently, Deets (1987) established a new genus Prokroyeria to accommodateKroeyerina meridionalis Ramirez,1 975. The revised Eudactylinidae then consisted ofseven genera, but since then three have been discovered (Deets and Benz, 1987;Deets and Ho, 1988) bringing the total to ten, namely Bariaka Cressey, 1966;Carnifossorius Deets and Ho, 1988, Eudactylina van Beneden, 1853, EudactylinellaWilson, 1932, Eudactylinodes Wilson, 1932, Eudactylinopsis Pillai, 1966, HeterocladiusDeets and Ho, 1988, Jusheyus Deets and Benz, 1987, Nemesis Risso, 1826, andProtâdactylina Laubier, 1966.This elasmobranch-copepod system is a good model to work on for manyreasons. The host group has been shown to be monophyletic (Compagno,1977;Maisey,1984) , and this coupled with their antiquity as shown by paleontological data(Maisey, 1984) and molecular data (Davies, et al., 1986) should result in a host-parasite system with a strong historical core. The phylogenetic relationships of living sharksand rays remain unsettled partly because too few of the taxa have received investigation beyond the superficial statements needed for taxonomic identification (not unlikethe parasitic copepods), and partly due to the depauperate fossil record of extant andextinct elasmobranchs (Compagno, 1977). Other problems obscuring elasmobranchinterrelationships are their morphological conservatism and the fact that characterpolarity in elasmobranchs is difficult to define due to a lack of understanding of the characters in plesiomorphic outgroup taxa (Fechhelm and McEachran, 1984). Though thereare some phylogenetic analyses in the literature (Compagno,1977, 1984a,b, 1988;Maisey, 1984; Heemstra and Smith, 1980; Nishida, 1990 and Shirai 1992a, 1992b),8there is little agreement on any one phylogeny and it appears that more morphologicalwork and other modes of investigation (such as phylogenetic analyses of their parasites) are needed to to aid in resolution and/or corroboration of these issues.Additionally, the parasite species associated with this host group have not had sufficientattention paid to those morphological details that should be used for the specific discriminants in phylogenetic analyses, and therefore are in need of this revision.Specifically, this effort involves the previously discussed coevolutionary conceptsand cladistic methods, and empirically revolves around this fascinating complex(Eudactylinidae and Kroyeriidae) of parasitic crustaceans that inhabit olfactory andbranchial lamellae of an equally intriguing host group, the elasmobranchs. I intend toprovide a comprehensive taxonomic revision and phylogenetic analysis for the twogenera Eudactyilna and Kroyeria. Specific rationale regarding the choice of these twogenera follow.Eudactylina, world-wide in distribution, is found amongst the branchial lamellaeof a systematically broad range of elasmobranchs. It is the most species-rich genus ofany gill-dwelling group of parasitic copepods on elasmobranchs. The principal attachment organ is the large chetate maxilliped, reminiscent of the second antenna inKroyeria. Eudactylina exhibits a definite host preference for squaloid, squatinoid, pristiophoroid and batoid elasmobranchs (only 6 species found on carcharhiniform hosts).This host association for Eudactylina is very interesting as some elasmobranch systematists (Maisey, 1984; Shirai, 1992a, 1992b) have radically hypothesized that thissqualoid-squatinoid-pristiophoroid “shark” lineage to be more closely related to batoidsthan to the other “sharks”. The conventional notion of shark monophyly would therefore, degrade into paraphyly. Recently, this complex has been elevated to a monophyletic superorder the Squalea Shirai, 1992 when batoids and hexanchoids areincluded (Shirai, 1 992a). The Hypnosqualea of Shirai (1 992a) is a monophyletic subunit within the Squalea composed of the squatinoids plus pristiophoroids plus thebatoids, all hosts of Eudactylina. Hence, a taxonomic revision and systematic analysis9of Eudactyilna could aid in corroboration of this recently formulated, novel hypothesisthat not all sharks are sharks.Kroyeria occurs worldwide and is the second most species-rich genus of gill-dwelling copepods parasitic on elasmobranchs. All but one of the species are foundattached to the gill lamellae of their hosts (Benz and Dupre, 1987; Deets, 1987).Kroyeria caseyl Benz and Deets, 1986 is atypical of the entire family in that the femaleis mesoparasitic (fossorial, anterior portion of the animal usually modified into a hold-fast and rooted into the host tissue, posterior portion exposed and freely trailing),deeply embedded within the host’s interbranchial septa. The male of K. caseyl, likethose of other members of the genus, primarily attach themselves to the secondarylamellae and secondarily to the underlying excurrent water channels of their host’s gills(Benz and Dupre, 1987) by means of their modified chelate second antennae. The longvermiform body trails behind, nestled between the gill filaments of its host. The carcharhiniform families Carcharhinidae (requiem sharks), Sphyrnidae (hammerheadsharks) and the Triakidae (hound sharks or whiskery sharks) are the primary hostsreported for this genus. Although these families are closely related (Compagno, 1977,1988) phylogenetic relationships within this carcharhiniform complex are considered tobe in a state of disarray (Maisey, 1984). In fact, both morphological and molecular evidence continues to mount suggesting the possible paraphyly of the Carcharhinidae,Carcharhinus, and Triakidae (Compagno, 1988; Lavery, 1992; Naylor, 1992). A taxonomic revision and systematic analysis of Kroyeria, specific to the Carcharhiniformesmay assist in answering these aforementioned questions.This research therefore, is an effort to apply phylogenetic systematics or cladistics to this parasitic crustacean-elasmobranch host system in order to reveal and hopefully resolve the uncertain phylogenetic relationships of these hosts and parasites. Thiseffort proceeds by initial historical and biological reviews and the subsequent taxonomIc revision and redescription of two parasitic copepod genera, Eudactylina and Kroyeria.Additionally, both genera are in need of revision. Each revision is followed by a phylo10genetic analysis of that genus, from which parasite-derived host cladograms are constructed, and in two instances, area summary-cladograms are produced. Competingindependent host phylogenies are then compared with the parasite-derived host cladograms. Finally, the Kroyeria cladogram will be numerically recoded and combined withyet another recoded tree from a previous revision and phylogenetic analysis of the parasitic copepod genus Kroeyerina (cf Deets, 1987), into a common matrix to generate asingle host phylogeny based on all the parasite data from the Kroyeriidae.11MATERIAL AND METHODSChondrichthyan hosts were captured in three general localities. Specimens fromthe southern California bight (San Diego to Point Conception, California) were.obtainedfrom the San Pedro, California based commercial fishermen using set coastal gill netsand pelagic drift nets. Material from the Sea of Cortez or Gulf of California was caughtwith gill nets, long lines and harpoon by the fishermen at Bahia de Los Angeles andPunta Arena de Ia Ventana. Sampling proceeded intermittently from October 1980,through January 1994.Additionally, type and non-type material was obtained from the U.S. NationalMuseum of Natural History, Washington, D.C., U.S.A., The Natural History Museum,London, England, and the Museum National D’Histoire Naturelle, Paris, France.Specimens were also received from the Instituto de Biologia Marina, Mar del Plata,Argentina and Instituto de Investigaciones Oceanologicas, Universidad de Antofagasta,Antofagasta, Chile. The California Academy of Sciences in San Franciscq and theNational Museum of Natural History, Smithsonian Institution’s support center allowedme to inspect preserved elasmobranchs for parasitic copepods during my short-termvisitor appointment in June of 1 988.Additional specimens were donated to me from the personal collections ofGeorge Benz, (Tennessee Aquarium); Dr. Roger Cressey, (National Museum of NaturalHistory, Smithsonian Institution), Dr. Ju-Shey Ho, (California State University, LongBeach), Dr. Z. Kabata, (Pacific Biological Station, Nanaimo, British Columbia), and RaulCastro Romero, (Universidad de Antofagasta, Antofagasta, Chile).Parasites recovered from the host’s branchial and olfactory lamellae were immediately preserved and subsequently stored in 70% ethanol. Later, copepods werecleared in 85% lactic acid, lightly stained with lignin pink, and transferred to wooden12slides according to procedures of Humes and Gooding (1964). The parasitic copepodswere then dissected to permit a detailed morphological examination of the appendages.All drawings were made with the aid of a camera lucida. Illustrations were drawn onCanson Vidalon Tracing Vellum, no. 110 (extra heavy), and inked with RotringRapidograph technical pens.Phylogenetic analyses were carried out using the following protocol:Eudactylinodes Wilson, 1932, recently revealed to be the sister taxon of Eudactylina,and at times Eudactylineila, Carnifossorius, and Eudactylinopsis, sister group to theEudactylina-Eudactylinodes dade (Deets and Ho, 1988), functioned as outgroups forEudactylina. Kroeyerina, the sister taxon to Kroyeria, and at times, Prokroyeria mendlonalis (Ramirez), the most basally placed member of the Kroyeriidae (Deets, 1987)were chosen as outgroups for Kroyeria. These outgroups were selected in order todetermine character polarity for their respective ingroups.Character data were defined, produced and coded (see appendices). All character data were treated and analyzed as unordered to avoid risk of predetermining thetopology of the resultant cladogram (O’Grady and Deets, 1987; Dojiri and Deets, 1988).Non-linear, multistate transformation series (the recoded cladograms) were standardized by coding techniques reviewed and outlined by O’Grady and Deets (1988). Uponcompletion of the character data matrix the computer program PAUP (PhylogeneticAnalysis Using Parsimony; D. Swofford, U.S. National Museum of Natural History,Smithsonian Institution, Washington, D.C., 20560) version 3.OS was used to analyzethe data. Specifically, the exact search algorithm BRANCH AND BOUND for small datasets and the heuristic search algorithm TREE-BISECTION AND RECONNECTION(TBR) for large data sets, were utilized to generate the most parsimonious hierarchy ofparasite and parasite-derived host relationships. The computer program MacGlade (W.Maddison and D. Maddison, University of Arizona) version 3.0 was used interactivelyas a tool to increase insight on character evolution.Parasite cladograms were perceived as character state trees of their hosts, con-13verted into numerical codes, combined and placed into a data matrix and phylogeneticafly analyzed in order to generate the final host phylogenies (Brooks, 1981; Brooksand McClennan 1991, 1993).Elasmobranch figures were lifted and modified from Last and Stevens (1994),and from Stevens (1987).14HISTORICAL REVIEWSince their inception in 1853 neither Eudactyilna van Beneden or Kroyeria vanBeneden have suffered any nomenclatural restructuring. However, they have experienced some shuffling at the familial level. Originally, both genera were assigned to theconvenient catch-all taxon Dichelesthiidae, the “tribu des Dichelestiens” of Edwards,1840. (For a comprehensive review of the history of Dichelesthiidae, see Kabata,1979). In 1853 the family was composed of the genera Anthosoma Leach, 1816,Dichelesthium Hermann, 1804 and Nemesis Risso, 1826.Streenstrup and Lutken (1861) accepted “Dichelestiner” as a valid higher taxon.They included in it more genera than any previous authors, namely: Anthosoma,Congericola van Beneden, 1854, Dichelesthium, Eudactylina, Kroyeria, Lamproglenavan Nordmann, 1832, Lernanthropus de Blainville, 1822, Nemesis and Pagodina (=Nemesis). The concept of Dichelesthiidae was similar in the work of Krøyer (1863,1864), and von Nordmann (1864) used the structure of the egg sacs as the basic division between the genera. His group “Dichelestini” with filiform uniseriate egg sacs (asdisfinct from saccular multiseriate) consisted of: Anthosoma, Congericola,Dichelesthium, Donusa Nordmann, 1 864, Ergaslilna van Beneden, 1851 (= Nemesis),Eudactyilna, Kroyeria, Lamproglena (a cyclopoid), Lernanthropus, Nemesis, Pagodinaand Stalagmus Nordmann, 1864 (Donusa, Ergasillna, Pagodina, and Stalagmus are nolonger valid taxa).It wasn’t until Heller (1865) provided a key to the “Familia Dichelestina” thatsomeone offered an idea of intrafamilial groupings by way of a key to the genera.Pagodina was concomitantly synonomized with Nemesis.A similar approach to dichelesthiid systematics was followed by Gerstaeker(1866-1879). His key to the family “Dichelesthiina” included the following genera:Aethon Krøyer, 1857, Anthosoma, Bacculus Lubbock, 1860 (larval stage of PennellaOken, 1816), ClavelIa (= Hatschekia Poche, 1902), Congericola, Dichelesthium,Donusa (a polychaete parasite, probably a cyclopoid), Epachthes Nordmann, 1832(syn. of Lernanthropus), Ergasilina (syn. of Nemesis), Eudactylina, Kroyeria,Lamproglena, Lernanthropus, Nemesis, Norion Nordmann, 1864, PhilichthysSteenstrup, 1862 (type genus of Philichthyidae), Pseudocycnus Heller, 1865,Stalagmus (syn. of Lernanthropus) and Tucca Kreyer, 1837 (a poecilostome).Brian (1 906) along with Scott and Scott (1 91 3) included subsets of above in theirtreatment of Dichelesthiidae with representatives from their restricted areas of study,15Italian and British waters respectively.Therefore, Dichelesthiidae with its vague and over inclusive diagnostic boundaries functioned as a depository for many new genera and species that could not beaccommodated in other existing well-defined families.Wilson (1922), offered the first review of intrafamilial organization of theDichelesthiidae by generating a key to subfamilies. In his Copepoda of the Woods HoleRegion, Wilson (1932) upgraded the status of his four subfamilies and established thefollowing families with their respective genera:Anthosomidae (Anthosoma, Lernanthropus);E udacty Ii n idae (Kroyeria, Kroeyerina, Nemesis, Eudactyilna, Eudactylinodes,Eudactylinella);Pseudocycnidae (Pseudocycnus);Dich e lesth i idae (Hatschekia, Pseudohatschekia, Pseudocongericola, Lamproglena)Dichelesthium was excluded due to its abscence from the Woods Hole Region.Yamaguti (1939) accepted the familial rank of these four families, whileMarkevich (1956) kept them as subfamilies and transferred Lamproglena (thecyclopoid) to Eudactylinidae from Dichelesthiidae. Later Yamaguti (1963) reunitedWilson’s four families by establishing the superfamily Dichelesthioidea.Kabata (1979), at wits end, realized the lack of relationship between the variousgenera within these families, and the lack of affinity amongst the families embedded inYamaguti’s Dichelesthioidea and systematically restructured this taxonomic complex.Using body segmentation for the first time as the primary criterion for classification Kabata, (1 979) distinguished six groups of genera within this miscellaneous assemblage previously recognized as Dichelesthiidae. Additionally, the cephalothoracicappendages that each of these groups posess were shown to be unique. Witness thechelate second antennae of Kroyeriidae or the chelate maxiliipeds of Eudactylinidae.Coupled to this, one find similar patterns with the swimming legs. Compare the fourpairs of well developed, non-modified biramous, trimerite swimming legs of Kroyeriidaewith the four pairs of Hatschekiidae, which have very reduced third and fourth legs andoften only bimerite rami of legs one and two as examples. These pieces of evidenceadd layers of justification or corroboration to the groups distinguished by Kabata’s tagmatic criterion. On the basis of these and many other arguments outlined in Kabata(1979), the following family units were proposed in accordance with this key:161. Four distinct segments between cephalothorax and genital segment EudactylinidaeThree segments (exceptionally four) between cephalothorax and genital trunk 2Segmentation indistinct, neck present between cephalothorax and genital trunk 3No free segments or neck between cephalothorax and genital trunk, dorsal plate usually present ontrunk Lernanthropidae2. Free segments distinct, cephalothorax with caligiform dorsal shield, four pairs of biramous legsKroyeriidaeFree segments rather indistinct, dorsal shield of cephalothorax not caligiform, three pairs of variouslymodified legs, elytra absent Dichelesthiidae3. Second maxilla with bifid claw, maxilliped absent HatschekiidaeSecond maxilla with simple, denticulated claw, maxilliped present, subchelate. . PseudocycnidaeOne genus, Pseudohatchekia Yamaguti, 1939, cannot be accommodated in anyof these previous six families. If Yamaguti’s illustrations accurately represent the morphological attributes of this genus, it would seem a new family (Pseudohatchekiidae)should formally be established upon inspection and revision of the species therein.So, after 140 years of a tightly coupled and shared systematic history, in spite oftheir obvious morphological disparities (perhaps due to both being parasites of elasmobranchs) the paths of Eudactylina and Kroyeria diverge, finally finding their way intotheir own families, Eudactylinidae and Kroyeriidae, respectively.17EUDACTYLINAEXTERNAL MORPHOLOGYGENERAL HABITUSThe body of Eudactylina is typically sub-cylindrical with seven distinct tagmata(Figure 2a): the cephalothorax (which consists of the somites bearing the first antenna,second antenna, mandible, first maxilla, second maxilla, maxilliped, and the first pedigerous somite), the well-developed pedigerous somites two, three, and four (bearingbiramous and usually trimerous legs), a reduced pediger five (bearing a reduced fifthleg), a genital segment (bearing the genital orifices), and a multi-segmented abdomen(posteriorly bearing the caudal rami).The cuticle is equipped with posteriorly directed cuticular expansions. Thesecuticular flaps or outgrowths vary in size and shape from species to species, therebypossessing some taxonomic importance. Eudactyilna orients itself upstream relative tothe flow of water over the gills (Figure 1), and these posterorly directed flaps may function as tiny brakes keeping the parasite relatively secured at that location on the gill.The cephalothorax houses the main “organs” (appendages) of attachment forEudactyilna. These are the first antenna with a few setae modified into large claws onthe second and third segments, the second antenna with its uncinate apical segment,and primarily the huge robust chelate maxilliped.The major articulation of the body is between the fifth pedigerous somite and thegenital somite.The genital somite of the female appears to be located on the sixth thoracicsomite. Close examination of the ventrolateral area adjacent to the oviducal openingsreveal three well developed albeit small spines (Fig. 3D detail) which most likely represent the vestigial sixth legs. Additionally, the position of this putative sixth leg roughlycorresponds to the position that the reduced sixth leg occupies on the male. If thishomology in structure and position is true, then it is likely that the abbreviated numberof segments in the abdomen of the female (two) relative to the supposedly more pIesiomorphic condition of the male (three or four segments), is due to the suppresion notincorporation (into a genital complex) of these somites during ontogeny.18CALJDALRAMUSThe caudal rami originate posteriorly from the last abdominal somite. The caudal ramus is undoubtably an organ of slippage prevention. The parasite plunges thepaired rami down into the secondary lamellae of the host’s gills (Figure 1), helping towedge the entire animal in place amongst the secondary lamellae. It seems the posteriorly-directed cuticular flaps on the ventral surface of the rami coupled with the welldeveloped, often digitiform terminal spines (modified setae) suggest a stopping function. Within the genus caudal rami vary markedly in form, from the relatively unmodified state possessing four relatively long pinnate apical setae plus two relatively longnaked setae as seen in the male Eudactylina epaktolampter (Figure 22B), to theextremely derived condition of possessing four stout apical spines barely larger thanthe adjacent cuticular flaps as in female Eudactylina oliveri (Figure 36B), and thebizarrely modified digitiform condition found in the female of Eudactylina dactylocerca(Figure 14B). The striking differences exhibited by the caudal rami between the different species of Eudactyilna make this a useful taxonomic character.FIRST ANTENNAThe first antenna of female Eudactylina (Figure 2C) is indistinctly four-, five- orsix-segmented, exhibiting geniculate flexion between the second and third segments.Although no physiological work has been done on this appendage it is safe to presumesimilar (homologous) innervation exists here as seen in other siphonostome copepodsindicating an organ capable of chemosensory and tactile functions (see Kabata, 1979).Additionally, the large dorsally-directed claw-like spine (often toothed) on the secondsegment would seem to be an auxiliary attachment structure especially in light of theway the parasite lodges its cephalothorax into the secondary lamellae of the gills(Figures 1A, 1B). The first antenna of the male has a greater number of more clearlydelimited segments. The males of E. epaktolampter and E. oliveri (Figures.22C and38C, respectively) have eight or nine segments, and more setae are found on the segments. In general (with regards to the female) the first or basal segment always bearsone small seta on the outer margin. The apical segment appears to possess a maximum of 14 setae plus one aesthete. Although some descriptions in this revision and byother authors show fewer setae I believe some of this may be an artifact of specimendamage coupled with the fact we are pressing the limits of light microscopy with theminutiae involved.19The remaining segments between the basal segment and apical segment exhibit different degrees of fusion or segment incorporation in the different species.SECOND ANTENNAThe second antenna (Figure 2D) is five-segmented, not sexually dimorphic.The basal segment is small, unarmed and pedunculate. The second segment is relatively elongate, sometimes armed with a styliform process (appears to have a prehensile function), and sometimes possessing cuticular flaps. The third segment usuallybears a large claw-like extension and always has two slender setae at its base andcuticular flaps. The fourth segment sometimes exhibits cuticular flaps. The fifth segment forms a large uncinate terminal claw bearing a large accesory spine on the lateralsurface. Two small slender setae are always found at the base of the fifth segment.The many different combinations and states of these characters listed abovemake the second antenna an important taxonomic discriminant.ORAL CONE and MANDIBLEThe mandible is typically siphonostome being a uniramous subcylindrical structure with a dentiferous distal end (Figure 2E). The mandible also appears to be dividedinto two parts, their boundaries demarcated by a suture. The dentiferous margin bearsfrom five to eight teeth.The oral cone (Figure 36D), consisting of labium and labrum houses themandible. The possession of the mouth tube is the distinguishing characteristic of thesuborder Siphonostomatoida. The structure is rather uniform throughout the genuswith some differences seen in the nature of the cuticular flaps found on both the labiumand labrum. The use of this structure for systematic purposes was not pursued.FIRST MAXILLAThe first maxilla found adjacent to the mandible is the first segmental appendagefound in the post-nauplial stages of copepods (Kabata, 1979). It is biramous consistingof an endopod and an exopod (Figure 2F). The exopod is armed with two setae whichmay bear setules or denticulations. The endopod terminates with one long seta and twoshort setae the former bearing setules or small denticulations in certain species. The20body of the first maxilla also bears small spinulations or cuticular flaps in some species.SECOND MAXILLAThe second maxilla is a large brachiform appendage (Figure 2G). The orifice ofthe maxillary gland is present at the base as is the basal process, a small fleshy extension of cuticle. The most proximal segment is the lacertus. The lacertus is typically “fortified” by the presence of well developed sclerites, and is armed with cuticular flaps.This segment articulates with the brachium by means of the cubital joint. The brachiumis also armed with the cuticular flaps and distally bears what appears to be a tuft orpaired tuft of setae, and a patch of prickles or denticles termed the crista at the base ofwhat may represent a third segment the calamus or claw. The claw usually bears aseries of comb-like serrated membranes or, as in a few species, well developed teeth.Although the comb-like membranes suggest a grooming function, the closely relatedspecies Nemesis robusta (van Beneden, 1851) also a member of Eudactylinidae hasbeen shown to use the second maxilla to assist in feeding on the secondary lamellae ofthe thresher shark (A/op/as vulpinus (Bonnaterre, 1758)). Feeding by these gill parasites involves the mechanical rasping of host tissue and the second maxillae wereshown in histological sections to be the appendage responsible for host tissue excavation (Benz and Adamson, 1990). The second maxilla has also been implicated inmanipulation of the frontal filament during the developmental stages of most siphonostomes in which they are known (Kabata, 1979). Unfortunately, the specific function ofthe second maxilla in Eudacty/ina is unknown.MAXILLIPEDThe maxilliped is the posteriormost oral appendage borne upon the first thoracicsegment incorporated into the cephalon. Sexually dimorphic, the male maxillipedoccurs as a sub-chelate structure (Figure 22D), while the female form exists as aremarkable, fully chelate structure (Figure 2H). The female maxilliped appears to consist of four segments. The unarmed pedunculate basal segment supports the mainbody or corpus maxillipedis. The corpus maxillipedis is always armed with cuticularflaps, a small spine-like seta, at times a lateral flange, and a greatly produced posterolateral region, the myxa, forming a large scoop-like receptacle. By means of the cubitaljoint the corpus articulates with the subchela. The subche!a is composed of the proximal shaft bearing one seta approximately midway along the outer margin and another21located distally near the base of the claw along the inner margin. A membrane is alsofound adjacent to the latter along the inner margin of the most distal reaches of theshaft. The shaft may bear cuticular flaps. The most terminal segment of the subchela isthe claw. This is an uncinate structure accompanied along the lateral surface by aquadrangular expansion of varying sizes. When clasped, the claw and quadrangularexpansion are perfectly accommodated by the receptacle-like myxa, forming a pincer.This structure is the primary attachment appendage that the copepod uses to grip thesecondary lamellae of the host’s gills (Figure 1).LEG ONEThe first thoracic leg is the only leg incorporated into the cephalothorax (Figures2A and 3A). The pair of legs is connected by an interpodal bar allowing their synchronous movement. The sympod is well delimited by a media’ suture separating the proximal coxa from the adjacent basis. Both coxa and basis are armed ventrally with cuticular flaps or scales. The basis bears one lateral and one somewhat medial seta along itsdistal margin. The leg is always biramous, composed of a lateral exopod and a medialendopod. Both rami are usually three-segmented (trimerous) and rarely bimerous. Theproximal (first) and middle (second) segments of the exopod bear a distolateral spine-like seta (pinnate setae are found in legs one through four in the male). The terminal(third) segment typically bears three or four variously modified setae. The endopod isalso a trimerous or rarely bimerous ramus with only the terminal segment armed withtwo setae.LEG TWOThe second thoracic legs (Figure 7B) are united by an interpodal bar. In a fewspecies the interpodal bar of leg two has a non-articulated medial extension creating asingle ventroposteriorly directed interpodal stylet (Figure 15C). The coxa and basis aredistinct, with the basis armed with one seta along the distolateral edge. The secondthoracic appendage is also biramous, with both rami trimerous except in a few cases inwhich the endopod is two-segmented. The terminal segment of the endopod carries twosetae. The exopod with few exceptions (e.g., E. acanthi,) is a bizarrely modified ramus.It has few if any cuticular flaps, in contrast to the other three leg pairs. The proximalsegment is greatly enlarged, often tremendously elongate and bears a single curved22spine distolaterally. The middle segment is armed with a single spine-like seta of various sizes. The terminal segment is reduced in size bearing a small lateral seta, an oddquadrangular or thick seta is found terminally and a strongly hooked seta located onthe medial margin of the segment. The sometimes strongly produced spine on the middle segment and the strongly hooked seta on the medial edge of the terminal segmentwhen viewed in context with the in situ illustration of Figure 1, suggests the ramus functions in slippage prevention if not as an auxiliary attachment appendage.LEGS THREE AND FOURThe third and fourth pairs of legs (Figure 3C) are nearly identical in all species ofEudactylina with the exception of E. doilfusi where the endopod of the fourth leg ismodified into a robust uncinate process (Fgure 19D). Each leg pair is joined by aninterpodal bar. In a few species the interpodal bar of leg three has a non-articulatedmedial extension creating a single ventroposteriorly directed interpodal stylet (Figure33E). Both pairs of legs are adorned with cuticular flaps. The sympod is well delimitedinto a proximal coxa and more distal basis. The basis bears a single spiniform seta onthe lateral margin. Both legs are biramous and the rami trimerous with the appearanceof a few bimerous endopods on leg four being the exception. The terminal segmentbearing a single seta is the only setal armature found on the endopod. The exopodbears a single spine-like seta on both segment one and two, and three spine-like setaeon the terminal segment. The third and fourth pair of legs with their posteriorly directedcuticular flaps probably aid in slippage prevention. Additionally, Figure 1 showsEudactylina using their endopods and exopods independently, in fact, at right angles toeach other to what appears to be separating the secondary lamellae in order to moresecurely wedge itself amongst the lamellae. This would seem to cause the secondarylamellae to attempt to return to their normal positions possibly pressuring or pushingback down and around the parasite aiding in its attempt to remain securely affixed tothe host tissue.LEG FIVEThe fifth leg is a uniramous, one-segmented appendage found on the last andfourth free thoracic somite (Figure 2A and 3D). The sympod consists of a single segment and a small seta is found distodorsally. The ramus bears three naked or pinnate23slender setae distally. Depending on the species, both sympod and ramus may beunarmed or covered with cuticu tar flaps.The sixth leg of the female is rarely seen (or looked for) as it appears to be composed of three minute stout spine-like setae adjacent to the opening of the oviducal orifice (Figure 3D detail) on the genital segment. The sixth leg of the male is found on thedistolateral edge of the genital segment. It is represented by two or three setae arisingfrom a small flap, presumably the sympod (Figure 22A and 23G).LIFE HISTORYGENERAL DESCRIPTIONThe first mention of a larval eudactylinid was given by Wilson (1922) forEudactylinodes nigra. Devoid of illustrations, the narrative description tells us littlemore than that the organism was a nauplius. The next time any mention of aeudactylinid larva appears is by Kabata (1976) for Eudactylina similis. Unfortunately,Kabata was unable to culture the parasite beyond the first naupliar stage. Hence, nothing is known about the infective stage of Eudactylina.In general, most fish-parasitizing siphonostomatoid copepods with known onto-genies possess a three part post-embryonic development consisting of the nauplius,copepodid, and adult (Raibaut, 1985) . The number of naupliar stages varies from oneto six. Next is a single copepodid stage, followed by four modified copepodite stages,chalimus I - IV, that possesses, in many but not all species, the remarkable anchoringdevice, the frontal filament. According to Raibaut (1985), the frontal filament is formedduring the copepodid stage and is extruded for attachment to the host immediately priorto the molt into the first chalimus stage. In contrast, Wilson (1911, P1. 30, Fig. 10)shows a nauplius of the Iernaeopodid, Achtheres ambloplitis with an already formed,coiled frontal filament. Although this chalimus larva had been considered to be presentin all of the siphonostome copepods of fish, Cabral, Coste, and Raibaut (1984•) demonstrated this was not the case. Experimental infestations of Lernanthropus kroyeri vanBeneden, 1852 on Dicentarchus labrax (Linne,1758) revealed that this species possessed two free swimming naupliar stages but lacked the chalimus stages. It did haveone free living copepodid stage followed by the infectious second fixed copepdid. Fixedcopepodids Ill, IV and V preceeded the two sub-adult stages before finally transforminginto the adult. Furthermore, Kabata and Khodorevski (1977) described a copepodid,not a chatimus, from another gill inhabiting siphonostome Dichelesthium oblongum24(Abildgaard, 1794). The fact that I could not find any evidence of any frontal filamentremnants or frontal gland scars on the many eudactylinids I have examined suggeststhat a similar life cycle prevails in this group of copepods. It can be presumbed thatthey become infective as copepodids, attach themselves presumably with the secondantennae and maxillipeds, suppress or skip the chalimus stage and molt finally into thepre-adult or adult stage. Indeed, Kabata (1981) suggests with regard to the absence ofthe frontal filament in the relatively primitive (minimal cephalization) siphonostomeDissonus nudiventris that the frontal filament is probably a relatively derived character.Additionally, the majority of fish parasitizing siphonostome copepods exhibit aholoxene or direct life-cycle, requiring only a single host to live out their life. Again theevidence suggests this is probably the case with the eudactylinids, if not all of the gilldwelling families of possible dichelesthoid affinities (Eudactylinidae, Kroyeriidae,Hatchekiidae, Lernanthropidae and Dichelesthiidae).REPRODUCTIONCopulation apparently occurs between the adult stages of the parasites. I haveobserved preserved specimens in the presumed copulatory embrace similar to whathas been described by Benz and Adamson (1990) for Nemesis robusta (van Beneden,1851), also a member of the Eudactylinidae parasitizing the common thresher shark(Alopias vulpinus (Bonnaterre, 1758)). The male attaches to the female using the prehensile second antennae and subchelate maxillipeds. The male then somehow transfers two spermatophores to the lateral surfaces of the female’s genital segment whichattach at the female’s oviducal openings (Figure 3D and 16A) (see Benz and Adamson,1990 for a detailed description of the morphology and attachment of the brown bodyand seminal vesicle in N. robusta). When the eggs exit the oviducal opening, they arefertilized by the males gametes from the seminal receptacle. Ovigerous females produce uniseriate egg sacs, presumably secreted by cement glands located in the genitalsegment.25HOST-PARASITE RELATIONSHIPSDELETERIOUS EFFECTS / FEEDINGEudactyilna always attach themselves to the secondary Iamellae of their elasmobranch host’s gill, principally by their clasping chelate maxilliped (Figure 1). Whenextracting these parasites from the gills I have never observed gill tissue pathologiesinduced by Eudactyilna. Certainly, some damage is being done since most of the specimens still had gill tissue gripped in their maxillipeds which had to be carefully removedbefore the microscopic examination and illustrations could proceed.Additionally, over the last 14 years of collecting Eudactylina from elasmobranchgills I have observed a general trend for this genus to exhibit a rather low parasite loadrelative to other elasmobranch gill infecting siphonostome genera such as Nemesis andKroyeria. For example, the maximum number of Eudactylina acanthil A. Scott, 1901 Icollected from a spiny dogfish (Squalus acanthias Linnaeus, 1758), was 60 (ayerage offive specimens was 35). Similarly, a single Pacific electric ray (Torpedo cailfornica,Ayres) yielded a maximum of 77 Eudactylina similis T. Scott, 1902. These maximumnumbers are reported here because it is very common to recover less than five individual Eudactylina from a single batoid or squaloid host.Because individual Eudactylina seem to be attached to the secondary lamellae,presumably they feed directly on these respiratory surfaces. Unfortunately, no studieshave been done on gut contents in Eudactylina. Benz and Adamson (1990) studiedhistological sections in the closely related eudactylinid Nemesis robusta, and founddark staining granules (partially digested blood?) reminiscent of those commonly foundin the diverticula of haematophagus monogenetic trematodes.SPECIFICITYEudactylina exhibits a high degree of both ecological and host specificity.General observations reveal Eudactylina to distribute itself in no apparent pattern orpreferred areas across the host’s hemibranchs, and Eudactyilna will only be found onelasmobranch gills. Regarding host specificity, the majority of the species ofEudactylina are specific to a given host species or genus, making them good biologicaltags. A few species are apparently more flexible with their choice of hosts but still showspecifity at a more general level in the hierarchy, restricting themselves to hosts within a26given family. Specifics are detailed in both the taxonomic account and phylogeneticanalysis below.SYSTEMATIC ACCOUNTGenus Eudactylina van Beneden, 1853Eudactylinidae: Female. Cephalothorax covered by well demarcated dorsal shield; foursucceeding thoracic segments bearing cuticular flaps on terga. Genital segment small,quadrate and bearing oviducal openings and reduced uniramous leg five. Abdomentwo-segmented. Caudal ramus bearing from four to six sometimes modified setae.Posteriorly directed cuticular flaps present on ventral surfaces of genital segment,abdomen, and caudal ramus.First antenna indistinctly four to six segmented with geniculate flexion betweensecond and third segments. Second segment bearing large curved prehensile claw.Terminal segment generally bearing one medial seta, one lateral aesthete, plus an additional 13 to 14 slender setae. Second antenna five-segmented with prehensile terminalclaw. Mouth tube siphonostome. Mandible two-segmented; distal end dentiferous,bearing five to eight teeth. First maxilla biramous with endopod and exopod armed withthree and two apical setae respectively. Second maxilla brachiform, two- possiblythree-segmented. Maxilliped chelate, myxa produced into a large expanded receptacle.Legs one through four biramous, rami bimerous to trimerous. Exopod of leg two usually,though not always, modified (cf. E. acanthi,). Leg five one-segmented and uniramousbearing three distal setae. Leg six represented by three minute spines at oviducal orifice.Male: Similar to female. Abdomen three- to four-segmented. Caudal ramus lessmodified. Maxilliped subchelate, myxal area bearing a strong spinous process. Firstfour pairs of less modified legs, with more plesiomorphic armature (long pinnate setae).Leg six on posterolateral edge of genital segment represented by two or three setae.TYPE-SPECIES: Eudactylina acuta van Beneden, 1853.COMMENTS: In spite of the general uniformity of habitus, the species in thisgenus differ from another in a multitude of structural details such as morphology of thecuticular flaps, armature of the second antenna, armature and segmentation of thoracic27legs and in specific character attributes of the caudal ramus.Currently, Eudactylina consists of the 26 species illustrated and phylogeneticallyanalyzed herein plus 12 nominal but unfortunately for this investigation unobtainablespecies, bringing the total to 38. The unobtainable nominal species will be reviewed atthe end of the following section. An additional four species (E. carchariaeglauci Hesse,1884, E. mustelilaevis Hesse, 1884, E. puriensis Tripathi, 1956, and E squatinaeangeliHesse, 1884) have been inadequately described to be recognized and are consideredspecies inquirendae. The majority of the species described are parasites of squaloids(dogfish, lantern sharks), squatinids (angel sharks), pristiophorids (sawsharks), andbatoids (skates, guitarfish and rays). The remaining species are found on theCarcharhinidae (requiem sharks) and Sphyrnidae (hammerheads). There are approximately 350 species of “sharks” (Compagno, 1984a), and 425-450 species of rays(Eschmeyer et al, 1983), and only 38 species of the highly host specific Eudactylina areknown. This information suggests this genus is potentially enormous with many morespecies waiting to be discovered.Eudactylina acanthil A. Scott, 1901(Figures 2-3)Material examined. Several co-type females, BMN H 1911 .11 .8.48318-322,1913.9.18.272-281, 1963.4.29.15, 1975.379-392 from British waters. Many femalesfrom the Vancouver Island region on loan from Dr. Z. Kabata, Pacific Biological Station,Nanaimo, British Columbia. Numerous females from the southern California Bight. Allspecimens were found attached to the branchial lamellae of the spiny dogfish, Squalusacanthias Linnaeus (1758).DescriptionFemale (Figure 2A)Overall length in lateral view approximately 2.25 mm. Cephalothorax longer thanwide, lateral margin notched accomodating the second maxillae. Ventrolateral marginof cephalothorax bearing small cuticular flaps. Tergum of first free thoracic somite withsmall cuticular flaps on ventrolateral margin. Second and third free thoracic somiteswith naked and indistinct terga. Fourth free thoracic somite bearing fifth le smallerthan previous two. Genital segment smaller than preceeding somite. Abdomen two-segmented, second segment ventrally bearing cuticular flaps. Caudal ramus (Figure25) longer than wide, bearing four terminal naked setae, one slender, medial seta, andone lateral naked seta; ventral surface armed with posteriorly directed cuticular flaps.28First antenna (Figure 2C) indistinctly five- or six-segmented, armature (proximalto distal) as follows: one stout seta, one small spinule, eight stout setae plus one largecurving (prehensile) claw, nine stout setae, one short seta, 14 slender setae plus oneaesthete. Second antenna (Figure 2D) five-segmented, uncinate, prehensile. Basalsegment stout, second and third segments with sparse cuticular flaps, third segmentbearing two slender setae arising from atypically reduced spinous process. Fourth segment elongate and unarmed; fifth segment an unciform terminal claw bearing two slender setae and one stout auxiliary spine approximately 1/4 length of claw. Mouth tubesiphonostome and similar to that of other species. Mandible (Figure 2E) of two parts,dentiferous margin with six teeth. First maxilla (Figure 2F) biramous; endopod bearingtwo apical setae; exopod longer surmounted by two stout setae and one longer bilaterally denticulated seta. Second maxilta (Figure 2G) brachiform, lacertus larger thanbrachium armed with triangular cuticular flaps, brachium with triangular cuticular flapsand a tuft of coarse, sparse setae at base of terminal claw (calamus). Claw bearingtwo rows of denticles and proximal serrated membrane. Maxilliped (Figure 2H)chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedisrobust, bearing small stout spine on distal margin; myxal area expanded into largereceptacle to accommodate claw of opposable chela. Shaft with single spine on lateralconvex margin and strip of membrane along concave distal margin. Claw unciform withquadrangular cuticular expansion producing lateral shield.First four pairs of legs biramous with three-segmented rami and two-segmentedsympods. All basipods with lateral slender seta; first basipod bears additional distomedial seta. Ventral surfaces of all four legs bearing triangular cuticular flaps. Armature oframi as follows: (non-pinnate setae in Roman numerals, pinnate setae (bearingsetules) in Arabic numerals).Leg one Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg two Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 Ill Endopod 0-0 0-0 ILeg one (Figure 3A) terminal segment of exopod compressed bearing two smallspiniform seta, lateral seta with single denticle; terminal segment of endopod with twomost lateral setae denticulated, most medial seta papilliform. Leg two (Figure 3B) withatypically unmodified exopod, all setae on exopod and endopod spiniform and smooth.Legs three and four (Figure 3C)similar; all setae spine-like and denticulated3terminalsegment of endopod compressed. Leg five (Figure 3D) suboval; distally bearing three29long slender setae plus one similar seta arising dorsally from the base. Leg six (Figure3D detail) represented by three small, stout setae on a posterodorsal ridge adjacent tothe oviducal opening.Male: UnknownComments: Kabata (1979) mentions the possibility of misinterpreting cuticularflaps for the very tiny spine-like setae and vice-versa on the swimming legs of E. acanthiL In spite of this word of caution, I have found the number of apical elements onendopods one, two, three, and four to be two, two, one, and one respectively, in contrast to Kabata’s three, three, three, and three, the former being generally more consistent with the endopodal formula exhibited by the genus.Eudactylina typically exhibits a bizarrely modified exopod on leg two. Thisspecies however stands out as the anomaly within the genus in possessing a normalendopod (resembling endopods of legs one, three, and four).All previous host records of Eudactylina acanthii come specifically from thebranchial lamellae of the spiny dogfish Squalus acathias. Like most parasitic cope-pods, the geographic range of this parasite is coincident with that of its host. This cope-pod has been reported from the Irish Sea, eastern and western North Atlantic, Sea ofJapan, Vancouver Island region, coastal Angola in the southern Atlantic (see Kabata,1979), Quehui, Chiloe’, Chile (Castro and Baeza, 1991), and now from southernCalifornia waters.Eudactylinaacuta van Beneden, 1853(Figures 4-5)Syn: Eudactylina complexa Brian, 1924 (see Kabata, 1979)Material examined. Several females, MNHN, CP 156 and CP 173 from thebranchial lamellae of the angelshark, Squatina squatina (Linnaeus, 1758) restricted tothe western North Atlantic and the Meditteranean (no specific site collection data).DescriptionFemale (Figure 4A)Overall length in lateral view approximately 3.3 mm. Cephalothorax longer thanwide, lateral margin notched accomodating lacertus of second maxillae. Ventrolateral30and dorsal surfaces of cephalothorax bearing small cuticular flaps. Tergum of first freethoracic somite with small cuticular flaps on dorsal surface. Second and third free thoracic somites with cuticular flaps on the dorsal surface and distinct terga. Fourth freethoracic somite smaller than previous two, bearing leg five. Genital segment smallerthan preceeding somite, with cuticular flaps on ventral surface. Abdomen two-segmented, ventral surface bearing cuticular flaps. Caudal ramus (Figure 4B) longer than wide,bearing two terminal stout setae, one slender medial seta, and one lateral naked seta;ventral surface armed with patches of posteriorly directed cuticular flaps. Oviducalopening dorsal, egg strings uniseriate (Figure 4C).First antenna (Figure 4D) indistinctly five-segmented, armature (proximal to distal) as follows: one stout seta, four stout setae plus one large serrated, curving (prehensile) claw, three slender setae, two short setae plus two well developed denticulatedclaws, two large stout setae and 12 slender setae plus one aesthete. Second antenna(Figure 4E) five-segmented, prehensile. Basal segment stout (not shown), secondsegment with stout spiniform process, third segment bearing rectangular cutici.jlar flaps,two slender setae arising from large, curving spinous process. Fourth segment elongate and unarmed; fifth segment an unciform terminal claw bearing two slender setaeand one stout auxiliary spine nearly reaching the end of the claw. Mouth tubesiphonostome and similar to that of other species. Mandible (Figure 4F) of two parts,dentiferous margin with seven teeth. First maxilla (Figure 4G) biramous; endopodbearing two apical setae; exopod longer surmounted by two stout setae and one longerseta. Second maxilla (Figure 4H) brachiform, lacertus larger than brachium armed withcuticular flaps, brachium with crescent-shaped cuticular flaps and two tufts of setae(one coarse and one fine) at base of terminal claw (calamus). Claw bearing three distal rows of serrated membranes and one proximal serrated membranous flap.Maxilliped (Figure 41) chelate, indistinctly segmented, proximal segment pedunculate(omitted in illustration); corpus maxillipedis robust bearing small stout spine on distalmargin, rectangular cuticular flaps and a large transverse cuticular flange; myxal areaexpanded into large receptacle to accommodate claw of opposable segment. Shaftwith two setae: one near midpoint on lateral convex margin and the other adjacent to astrip of membrane along concave distal margin. Claw unciform with quadrangular cuticular expansion producing lateral shield.First four pairs of legs biramous with three-segmented rami and two-segmentedsympods. All basipods with lateral slender seta; first basipod bears additional distomedial slender seta. Ventral surfaces of all four legs bearing crescent shaped cuticularflaps. Armature of rami as follows: (non-pinnate setae in Roman numerals, pinnatesetae (bearing setules) in Arabic numerals).31Leg one Exopod 1-0 1-0 IV Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure 5A) all setae denticulated. Exopod two (Figure 5B) typicallymodified without cuticular flaps, first segment greatly enlarged bearing one smoothseta, second segment smaller with huge stout spine, third segment compressed apically armed with one stout seta, one truncate seta and one recurving slender seta. Legtwo endopod (Figure 5C) with naked proximal segment, segments two and three withcuticular flaps and two finely spinulated setae on apical segment. Legs three and four(Figure 5D) similar; endopodal seta denticulated, exopodal setae curving with branching tips (Figure 5E). Leg five (Figure 5F) oval; lateral surface covered with rectangularcuticular flaps, distally bearing three long slender setae plus one similar seta arisingdorsally from the base.Male: Not obtained (see Kabata, 1979)Comments: E. acuta appears to be specific to the angeishark Squat/na squat/na. Kabata (1979) mentions this parasite has been recorded (Valle, 1880; Brian, 1906;Oorde-de-Lint and Schuurmans Stekhoven, 1936) from the spiny dogfish Squalusacanthias, but neither he nor I have ever seen this copepod on that host (hundreds ofwhich I have examined) suggesting a suspect association.The geographical distribution of Squat/na squat/na ranges from southernNorway, Sweden and Shetland Island to Morocco off the western Sahara, CanaryIslands, and the Mediterranean (Compagno, 1984a). Predictably, the copepod hasbeen reported from most of this range.Additionally, Kabata (1979) has tentatively synonymized E. complexa (Brian,1924) with E. acuta. Besides similarities between descriptions of the two species, bothare found on the same host in the same area. Hence, the records of E. complexa (=E.acuta) from the host genera Torpedo, Pteromylaeus, Raja, and Myliobatis reported byEssafi and Raibaut (1977) from the Mediterannean will be treated as uncertain hostassociations.This species is easily distinguished by the nature of the caudal ramus, the huge,stout spine on the second segment of the modified exopod of leg two, and the branching, digitiform claw-like setae on the exopods of legs three and four.32Eudactylina aphiloxenos sp. nov.(Figures 6-7)Material examined. Numerous females from the branchial lamellae of the Pacificangelshark Squatina californica Ayres, 1859 from the southern California bight. Femaleholotype (USNM 266519) and 7 female paratypes (USNM 266520) deposited at theUnited States National Museum of Natural History.Etymology : The specific name aphiloxenos is derived from the greek aphilo, forunwanted or hateful and from the greek xenos for guest. Thus, the unwanted guest.DescriptionFemale (Figure 6A)Overall length in lateral view approximately 2.2 mm. Cephalothorax longer thanwide, lateral margin notched near base of maxilliped and lacertus of second maxillae.Ventrolateral and dorsal surfaces of cephalothorax bearing small triangular cuticularflaps. Tergum of first free thoracic somite with small triangular cuticular flaps on dorsalsurface. Second and third free thoracic somites with triangular cuticular flaps on thedorsal surface and distinct terga. Fourth free thoracic somite smaller than previous two,with distinct tergum and triangular cuticular flaps, bearing leg five. Genital segmentsmaller than preceeding somite, with cuticular flaps on ventral surface. Abdomen two-segmented, ventral surface bearing cuticular flaps. Caudal ramus (Figure 6B) slightlylonger than wide, bearing two stout terminal setae, one naked dorsal seta, and one lateral naked seta; ventral surface armed with posteriorly directed triangular cuticularflaps.First antenna (Figure 6C) indistinctly five-segmented, armature (proximal to distal) as follows: one stout seta; six smooth slender setae, two denticulated setae (oneshort (ghosted in near lateral margin), one long) plus one large serrated, curving (prehensile) claw; four slender setae plus one stout bilaterally denticulated seta; two shortsetae plus two well developed denticulated spines; 14 slender setae, one unilaterallydenticulated seta plus one aesthete. Second antenna (Figure 6D) five-segmented, prehensile. Basal segment stout, second segment with stout spiniform process, third segment bearing triangular cuticular flaps, two slender setae arising near base of largestyliform process. Fourth segment elongate with small cuticular flaps along convexmargin; fifth segment an unciform terminal claw bearing two slender setae and onestout auxiliary spine. Mouth tube siphonostome and similar to that of other species.33Mandible (Figure 6E) of two parts, dentiferous margin with seven teeth. Firèt maxilla(Figure 6F) biramous; endopod bearing two apical denticulated setae; exopod longersurmounted by two stout setae and one longer denticulated seta. Second maxilla(Figure 6G) brachiform, lacertus slightly larger than brachium armed with triangularcuticular flaps, brachium with triangular cuticular flaps and two tufts of setae and possibly a small reduced spine at base of terminal claw (calamus). Medial surface of clawbearing three distal rows of serrated membranes and one proximal serrated membranous flap, lateral surface only armed with two serrated membranous flaps. Maxilliped(Figure 6H) chelate, indistinctly segmented, proximal segment pedunculate (omitted inillustration); corpus maxillipedis robust bearing small stout spine on distal margin, triangular cuticular flaps; myxal area expanded into large receptacle to accommodate clawof opposable segment. Shaft with two setae: one near midpoint on lateral convex margin and the other adjacent to a strip of membrane along concave distal margin. Clawunciform with transverse cuticular flange bearing quadrangular cuticular expansion producing lateral shield.First four pairs of legs biramous with three-segmented rami and two-segmentedsympods. All basipods with lateral slender seta; first basipod bears additional distomedial slender seta. Ventral surfaces of all four legs bearing triangular cuticular flaps.Armature of rami as follows:Leg one Exopod I-C I-C IV Endopod 0-0 0-0 IILeg two (modified) Exopod I-C I-C Ill Endopod 0-0 0-0 IILeg three Exopod 1-C 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 1Leg one (Figure7A) all setae (except most medial seta on terminal segment ofexopod) denticulated. Exopod two (Figure 7B) typically modified without cuticularflaps, first segment greatly enlarged bearing one smooth seta, second segment smallerwith slender seta, third segment compressed apically armed with one short seta, onetruncate seta and one recurving slender seta. Leg two endopod (Figure 7B) with twofinely denticulated slender setae (one long, one short) on apical segment. Legs threeand four (Figure 7C) similar; endopodal seta denticulated, exopodal setae curving withbranching tips (Figure 7C detail). Leg five (Figure 7D) elongate; lateral surface coveredwith triangular cuticular flaps, distally bearing three long slender setae plus one setaarising dorsally from the base.Male: Not found34Comments: E. aphiloxenos appears to be specific to the Pacific angeisharkSquat/na californica.Squatina californica ranges from southeastern Alaska to the Gulf of California(Compagno, 1984a). Interestingly, Kato, Springer and Wagner (1967) synonomizedthe southern angelote Squat/na armata (Philippi, 1887) from off the eastern SouthPacific shores of South America with this host species. Compagno (1984a) mentionsthere is evidence against this taxonomic interpretation and adds that the Gulf ofCalifornica angelshark may in fact be different from the Pacific angelshark. Evidence insupport of Compagno’s position is added here with parasite data. The southernangelote originally Squat/na armata is parasitized by Eudactyl/na tuberifera Castro andBaeza (1987) from off the West coast of Chile, a species unmistakeably distinct (andredescribed later herein) from the new species infecting Squat/na californ/ca.E. aph/loxenos is similar to E. acuta and E. tuber/fera, both parasites ofangelsharks. All three species possess relatively large (almost digitiform) branchingtips on the setae of exopods three and four. E. aphiloxenous can be distinguished fromits other two allies by its relatively elongate fifth leg, the relatively small and slenderseta on the second segment of the modified second exopod, its very small and numerous triangular-shaped cuticular flaps, and its lack of the transverse cuticular flange onthe corpus of the maxilliped.Eudactylinaaspera Heller, 1865(Figures 8-9)Material exam/ned. One female, BMNH 1968.1.5.3 from the branchial lamellaeof the brownbanded bamboo shark, Chiloscyllium punctatum Muller and Henle, 1838collected from Moreton Bay, Queensland. Several females USNM 153636 from thebranchial lamellae of the milk shark, Rhizopr/onodon acutus (Ruppel, 1837), severalfemales USNM 153634 from the spinner shark, Carcharhinus brev/pinna (Muller andHenle, 1839), (=Carcharh/nus maculipinn/s (Poey, 1865)), and numerous femalesUSNM 153639 from the scalloped hammerhead, Sphyrna lewini (Griffith and Smith,1834), all collected from the Indian Ocean near Nosy Be, Madagascar.Descr/pt/onFemale (Figure 8A)Overall length in lateral view approximately 1.5 mm. Cephalothorax longer than35wide, lateral margin notched accomodating lacertus of second maxillae. Ventrolateraland dorsal surfaces of cephalothorax covered with cuticular flaps. Tergum of first, second, third, and fourth free thoracic somites covered with cuticular flaps. Fourth free thoracic somite smaller than previous three, bearing leg five. Genital segment smaller thanpreceeding somite, with cuticular flaps on ventral surface. Abdomen two-segmented,ventral surface bearing cuticular flaps. Caudal ramus (Figure 8B) longer than wide,bearing two stout setae, one dorsal naked seta, and one lateral naked seta; ventral surface armed with posteriorly directed cuticular flaps.First antenna (Figure 8C) five-segmented, armature (proximal to distal) as follows: one slender seta; seven smooth slender setae, one small denticulated seta plusone large denticulated, curving (prehensile) claw; seven smooth setae, one large spineplus one well developed denticulated spine; one large denticulated spine; terminal segment with 12 smooth slender setae, two denticulated setae plus one aesthete. Secondantenna (Figure 8D) five-segmented, prehensile. Basal segment short and unarmed,second segment with well developed spiniform process and triangular cuticular flaps,third segment bearing wavy quadrangular cuticular flaps, two slender setae arising fromlarge, curving spinous process. Fourth segment elongate and unarmed; fifth.segmentan unciform terminal claw bearing two slender setae and one stout auxiliary spine.Mouth tube siphonostome and similar to that of other species. Mandible (Figure BE) oftwo parts, dentiferous margin with six teeth. First maxilla (Figure BE) biramous; endopod bearing triangular cuticular flaps and two apical denticulated setae; exopod longersurmounted by two small setae and one longer denticulated seta. Second maxilla(Figure 8G) brachiform, lacertus larger than brachium armed with cuticular flaps (omitted in illustration), brachium with crescent-shaped cuticular flaps and two tufts of setae(one coarse or rope-like (possibly fused setae) and one fine or hair-like) at base of terminal claw (calamus). Claw bearing one serrated membrane parallelling the distal halfof the claw and two pendulous strips of membrane, one hanging from each side.Maxilliped (Figure 8H) chelate, indistinctly segmented, proximal segment pedunculate;corpus maxillipedis robust bearing small stout spine on distal margin, narrow rectangular cuticular flaps and a large transverse cuticular flange; myxal area expanded intolarge receptacle to accommodate claw of opposable segment. Shaft bearing many finetriangular cuticular flaps with two setae: one near midpoint on lateral convex marginand the other adjacent to a strip of membrane along concave distal margin. Claw unciform with quadrangular cuticular expansion producing lateral shield.First four pairs of legs biramous with three-segmented rami and two-segmentedsympods. All basipods with lateral slender seta; first basipod bears additional distomedial seta. Ventral surfaces of all four legs bearing crescent to sub-triangular shaped36cuticular flaps. Armature of rami as follows:Leg one Exopod 0-0 0-0 IV Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure 9A) all setae slender and denticulated. Exopod two (Figure 9C)typically modified, first segment greatly enlarged with proximal crescentic cuticular flappatch, one distal stout seta, second segment smaller with stout seta, third segmentarmed with one small sub-apical seta, one apical slightly curving seta plus one largeserrated curving claw-like seta. Leg two endopod (Figure 9B) completely covered withcrescentic and sub-triangular cuticular flaps with two finely denticulated slender setaeon terminal segment. Legs three and four (Figures 9D and 9E) similar; endopodal seta(Figure 9D) claw-like and unilaterally denticulated with a single setule or flagelliformprocess arising midpoint on the seta, exopodal setae (Figure 9E) stout with largestmost apical seta curving with bifid tip. Leg five (Figure 9F) longer than wide; lateral surface covered with crescent shaped cuticular flaps, distally bearing three long bifurcateslender setae plus one seta arising dorsally from the base.Male: UnknownComments: E. aspera was originally reported from Carcharias pleurotaenia,Bleeker, 1852 (=Carcharhinus limbatus (Valenciennes, 1839)), the blacktip shark fromJava (Heller, 1865). Since then this parasite has been reported from the branchiallamellae of the sharpnose shark, Rhizoprionodon terraenovae, (Richardson, 1836), thesmooth tooth or fine tooth shark Aprionodon isodon (=Carcharhinus isodon(Valenciennes, 1839)), collected from Lemon Bay, Florida (Gulf of Mexico) (Bere, 1936).Cressey (1967) reported E. aspera from the spinner shark, Carcharhinus brevipinna(Muller and Henle, 1839), the scalloped hammerhead, Sphyrna lewini (Griffith andSmith, 1834), and from Rhizoprionodon acutus (ROppel, 1837) all collected from theIndian Ocean near Nosy Be, Madagascar. Kabata (1970) added to the host list anunidentified requiem shark, Carcharhinus sp., and a member of the Hemiscyliidae, thebrownbanded bamboo shark, Chiloscyllium punctatum Muller and Henle, 1838 bothfrom Moreton Bay, Queensland. Finally, Essafi and Raibaut (1977) collected the parasite from the spinner shark from Tunisian waters. The parasite seems to have an affinity for hosts of the family Carcharhinidae, with only the one record from the Sphyrnidae37and one record from the Hemiscyliidae, an orectolobid (carpet sharks) as the hostgroup exceptions.Heller (1865) shows pointed processes arising from the lateral margins of thecephalothorax. This appears to be an erroneous interpretation of the notches in the lateral margins of the dorsal shield.This species is easily distinguished by the large spatulate process on the secondsegment of the second antenna, the pendulous membranous flaps on the claw of thesecond maxilla, the elongate proximal segment and large denticulated claw-like setaon the distal segment of the second exopod, and the branching setae of leg five.Eudactylina chilensis Ho and McKinney, 1981(Figures 10-11)Material examined. Several females, from the personal collections of Dr. JuShey Ho, California State University, Long Beach and Raul Castro Romero,Universidad de Antofagasta, Antofagasta, Chile, all specimens collected from thebranchial lamellae of the black shark or hooktooth dogfish, Aculeola nigra De Buen,1959 collected from Coquimbo, Chile (eastern South Pacific).DescriptionFemale (Figure 1 OA)Overall length in lateral view approximately 2.3 mm. Cephalothorax longer thanwide, lateral margin notched accomodating area of lacertus of second maxillae.Ventrolateral and dorsal surfaces of cephalothorax bearing small crescentic cuticularflaps. Tergum of first, second, and third free thoracic somites covered with small cuticular flaps on dorsal surface. Fourth free thoracic somite not as densely covered withflaps and smaller than previous somites and bearing leg five. Genital segment smallerthan preceeding somite, with cuticular flaps on ventral surface. Abdomen two-segmented, ventral surface bearing cuticular flaps. Caudal ramus (Figure lOB) longer thanwide, distal margin bearing three large clenticulated setae and one small smooth stoutseta, dorsal surface with one smooth slender seta, ventral surface armed with triangularshaped posteriorly directed cuticular flaps and one tiny seta.First antenna (Figure 1OC) five-segmented, armature (proximal to distal) as follows: first segment with one unilaterally denticulated seta, second segment with sixsmooth slender setae, one thickspine, one unilaterally denticulated seta plus one largedenticulated curving (prehensile) claw, third segment with nine smooth setae plus one38well developed unilaterally denticulated seta, fourth segment bearing one unilaterallydenticulated seta, fifth segment with one unilaterally denticulated seta, 13 slender setaeplus one aesthete. Second antenna (Figure 1OD) five-segmented, prehensile. Basalsegment short, second segment with sub-triangular cuticular flaps, third segment bearing rectangular cuticular flaps, two slender setae arising near base of spinous process.Fourth segment elongate with small triangular cuticular flaps; fifth segment an unciformterminal claw bearing two slender setae and one stout auxiliary spine. Mouth tubesiphonostome and similar to that of other species. Mandible (Figure 1 OE) of two parts,dentiferous margin with eight teeth. First maxilla (Figure 1 OF) biramous; endopod withtriangular cuticular flaps and bearing two apical spinulated setae; exopod longer surmounted by two stout setae and one longer slender seta. Second maxilla (Figure 1 OG)brachiform, lacertus larger than brachium armed with crescent shaped cuticular flaps,basal process located at base of lacertus, brachium with crescent-shaped cuticularflaps and two tufts of setae, one tuft composed of tine hair-like setules the other consisting of coarse rope-like, possibly fused setules at base of terminal claw (calamus).Claw bilaterally bearing two strips of serrated membranes. Maxilliped (Figure 1CH)chelate, indistinctly segmented, proximal segment pedunculate (omitted in illustration);corpus maxillipedis robust bearing small stout spine on distal margin, rectangular andsemicircular cuticular flaps; myxal area expanded into large receptacle to accommodate claw of opposable segment. Shaft bearing triangular cuticular flapswith twosetae: one near midpoint on lateral convex margin and the other along concave distalmargin. Claw unciform with quadrangular cuticular expansion producing lateral shield.First four pairs of legs biramous with three-segmented rami and two-segmentedsympods. All basipods with lateral slender seta; first basipod bears additional distomedial slender seta. Ventral surfaces of all four legs bearing sub-triangular shaped cuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 Ill Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure hA) all setae on rami slender and denticulated. Exopod two(Figure 11 B) typically modified generally devoid of cuticular flaps, first segment greatlyenlarged proximally bearing small patch of cuticular flaps and distally bearing onesmooth, slender seta, second segment smaller with slender seta, third segment armedwith two small curving seta and one large bilaterally denticulated curving seta. Leg two39endopod (Figurel 1 B) with two finely denticulated slender setae on apical segment.Legs three and four similar; exopod three and four (Figure 11C) with stout setae andone large bilaterally denticulated seta on terminal segment, endopod three and four(Figure liD) bearing a single bilaterally denticulated seta on terminal segment. Legfive (Figure 11 E) oval; lateral surface covered with fine triangular cuticular flaps, distallybearing three slender setae plus one seta arising dorsally from the base.Male: Not obtained (see Ho and McKinney, 1981)Comments: This parasite has not been reported since its initial discovery onAculeola nigra (Dalatiiformes: Etmopteridae) from Chilean waters by Ho and McKinney(1981).This species can be distinguished by the prescence of cuticular flaps on the second, third, and fourth segments of the second antenna with the reduced spiniformprocess on the third segment, the three apical slender, bilaterally, denticulated setaeplus the unique, tiny lateral seta on the caudal ramusEudactylina corrugata Bere, 1930(Figures 12-13)Material examined. One female, USNM 60469 from the branchial lamellae of thelittle skate, Raja erinacea Mitchell collected from St. Andrews, New Brunswick, onefemale, USNM 79619 from the branchial lamellae of Raja erinacea collected fromWoods Hole, Massachusetts July 17, 1914.DescriptionFemale (Figure 12A)Overall length in lateral view approximately 1.7 mm. Specimen unnaturallybloated due to lactic acid absorption during microscopic examination. Cephalothoraxlonger than wide, lateral margin notched accomodating lacertus of second maxillae.Ventrolateral and dorsal surfaces of cephalothorax covered with cuticular flaps. Terga offirst, second, third, and fourth free thoracic somites sparsely covered with cuticularflaps; terga of third and fourth free thoracic somites indistinct. Second and third freethoracic somites bearing posteriorly directed cuticular flaps on ventral surface. Fourthfree thoracic somite smaller than previous three, bearing leg five. Genital segmentsmaller than preceeding somite,with cuticular flaps on ventral surface. Abdomen two40segmented, ventral surface bearing cuticular flaps. Egg string (Figure 12B) uniseriate.Caudal ramus (Figure 12C) suboval, bearing two terminal slightly curved stout setae,one medial naked seta, and one lateral naked seta; ventral surface armed with posteriorly directed cuticular flaps.First antenna (Figure 1 2D) indistinctly five-segmented, armature (proximal to distal) as follows: first segment bearing one slender seta; second segment with sevensmooth setae, one denticulated seta plus one large denticulated, curving (prehensile)claw; third segment with nine smooth setae plus one large uncinate spine; fourth segment with one slender seta; terminal segment with 1 4 smooth setae plus one aesthete.Second antenna (Figure 12E) five-segmented, prehensile. Basal segment short, second segment with stout spiniform process, third segment bearing quadrangular cuticularflaps, two slender setae arising from near base of large curving spinous process.Fourth segment elongate and unarmed; fifth segment an unciform terminal claw bearingtwo slender setae and one stout auxiliary spine. Mouth tube siphonostome and similarto that of other species. Mandible (not illustrated) of two parts, dentiferous margin witheight teeth. First maxilla (Figure 1 2F) biramous; endopod bearing two apical spinulated setae; exopod longer surmounted by two small slender setae and one longer spinulated seta. Second maxilla (Figure 12G) brachiform, lacertus larger than brachium,brachium with sub-triangular and crescent-shaped cuticular flaps and two tufts of setae(one coarse or rope-like (possibly fused setae) and one fine or hair-like) at base of terminal claw (calamus). Claw bearing two pairs of serrated membranes parallelling theclaw plus one distal strip of membrane along the convex margin. Maxilliped (Figure12H) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearing small stout spine on distal margin, narrow rectangular cuticularflaps and region of small triangular flaps; myxal area expanded into large receptacle toaccommodate claw of opposable segment. Shaft bearing two setae: one near midpointon lateral convex margin and the other adjacent to a strip of membrane along concavedistal margin. Claw unciform with quadrangular cuticular expansion producing lateralshield.First four pairs of legs biramous with two-segmented endopods, three-segmented exopods and two-segmented sympods. All basipods with lateral slender seta; firstbasipod bears additional distomedial slender seta. Ventral surfaces of all four legsbearing rectangular to sub-triangular shaped cuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 1-0 IV Endopod 0-0 - IILeg two (modified) Exopod 1-0 1-0 Ill Endopod 0-0 - II41Leg three Exopod 1-0 1-0 III Endopod 0-0 -Leg four Exopod 1-0 1-0 III Endopod 0-0 - ILeg one (Figurel3A) exopod indistinctly three-segmented; exopodal setae slender unilaterally denticulated with or without spinules, endopodal setae bilaterally spinulated. Exopod two (Figure 13B) typically modified, first segment greatly enlarged withproximal triangular cuticular flaps along the medial margin, one distal stout seta, secondsegment smaller with stout spine, third segment armed with one small sub-apical seta,another sub-apical recurving slender seta plus one large, blunt apical truncate seta. Legtwo endopod (Figure 1 3C) with two finely spinulated slender setae on terminal segment. Legs three and four (Figure 13D) similar; setae slender and denticulated. Legfive (Figurel3E) longer than wide; lateral surface covered with rectangular cuticularflaps, distally bearing three slender setae plus one seta arising dorsally from the base.Male: UnknownComments: E. corrugatato has only been reported by Bere (1930) occurring onthe skates Raja erinacea Mitchell, 1825 collected from St. Andrews, New Brunswickand Woods Hole, Massachusetts and from Raja scabrata Garman, 1913 (=Raja radiataDonovan, 1807) collected from Woods Hole, Massachusetts.This species is easily distinguished by the large truncate seta on the terminalsegment of the second exopod and by the two-segmented endopods of legs onethrough four.Eudactylina dactylocerca sp. nov.(Figures 14-15)Material examined. Several females from the branchial lamellae of the shovel-nose guitarfish Rhinobatus productus (Ayres) collected from inshore waters from thesouthern California Bight. Female holotype (USNM 266521) and 4 female paratypes(USNM 266522) deposited at the United States National Museum of Natural History.Etymology: The specific name dactylocerca is derived from the Greek dactylos meaning finger or digit and cerco from kerkos meaning tail, referring to the digitiform. processes on the caudal rami.42DescriptionFemale (Figure 1 4A)Overall length in lateral view approximately 1.9 mm. Cephalothorax longer thanwide, lateral margin notched accomodating lacertus of second maxillae. Anterolateraland dorsal surfaces of cephalothorax covered with cuticular flaps. Dorsal and ventrolateral surfaces of tergum of first, second, and third free thoracic somites covered withcuticular flaps; terga of first and second free thoracic somites aliform. Fourth free thoracic somite smaller than previous three, bearing leg five. Genital segment smaller thanpreceeding somite. Abdomen (Figure 14C) two-segmented, ventral surface bearing apair of blunt tubercles on each segment, and a pair of semicircular cuticular flaps on theposterior segment. Egg string (Figure 14D) uniseriate. Caudal ramus (Figure 14B)beautifully modified into a tridentate digitiform structure composed of three stronglysclerotized tuberculous processes (fused modified setae?), one tiny proximal seta (sensilla?), one dorsomedial slender seta, one small stout ventral seta plus two ventrodistalslender setae; ventral surface armed with a single posteriorly directed semicircularcuticular flap.First antenna (Figure 14E) five-segmented, armature (proximal to distal) as follows: first segment bearing one slender seta; second segment with four smooth slender setae, one large smooth seta, three denticulated slender setae plus one large denticulated, curving (prehensile) claw; third segment with eight smooth setae, one denticulated slender seta plus one large uncinate denticulated spine; fourth segment withone slender seta and an atypical conical process; terminal segment with 13 smoothspiniform plus one aesthete. Second antenna (Figure 14F) five-segmented, prehensile. Basal segment short, second segment with unciform process and truncated quadrangular cuticular flaps, third segment bearing quadrangular cuticular flaps and twoslender setae arising from near base of well produced spinous process. Fourth segment elongate and unarmed; fifth segment an unciform terminal claw bearing two slender setae and one stout uncinate auxiliary spine. Mouth tube siphonostome and similarto that of other species. Mandible (Figure 14G) of two parts, dentiferous margin withfive teeth. First maxilla (Figure 1 4G) biramous; endopod bearing tiny triangular cuticular flaps and two apical denticulated setae; exopod longer surmounted by two smallsetae and one longer slender seta. Second maxilla (Figure 14H) brachiform, lacertuslarger than brachium, brachium with crescent-shaped cuticular flaps and two tufts ofsetae (one coarse or rope-like (possibly fused setae) and one fine or hair-like) at baseof terminal claw (calamus). Claw bearing two rows of serrated membranes parallellingthe claw plus one distal pendulous strip of membrane along the convex margin of otherside. Maxilliped (Figure 141) chelate, indistinctly segmented, proximal segment pedun43culate; corpus maxillipedis robust bearing small seta on distal margin and narrow rectangular cuticular flaps; myxal area expanded into large receptacle to accommodateclaw of opposable segment. Shaft bearing two setae: one with enlarged proximalregion near midpoint on lateral convex margin and the other adjacent to a strip of membrane along concave distal margin. Claw (Figure 14J) complex, unciform with tiny proximal seta, cuticular expansions producing a fused complex of claw and cuticle.First four pairs of legs biramous, except leg four with two-segmented endopod,three-segmented exopods and endopods on remaining rami, sympods two-segmented.All basipods with lateral slender seta; first basipod bears additional distomedial slenderseta. Ventral surfaces of all four legs bearing rectangular to sub-triangular shapedcuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 1-0 Ill Endopod 0-0 0-0 IILeg two (modilied) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 Ill Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 Ill Endopod 0-0Leg one (Figurel5A) rami three-segmented; exopodal setae unilaterally bearingserrated flange with medial denticulations on largest apical seta on terminal segment,largest endopodal seta unilaterally bearing serrated flange, smaller bilaterally denticulated. Exopod two (Figure 1 5B) typically modified, first segment greatly enlarged withquadrangular cuticular flaps along the lateral margin, one distal seta, second segmentsmaller with seta, third segment armed with two smooth curving setae plus one largecurving bilaterally denticulated seta. Leg two endopod (Figure 1 5B) with one slenderseta and one large bilaterally serrated seta on terminal segment. Sclerite bar betweenleg two and leg three (Figure 150) with single, large medial stylet. Legs three and four(Figure 15D) similar; except leg four has a two-segmented endopod; exopodal setaeclaw-like and unilaterally denticulated, endopodal seta unilaterally bearing denticles andserrated membranous flange. Leg five (Figurel5E) slightly longer than wide; lateralsurface smooth, distally bearing three pinnate setae plus one seta arising dorsally fromthe base.Male: UnknownComments: E. dactylocerca is specific to the shovelnose guitarfish Rhinobatusproductus. It is the third eudactylinid to be reported from this genus of host.Eudactylina rhinobati Raibaut and Essafi, 1979 has been found from Rhinobatus rhino44batus (Linne’, 1758), and from Rhinobatus cern/cu/us (Geoffrey Saint-Hilaire, 1817) collected from Tunisia, and recently Luque and Farfan (1991) acquired Eudactylina peruensis from Rhinobatus planiceps Garman, 1880 from eastern South Pacific waters offthe west coast of Peru.Some of the illustrations of E. rhinobati (Raibaut and Essafi, 1979) lack detail butimply something atypical, yet vaguely similar (digitiform elements) among the caudalrami of these three rhinobatid-infesting species. All three species share the dorsolateral aliform expansions of free thoracic somites one and two, suggesting a very closerelationship between these species despite the great geographical distances that separate them.This species is easily distinguished from all other species in the genus by themodified caudal rami. The interesting fine denticulations along the lateral margin of thesetae on exopods three and four are shared by E. peruensis.Eudactylina diabolophi!a sp. nov.(Figures 16-17)Material examined. Two females from the branchial lamellae of the Manta orDevil Ray Manta birostris (Donndorff, 1798), (California Academy of Sciences FishCollection) collected August 20, 1951 during the George Vanderbilt Equatorial PacificExpedition from station 49 located at 5 51.9’ N X 162 7.6’ N, near Sand and LineIslands. Female holotype (USNM 266523) deposited at the United States NationalMuseum of Natural History.Etymology: The specific name diabolophi/a is derived from the Greek diabolos meaning devil and phil/as meaning loving, referring to this species predilection for feedingupon the devil ray.DescriptionFemale (Figure 16A)Overall length in lateral view approximately 3.8 mm. Cephalothorax longer thanwide, lateral margin notched. Anterolateral and dorsal surfaces of cephalothorax covered with cuticular flaps. Dorsolateral surfaces of first, and second free thoracic somitescovered with cuticular flaps. Fourth free thoracic somite smaller than previous three,bearing leg five. Genital segment smaller than preceeding somite. Abdomen two-segmented; lateral surface of posterior segment with cuticular flaps. Caudal ramus (Figure451 6B) atypically elongate with six distal, relatively unmodified naked setae, a distal areaof anteriorly directed rectangular flaps and the lateral margin armed with subtriangularcuticular flaps.First antenna (Figure 16C) six-segmented, armature (proximal to distal) as follows: first segment atypically bearing a lateral patch of semicircular cuticular flaps andbearing one reduced stout seta; second segment with five naked and one large denticulated, curving (prehensile) claw; third segment with three naked setae; fourth segment with three small naked seta plus one large styliform seta, fifth segment with a single naked seta; terminal segment with 13 setae plus one aesthete. Second antenna(Figure 16D) five-segmented, prehensile. Basal segment short, second segment elongate and unarmed, third segment bearing thin rectangular cuticular flaps and two slender setae arising from near base of greatly reduced spinous process (this may only bethe distomedial corner of this segment). Fourth segment elongate with fine triangularcuticular flaps along convex margin; fifth segment an elongate, unciform terminal clawbearing two slender setae and one small auxiliary spine. Mouth tube siphonostomeand similar to that of other species. Mandible (Figure 1 6E) of two parts, dentiferousmargin with five teeth. First maxilla (Figure 1 6F) biramous; sympod with three rows offine triangular cuticular flaps, endopod bearing tiny triangular cuticular flaps and twostout apical setae; exopod longer with tiny triangular cuticular flaps and surmounted bytwo small stout setae and one longer seta. Second maxilla (Figure 14G) brachiform,lacertus larger than brachium bearing small triangular cuticular flaps and basal process,brachium with triangular cuticular flaps and two tufts of setae (one coarse or rope-like(possibly fused setae)) and one fine or hair-like) at base of terminal claw (calamus).Claw bearing two rows of denticles proximally plus a row of denticles along both theconcave and convex margins. Maxilliped (Figure 16H) chelate, indistinctly segmented,proximal segment pedunculate; corpus maxillipedis robust bearing small naked seta ondistal margin and tiny triangular cuticular flaps; myxal area proximally bearing triangularcuticular flaps and expanded into a receptacle to accommodate claw of opposable segment. Shaft with proximal patch of small triangular flaps and bearing two setae: onevery small near midpoint (not illustrated) on lateral convex margin and the other alongconcave distal margin. Claw (Figure 16H) complex, unciform with a very small lateralshield.First four pairs of legs biramous and trimerite, sympods two-segmented. Allbasipods with lateral slender seta; first basipod bears additional distomedial slenderseta. Ventral surfaces of all four legs bearing triangular shaped cuticular flaps.Armature of rami as follows:46Leg one Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg two Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figurel7A) rami three-segmented; exopodal setae unilaterally to bilaterally denticulated, largest endopodal seta bilaterally denticulated, smaller smooth. Legtwo (Figure 17C) atypically unmodified, setae stout with and without denticulations.Legs three and four (Figure 17B) similar; distolateral areas on first and second segments of exopods greatly extending past segmental boundaries, with ventral facedevoid of cuticular flaps, largest of three stout setae on terminal segment bilaterallydenticulated. Leg five (Figurel7D) subquadrate, slightly wider than long, distally bearing three slender setae plus one similar seta arising dorsally from the base; lateral surface with small triangular cuticular flapsMale: UnknownComments: E. diabolophila is the first record of Eudactylina from the genusManta. Although Pacific and Atlantic mantas are presently considered conspecific, itwould be of interest to examine this host from the Atlantic for additional corroborativeevidence.This species is easily distinguished from all other species in the genus by thegreatly extended distolateral regions of the first and second segments on the third andfourth exopods, the unusually elongate caudal rami, the very large strongly curved clawof the second antenna, and the greatly reduced “lateral shield” of the claw of the maxilliped. The unmodified condition of the exopod of leg two found in this species is similarly found in E. acanthii and E. squamosa.Eudactylina doilfusi Brian, 1924(Figures 18-19)Syn: Eudactylina spinifera Wilson, 1932, syn nov.Eudactylina spinifera Wilson, 1932; of Bere (1936)Eudactylina spinifera Wilson, 1932; of Yamaguti (1963)Eudactylina spinifera Wilson, 1932; of Cressey (1970)47Material examined. Several females (types?) MNHN CP 174 from the branchialIamellae of the host squale (Marao); Several female specimens USNM 63915 from thebranchial lamellae of Carcharias commersoni (= ?) collected from Wood’s Hole, July25, 1927; female “holotype” USNM 56621 from gills of Carcharhinus milberti; fromWood’s Hole; numerous females USNM 153650, 153651, 153652, 63915, 79087 fromthe gills of Carcharhinus milberti (Valenciennes, j.. Muller and Henle, 1839),(=Carcharhinus plumbeus (Nardo, 1827)).DescriptionFemale (Figure 18A)Overall length in lateral view approximately 1.8 mm. Cephalothorax longer thanwide, lateral margin notched accomodating lacertus of second maxillae. Anterolateraland dorsal surfaces of cephalothorax sparsely covered with spiniform cuticular flaps.Dorsal and ventrolateral surfaces of terga of first, second, third, and fourth free thoracicsomites sparsely covered with spiniform cuticular flaps. Fourth free thoracic somitesmaller than previous three, bearing leg five. Genital segment smaller than pr.eceedingsomite and sparsely covered with spiniform cuticular flaps. Abdomen (Figures 18A, B)two-segmented, ventral surface bearing a pair of slender setae on anterior segment,and posteriorly directed triangular cuticular flaps on both segments. Caudal ramus(Figure 1 8B) longer than wide with posteriorly directed triangular cuticular flaps on ventral surface, rami bearing one lateral and one medial seta, distally one stout unilaterallydenticulated seta, two terminal finely denticulated or spinulated seta and possibly onetiny unilaterally denticulated or spinulated seta.First antenna (Figure 18C) indistinctly five-segmented, armature (proximal todistal) as follows: first segment bearing one short seta; second segment with eightsmooth stout setae of various sizes, plus one large denticulated, curving (prehensile)claw; third segment with nine smooth stout setae; fourth segment with one stout seta;terminal segment with 14 smooth slender setae plus one aesthete. Second antenna(Figure 1BD) five-segmented, prehensile. Basal segment short, second segmentnaked, third segment bearing six small semicircular cuticular flaps and two slendersetae arising from near base of well produced spinous process. Fourth segment elongate and unarmed; fifth segment an unciform terminal claw bearing two slender setae,one very small stout seta, and one stout uncinate auxiliary spine. Mouth tube siphonostome and similar to that of other species. Mandible (Figure 1 8E) of two parts, dentiferous margin with five teeth. First maxilla (Figure 18F) biramous; endopod bearing tinytriangular cuticular flaps, one apical denticulated seta, and one smooth with papilliformtip; exopod longer surmounted by two small setae and one longer slender seta all48tipped with tiny setule. Second maxilla (Figure 18G) brachiform, lacertus larger thanbrachium with triangular cuticular flaps, brachium with triangular-shaped cuticular flapsand two tufts of setae (one coarse or rope-like (possibly fused setae) and one fine orhair-like) at base of terminal claw (calamus). Claw bearing two rows of serrated membranes parallelling the claw plus six claw-like denticles along the concave distal surface. Maxilliped (Figure 18H) chelate, indistinctly segmented, proximal segmentpedunculate (not illustrated); corpus maxillipedis robust apparently devoid of typicalsmall spiniform seta on distal margin, two patches of triangular cuticular flaps; myxalarea expanded into large receptacle to accommodate claw of opposable segment.Shaft bearing two setae: one small slender seta near midpoint on lateral convex marginand the other adjacent to a strip of membrane along concave distal margin. Claw complex, unciform with tiny membrane or membranous flange along concave margin.First four pairs of legs biramous and trimerite except for two-segmented endopodof leg one and the endopod of leg four fused into a large claw, sympods two-segmented. All basipods with lateral slender seta; first basipod bears additional distomedialslender seta. Ventral surfaces of all four legs bearing small triangular shaped cuticularflaps. Armature of rami as follows:Leg one Exopod 1-0 1-0 Ill Endopod 0-0 - IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0Leg one (Figurel 9A) rami three-segmented; exopodal setae bearing bilaterallyor unilaterally serrated membranous flange, denticulations on medial edge of largestapical seta on terminal segment, largest endopodal seta bilaterally denticulated, smallerseta smooth. Leg two (Figure 1 9B) with exopod typically modified, first segment greatly enlarged with proximal patch of triangular cuticular flaps, distally bearing one naked,seta, second segment smaller with naked seta, third segment armed with two stoutsetae each bearing a single denticle, plus one smaller naked seta. Leg two endopod(Figure 19B) with one slender seta and one large bilaterally spinulated seta on terminalsegment. Leg three (Figure 19C) exopodal setae stout and unilaterally denticulated,largest seta on terminal segment bilaterally denticulated; endopodal seta stout andbilaterally denticulated. Leg four (Figure 19D) exopod similar to leg three but withsmooth setae except for large bilaterally denticulated on terminal segment, endopodmodified into a heavily sclerotized, fused unciform claw with a proximal patch of cuticular flaps. Leg five (Figure 1 9E) slightly longer than wide; lateral surface with few cuticu49lar flaps, distally bearing three spiniform setae plus one seta arising dorsally from thebase.Male: UnknownComments: E. dolifusi Brian, 1924 was originally reported from the gills of a shark(squale (Marao)) collected from Mauritius. It was later discovered on the branchiallamellae of the brown or sandbar shark, Carcharhinus milberti (Valenciennes, in Mullerand Henle, 1839), (=Carcharhinus plumbeus (Nardo, 1827)) from the Wood’s Holeregion but was described as a new species, E. spinifera by Wilson (1932). Bere (1936)reported E. spinifera from the dusky shark C. obscurus (LeSueur, 1818). Yamaguti(1963) transferred the errors into his compilation, and finally Cressey (1970) reportedWilson’s E. spinifera from the sandbar shark, C. plumbeus and the blacknose shark C.acronotus (LeSueur, 1818).Examination of several specimens confirms E. spinifera Wilson, 1932 is a juniorsynonym of E. dolifusi Brian, 1924.Eudactylina dolifusi seems to be specific to the few aforementioned species ofsharks of the Carcharhinidae, with a preference for the sandbar shark Carcharhinusplumbeus.This species is readily identified by the huge, modified claw-like fused endopodof leg four.Eudactylina epaktolampter sp. nov.(Figures 20-23)Material examined. Two females and one male from the branchial lamel!ae of thesmooth lanternshark Etmopterus pusillus (Lowe, 1839), (California Academy ofSciences, CAS 1967 Vll:6) collected from off the Mississippi Delta, August 24, 1962 onthe R/V Oregon, station 3724, located 2904’N X 8831; and two females from the gillsof E. pusillus (USNM 220344) collected from Atlantic Liberia at a depth of 400 m, station location 0628’N X 10257’W . Female holotype (USNM 266524) deposited at theUnited States National Museum of Natural History.Etymology: The specific name epaktolampteris derived from the Greek epakter meaning hunter and lampter meaning lantern, referring to the predilection of this parasite for50lantern sharks.DescriptionFemale (Figure 20A)Overall length in lateral view approximately 3.1 mm. Cephalothorax longer thanwide, lateral margin notched. Surface of cephalothorax, first, second, and third freethoracic somites covered with cuticular flaps. Fourth free thoracic somite smaller thanprevious three, bearing leg five. Genital segment slightly smaller than preceedingsomite. Abdomen two-segmented; ventrodistal surface of posterior segment with cuticular flaps. Caudal ramus (Figure 20B) with three stout setae, one very tiny setule, plustwo elongate slender setae (one medial, one lateral).First antenna (Figure 20C) five-segmented, armature (proximal to distal) as follows: first segment bearing one stout seta; second segment with seven slender setae,one large stout seta, and one large smooth, curving (prehensile) claw; thir&segmentwith ten slender setae; fourth segment with one long slender seta; terminal segmentwith 14 slender setae plus one aesthete. Second antenna (Figure 20D) five-segmented, prehensile. Basal segment short, second segment elongate and unarmed, thirdsegment bearing proximally directed triangular cuticular flaps and two slender setae,segment apparently devoid of typical spinous process. Fourth segment elongate andunarmed; fifth segment an elongate, unciform terminal claw bearing two slender setaeand one small auxiliary spine. Mouth tube siphonostome and similar to that of otherspecies. Mandible (Figure 20E) of two parts, dentiferous margin with seven teeth. Firstmaxilla (Figure 20F) biramous; endopod bearing tiny triangular cuticular flaps and twostout apical setae, one unilaterally denticulated and one with proximal patch of spinules;exopod longer with tiny triangular cuticular flaps and surmounted by two small stoutsetae (one omitted in illustration) and one longer seta. Second maxilla (Figure2OG)brachiform, lacertus larger than brachium bearing semicircular cuticular flaps, brachiumwith semicircircular cuticular flaps and two tufts of setae (one coarse or rope-like (possibly fused setae) and one fine or hair-like) at base of terminal claw (calamUs). Clawatypically bearing a patch or bibbed patch of fine spinulations along concave surface.Maxilliped (Figure 20H) chelate, indistinctly segmented, proximal segment pedunculate(not shown); corpus maxillipedis robust bearing small spiniform seta on distal marginand small rectangular cuticular flaps; myxal area expanded into a receptacle to accommodate claw of opposable segment. Shaft bearing two setae: one near midpoint andthe other along concave distal margin near membranous strip (see detail). Claw(Figure 20H detail) complex, unciform with a large orbicular lateral shield51First leg biramous and bimerite, legs two, three and four biramous and trimerite,sympods two-segmented. All basipods with lateral slender seta; first basipod bearsadditional distomedial slender seta. Ventral surfaces of all four legs bearing semicircular cuticular flaps. Armature of rami as follows:Leg one Exopod I-C - IV Endopod 0-0 - IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 lii Endopod 0-0 0-0 ILeg one (Figure 21A) rami two-segmented (possibly indistinctly three); exopodaland endopodal setae bilaterally denticulated. Leg two exopod (Figure 21B) typicallymodified, first segment greatly elongated with proximal patch of flaps, all setae smoothand stout, endopod (Figure 21C) tipped with two slender setae. Legs three and four(Figure 21D) similar; all setae smooth and stout except bilaterally denticulated middleseta on terminal segment of exopod. Leg five (Figure2l E) subquadrate, longer thanwide distally bearing three slender setae plus one similar seta arising dorsally from thebase; lateral surface with small triangular cuticular flaps.Male: (Figure 22A)Overall length in lateral view approximately 1 .8 mm. Similar to female, exceptabdomen four-segmented, leg five and leg six arising from genital complex. Caudalramus (Figure 22B) bearing four pinnate setae and two smooth slender setae.First antenna (Figure 22C) indistinctly of nine segments; armature (proximal todistal) as follows: first segment bearing one stout seta, second segment with nine slender setae plus one large curving (prehensile) claw, third segment armed with four slender setae, fourth segment with two setae, fifth segment with one seta, sixth segmentwith four slender setae, seventh segment armed with two setae, eighth segment bearing a single small stout seta and long aesthete, ninth segment bearing 12 slendersetae. Maxilliped (Figure 22D) subchelate; corpus bearing many small rectangularcuticular flaps, myxal area bearing a well produced styliform process, subchela bearingtwo stout setae, claw produced into a large curving process proximally producing a bifidspine which in concert with the claw creates a concavity for the myxal process to actupon.First pair of legs (Figures 23A and 23B) biramous and bimerite, legs two, threeand, four biramous and trimerite. Sympods two-segmented. Semicircular cuticular flapson ventral surfaces of legs I - IV. Armature of rami as follows:52Leg one Exopod 1-0 - V Endopod 0-0 - IILeg two Exopod I-I I-I VII Endopod 0-0 0-I IIILeg three Exopod I-I I-I VII Endopod 0-I 0-I IVLeg four Exopod I-I I-I VII Endopod 0-0 0-0 IIIExopod one (Figure 23A) two-segmented; first segment with single smooth seta,second segment bearing two long pinnate setae plus three smaller naked setae.Endopod one (Figure 23B) tipped with two naked setae. Leg two (Figure 23C) exopodalsetae predominately pinnate medially and smooth and along lateral margin, proximalsegment of endopod with large scierotized lateral process, remaining setae pinnate.Leg three (Figure 23D) exopodal and endopodal setae smooth along lateral margin,pinnate along medial margin. Leg four similar to leg three except for terminal segmentof endopod (Figure 23E) bearing only three instead of four setae. Leg five (Figure 23F)armed with three slender setae on distal edge and one pinnate seta at base. Leg six(Figure 23G) consists of three slender naked setae on distal edge of finely spinulatedlobe.Comments: E. epaktolampter is the first record of Eudactyilna from the genusEtmopterus. Both of my finds come from the smooth lanternshark, Etmopterus pusillus(Lowe, 1839), collected in the Gulf of Mexico off the Mississippi Delta and off theLiberian Atlantic.The male of this species exhibits a very unusual blunt spinous process on thelateral margin of the basal segment of the second endopod. This character has onlybeen reported once before from the entire order Siphonostomatoida, predictably fromanother male eudactylinid, Eudactylina chi/ensis Ho and McKinney, 1981 from The blackshark Aculeola nigra De Buen, 1959.This shared derived character indicates a closephylogenetic relationship between these species of parasites. Interestingly, both hostshave been removed from the family Squalidae and recently placed in a common familyEtmopteridae. The parasites support this systematic restructuring.This species is easily distinguished from all other congeners by the spinulationscovering the concave surface of the second maxilla, the minute apicomedial seta on thecaudal rami, the large orbicular lateral shield on the claw of the maxilliped. Theabsence of the spiniform process on the third segment of the second antenna is sharedby E. acanthii, E. diabolophi/a, E. insolens, E. Iongispina, E. oliveri, E. pollex, and E.vaquetillae, all strikingly different from this species in a multitude of characteristics.53Eudactylina hornbostell sp. nov.(Figures 24-25)Material examined. Several females from the branchial lamellae of the bat rayMyliobatis sp., captured from waters off Nosy Be’, Madagascar. Donated from the personal collection of Dr. Roger Cressey, National Museum of Natural History, SmithsonianInstitution, Washington, D.C. Female holotype (USNM 266525) and 5 female paratypes(USNM 266526) deposited at the United States National Museum of Natural History.Etymology: The specific name hornbosteli is in honor of Mr. Bernard HornBostel for computer hardware support for this effort.DescriptionFemale (Figure 24A)Overall length in lateral view approximately 1.6 mm. Cephalothorax longer thanwide, lateral margin slightly concave. Surface of cephalothorax, first, second, thirdand, fourth free thoracic somites covered with wavy cuticular flaps. Fourth free thoracicsomite, genital segment and, two-segmented abdomen all bearing wavy cuticular flapson ventral surface. Caudal ramus (Figure 24B) with two stout curving setae, plus twoelongate slender setae (one dorsal, one lateral).First antenna (Figure 24C) apparently four-segmented, armature (pràximal todistal) as follows: first segment bearing one tiny seta; second segment with four smallsetae, three elongate blunt setae and one large denticulated, curving (prehensile) claw;third segment with seven slender setae plus two large denticulated spines; fourth segment an elongate process with 14 setae of various shapes and sizes plus one aesthete.Second antenna (Figure 24D) five-segmented, prehensile. Basal segment short, second segment elongate with a very long, proximally directed spiniform process, thirdsegment elongate bearing proximally directed wavy rectangular cuticular flaps and twoslender setae arising from near base of long curving spiniform process. Fourth segment elongate and unarmed; fifth segment an elongate, unciform terminal claw bearingtwo slender setae and one extremely elongate auxiliary spine. Mouth tube siphonostome and similar to that of other species. Mandible (Figure 24E) of two parts, dentiferous margin with five teeth. First maxilla (Figure 24F) biramous; endopod more robustbearing two slender apical setae, one unilaterally denticulated and one smooth; exopodlonger and surmounted by two small stout setae and one longer slender seta. Secondmaxilla (Figure 24G) brachiform, lacertus larger than brachium bearing wavy cuticularflaps, brachium with wavy cuticular flaps (some triangular), distal patch of triangular54prickles two tufts of setae (one coarse or rope-like (possibly fused setae), one fine orhair-like (omitted in illustration)) at base of terminal claw (calamus). Claw bearing fourstrips of serrated membrane plus one serrated strip on other side. Maxilliped (Figure24H) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearing small seta on distal margin and large wavy cuticular flaps; myxalarea expanded into a receptacle to accommodate claw of opposable segment. Shaftwith long membranous flange, bearing two setae: one elongate near midpoint and theother along concave distal margin near membranous strip (see detail). Claw (Figure20H detail) complex, unciform with a large orbicular lateral shield.First four pairs of legs biramous and trimerite, sympods two-segmented. Allbasipods with lateral pinnate slender seta; first basipod bears additional distomedialslender seta. Ventral surfaces of legs two, three, and four bearing wavy cuticular flaps.Armature of rami as follows:Leg one Exopod 1-0 1-0 IV Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure 25A) with single row of fine triangular cuticular flaps fringing distal margins of all segments except terminal segment of exopod; lateral exopodal setaeunilaterally bearing serrated membranous flange, apical setae smooth and slender,endopoda! setae naked and slender. Leg two exopod (Figure 25B) typically modified,first segment greatly enlarged with stout seta, second segment swollen with stout seta,terminal segment with two small slender setae plus one truncate seta, endopod (Figure25B) tipped with two slender setae. Legs three and four (Figure 25C) similar; lateralmargins of endopodal segments one and two with fringes of fine setae, all exopoda)setae stout bearing large subapical tines, endopod tipped by single finely spinulatedseta. Leg five (Figure25D) longer than wide; lateral surface with wavy cuticülar flapsand distally bearing three semipinnate slender setae plus one pinnate seta arising dorsally from the base.Male: UnknownComments: E. hornbosteli is easily distinguished from its congeners by theextremely elongate setae on the second, third and fourth segments of the first antenna,the extremely elongate and spiniform apical segment of the first antenna, the elongated55segments of the second antenna, the very long, curving claw and auxiliary spine on thesecond antenna, the elongate spiniform process found on the second segment of thesecond antenna, the large digitiform subapical tines found on the setae of exopodsthree and four, and the fringe of spinules or cuticular flaps along the distomedial margins of the exopodal and endopodal segments of leg one.Eudactylina indivisa Castro and Baeza, 1991(Figures 26-27)Material examined. Several females from the branchial lamellae of the easternSouth Pacific bat ray, Myliobatis peruvianus (Garman, 1913) coflected fromAntofagasta, Chile. Donated from the personal collection of Mr. Raul Castro Romero,Universidad de Antofagasta, Chile.DescriptionFemale (Figure 26A)Overall length in lateral view approximately 1.8 mm. Cephalothorax longer thanwide, lateral margin notched accomodating lacertus of second maxillae. Surface ofcephalothorax covered with cuticular flaps. Terga of first, second, third, and fourth freethoracic somites covered with cuticular flaps. Fourth free thoracic somite, genital segment and abdomen bearing posteriorly directed cuticular flaps on ventral surface.Fourth free thoracic somite smaller than previous three, bearing leg five. Genital segment smaller than preceeding somite. Abdomen two-segmented. Caudal ramus(Figure 26B) longer than wide, bearing two distal apically curved stout setae, one dorsalslender seta, one lateral slender seta, and one proximal setule; ventral surface armedwith posteriorly directed cuticular flaps.First antenna (Figure 260) apparently four-segmented, armature (proximal todistal) as follows: first segment bearing one slender seta; second segment with foursmall setae, one stout seta, one slender denticulated seta, one long slender seta, plusone large denticulated, curving (prehensile) claw; third segment bearing eight slendernaked setae plus one large spine armed with rectangular flaps; terminal segment with14 smooth spiniform setae plus one aesthete. Second antenna (Figure 26D) five-segmented, prehensile. Basal segment short, second segment with spiniform process,third segment bearing six rectangular cuticular flaps, two slender setae arising fromnear base of elongate styliform process. Fourth segment elongate and unarmed; fifth56segment an unciform terminal claw bearing two slender setae and one elongate auxiliary spine. Mouth tube siphonostome and similar to that of other species. Mandible(Figure 26E) of two parts, dentiferous margin with seven teeth. First maxilla (Figure26F) biramous; endopod with tiny triangular cuticular flaps and bearing two apical bilaterally denticulated setae; exopod longer surmounted by two small setae and onelonger seta. Second maxilla (Figure 26G) brachiform, lacertus larger than brachiumbearing large round rectangular cuticular flaps, brachium with wavy, rectangular, andsemicircular cuticular flaps, a distal patch of triangular prickles and two tufts of setae(one coarse or rope-like (possibly fused setae) and one fine or hair-like)) at base of terminal claw (calamus). Claw bearing four strips of serrated membranes parallelling thedistal portion of the claw plus one proximal strip of membrane along the convex margin,two strips present on other side. Maxilliped (Figure 26H) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearing small stout spineon distal margin, narrow wavy, rectangular cuticular flaps; myxal area expanded intolarge receptacle to accommodate claw of opposable segment. Shaft bearing two setae:one near midpoint on lateral convex margin and the other adjacent to a stripof membrane along concave distal margin. Claw unciform with quadrangular cuticular expansion with thinner cuticular expansion on distal edge producing lateral shield.First four pairs of legs biramous and trimerite, two-segmented sympods. Allbasipods with lateral slender seta; first basipod bears additional distomedial slenderseta. Ventral surfaces of all four legs bearing various shaped cuticular flaps. Armatureof rami as follows:Leg one Exopod 1-0 1-0 IV Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 Ill Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure 27A) lateral exopodal setae unilaterally bearing serrated membranous flange, apical setae slender with small setules (spinules), endopodal setaebilaterally spinulated. Exopod two (Figures 27B and 27C) modified, first segmentgreatly enlarged with a few tiny triangular cuticular flaps along the medial margin, onedistal denticulated seta, second segment smaller with large, stout spine, third segmentarmed with one small subapical seta, another subapical recurving seta plus one bluntapical truncate seta. Leg two endopod (Figure 27B) with subtriangular expansion in distolateral corner of first segment, one small spinulated seta and one large bilaterallydenticulated seta on terminal segment. Legs three and four (Figures 27D and 27E)57similar; exopods three and four (Figure 27E) with denticulated setae, endopods threeand four (Figure 27D) tipped with a single bilaterally denticulated seta. Leg five (Figure27F) subtriangular, longer than wide, distally bearing three slender setae plus one pinnate seta arising dorsally from the base;lateral surface covered with triangular cuticularflaps. Leg six (Figure 27G) represented by threevery tiny spines located on the rim ofthe aperture of the oviducal opening.Male: UnknownComments: E. indivisa seems to be aparasite of temperate eastern SouthPacific bat rays. So far, it has been reported from the gills of Myliobatis peruvianus(Garman, 1913) and Myliobatis chilensis Phillipi, 1892, from near Antofagasta, Chile.The unusual presence of cuticular flapson the large spine on the third segmentof the first antenna, the difficult to characterize claw of the maxilliped, and thelongstraight, denticulated spine-like seta on the second segment of exopod two are readydiscriminants for this species.Eudactylina insolens Scott and Scott, 1913(Figures 28-29)Material examined. Several females(BMNH 1913.9.18.292-293) from thebranchial lamellae of the tope shark, Galeorhinus galeus (Linnaeus, 1758) collectedfrom the Irish Sea.DescriptionFemale (Figure 28A)Overall length in lateral view approximately 1.8 mm. Cephalothorax longer thanwide, lateral margin notched accommodating lacertus of second maxillae. Anterolateralsurface of cephalothorax covered with cuticular flaps. Terga of first, second, third, andfourth free thoracic somites atypically devoid of cuticular flaps. Genital segment andabdomen bearing posteriorly directed cuticular flaps on ventral surface. Fourth free thoracic somite bearing leg five. Genitalsegment smaller than preceeding somite.Abdomen two-segmented. Caudal ramus(Figure 28B) longer than wide, bearing threeterminal denticulated setae, one dorsomedial seta, and one lateral naked seta;ventralsurface armed with posteriorly directed triangular cuticular flaps.First antenna (Figure 28C) five-segmented, armature (proximal to distal) as fol58lows: first segment bearing one spiniform seta; second segment with six smooth setae,two unilaterally denticulated spiniform setae plus one large denticulated, curving (prehensile) claw; third segment bearing nine smooth setae; fourth segment bearing a single seta. Terminal segment atypically exhibiting the presence of cuticular flaps, andarmed with 13 smooth slender setae plus one aesthete. Second antenna (Figure 28D)five-segmented, prehensile. Basal segment short, second segmentwith triangularcuticular flaps, third segment bearing three rectangular cuticular flaps,two slendersetae arising from near base of reduced spiniform process. Fourth segment elongateand unarmed; fifth segment an unciform terminal claw bearing two slender setae andone tiny seta near auxiliary spine. Mouth tube siphonostome and similar to that ofother species. Mandible (Figure 28E) of two parts, dentiferous margin with six teeth.First maxilla (Figure 28F) biramous; endopod with tiny triangular cuticular flaps, bearing one apical bilaterally denticulated seta, and one smooth seta; exopod longer surmounted by two small setae and one longer seta. Second maxilla (Figure 28G) brachiform, lacertus subequal to brachium bearing large triangular cuticularflaps, brachiumwith triangular cuticular flaps, and one tuft of setae at base of terminalclaw (calamus).Claw bearing two rows of denticles parallelling the concave margin. Maxilliped (Figure28H) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearing small stout spine on distal margin, and tinytriangular cuticularflaps; myxal area expanded into large receptacle to accommodate claw of opposablesegment. Shaft bearing two setae: one near midpoint on lateral convex margin and theother adjacent to a strip of membrane along concave distal margin. Claw unciform withovoid cuticular expansion producing lateral shield.First four pairs of legs biramous and trimerite except two-segmentedexopod andthe fused to partially fused endopod of leg one, two-segmented sympods. All basipodswith lateral slender seta; first basipod bears additional distomedial slender seta. Ventralsurfaces of all four legs bearing triangular shaped cuticular flaps except for thin rectangular flaps found on the basal segment of modified exopod two. Armature of rami asfollows:Leg one Exopod 1-0 1-0 III Endopod 0-0 -IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0ILeg one (Figure 29A) exopodal setae spiniform, bilaterally bearing serratedmembranous flange, smaller endopodal seta bilaterally spinulated,larger unilaterally59bearing denticles. Exopod two (Figure 29B) modified, first segment greatly enlargedwith many thin rectangular cuticular flaps and one distal curving seta, second segmentsmaller with distally extending lateral lobe bearing single curved seta, thirdsegmentarmed with three curved setae. Leg two endopod (Figure 29C) with one small spinulated seta and one large bilaterally spinulated seta on terminal segment. Legsthree andfour (Figures 29D) similar; exopods three and four with smooth styliform setae,endopods three and four tipped with a single unilaterally denticulated seta.Leg five(Figure 29E) ovoid, barely longer than wide; lateral surface covered with triangularcuticular flaps, distally bearing three slender setae plus one similar seta arising dorsallyfrom the base.Male: UnknownComments: E. insolens seems to be a rarely reported parasite of temperateeastern North Atlantic and Mediterranean sharks. So far, it has been reported from thegills of the tope shark, Galeorhinus galeus (Linnaeus, 1758) collected from the Irish Sea(Scott and Scott, 1913), and off Norfolk in the North Sea (Hamond, 1969). Essafi andRaibaut (1977) have found this parasitic copepod on the gills of the smooth-houndMustelus mustelus (Lin naeus, 1758), the blackspotted smooth-hound Mustelusmediterraneus Quignard and Capape, 1972 (=Mustelus punctulatus Risso, 1826), andthe starry smooth-hound Mustelus asterias Cloquet, 1821 all collected in theMediterranean Sea near Tunis.It should be noted that the genera this copepod parasitizes, Galeorhinus andMustelus are members of the carcharhiniform family Triakidae.The unusual absence of cuticular flaps on the dorsal surfaces of the cephalothorax and free thoracic somites one through four coupled with the distally extended lobeof the second segment of the modified second endopod and denticulated claw of thesecond maxilla help to identify this copepod.Eudactylina longispina Bere, 1936(Figures 30-31)Material examined. One holotype female (USNM 69839) from the branchialIamellae of the bonnethead shark, Sphyrna tiburo (Linnaeus, 1758) collected fromLemon Bay, Florida in the Gulf of Mexico, and one female (USNM 153653) from the60same species of host from Tampa Bay, Florida.DescriptionFemale (Figure 30A)Overall length in lateral view approximately 1.1 mm. Cephalothorax longer thanwide, lateral margin notched accomodating lacertus of second maxillae. Lateral surfaceof cephalothorax covered with cuticular flaps. Cuticular flaps restricted to lateral surfaces of first and second free thoracic somites. Third and fourth free thoracic somitesatypically devoid of cuticular flaps. Fourth free thoracic somite bearing leg five. Genitalsegment and abdomen bearing posteriorly directed cuticular flaps on ventral surface.Genital segment smaller than preceeding somite. Abdomen two-segmented. Caudalramus (Figure 30B) longer than wide, bearing three terminal slender setae, one dorsomedial slender seta, and one lateral slender seta; ventral surface armed with posteriorlydirected triangular cuticular flaps.First antenna (Figure 30C) five-segmented, armature (proximal to distal) as follows: first segment bearing one small stout seta; second segment with eight smoothstout setae, plus one curving (prehensile) claw; third segment bearing seven smoothsetae; fourth segment bearing a single seta. Terminal segment armed with 14 smoothslender setae plus one aesthete. Second antenna (Figure 30D) five-segmented, prehensile. Basal segment short, second segment naked, third segment devoid of cuticular flaps, two slender setae arising from distal margin. Fourth segment elongate andunarmed; fifth segment an unciform terminal claw bearing two slender setae and oneelongate auxiliary spine. Mouth tube siphonostome and similar to that of other species.Mandible (Figure 30E) of two parts, dentiferous margin with six teeth. First maxilla(Figure 30E) biramous; endopod bearing two slender setae, exopod longer surmounted by two small setae and one longer seta. Second maxilla (Figure 30F) brachiform,lacertus subequal to brachium bearing elongate, triangular cuticular flaps, brachiumwith long, triangular cuticular flaps, and one tuft of setae at base of terminal claw (calamus). Claw bearing two rows of denticles parallelling the concave margin. Maxilliped(Figure 30G) chelate, indistinctly segmented, proximal segment pedunculate; corpusmaxillipedis robust bearing small stout spine on distal margin, and large triangular cuticular flaps; myxal area expanded into large receptacle to accommodate claw of opposable segment. Shaft bearing two setae: one near midpoint on lateral convex marginand the other adjacent to a strip of membrane along concave distal margin. Claw unciform with ovoid cuticular expansion producing lateral shield.First four pairs of legs biramous and trimerite except two-segmented endopod ofleg two, two-segmented sympods. All basipods with lateral slender seta; first basipod61bears additional distomedial stout seta. Ventral surfaces of all four legs bearing triangular shaped cuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 1-0 Ill Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 - IILeg three Exopod 1-0 1-0 Ill Endopod 0-0 0-0 0-0Leg four Exopod 1-0 1-0 III Endopod 0-0 0-0 0-0Leg one (Figure 31A) exopodal setae smooth and blunt, endopodal setae slender, largest seta denticulated, smallest seta smooth. Exopod two (Figure 31 B) typicallymodified, first segment greatly enlarged with proximal patch of large triangular cuticularflaps and one distal curved seta, second segmentsmaller bearing single curved seta,third segment armed with three curved setae, one armed with a single setule. Leg twoendopod (Figure 31C) with two smooth slender setae. Legs three and four similar;sympods and exopods three and four (Figure 31 D) with denticulated styliform setae,terminal segment of endopods three and four (Figure 31E)modified into a long bluntscierotized process, patch of large triangular cuticular flaps on basal segment. Leg five(Figure 31 F) longer than wide, distally bearing three slendersetae plus one similar seta(not illustrated) arising dorsally from the base; lateral surface sparsely covered with triangular cuticular flaps.Male: UnknownComments: E. longispina was reported originally by Bere (1936), and later byPearse (1952) and Cressey (1970) from the gills of thebonnethead shark Sphyrnatiburo (Linnaeus, 1758). All collections were from the West coast of Florida in the Gulfof Mexico.The bizarrely modified terminal segment on theendopod of legs three and fourforming a long, blunt process is unique to this species.Eudactylina myliobatidos Luque and Farfan,1991(Figures 32-33)Material examined. One female (USNM 251 291) from the branchial larnellae ofthe bat ray Myliobatis chilensis Phillippi, 1892 collected from inshore waters near62Chorrillos, Peru.DescriptionFemale (Figures 32A)Overall length in lateral view approximately 1 .8 mm. Cephalothorax longer thanwide, lateral margin slightly notched accomodating lacertus of second maxiflae.Dorsolateral surface of cephalothorax covered with wavy cuticular flaps. Wavy cuticularflaps present on dorsolateral surfaces of first, second, third and fourth free thoracicsomites. Fourth free thoracic somite bearing leg five. Fourth free thoracic somite, genital segment, and abdomen bearing posteriorly directed cuticular flaps on ventral surface. Genital segment smaller than preceeding somite. Abdomen two-segmented.Caudal ramus (Figure 328) longer than wide, bearing two relatively elongate, apicallycurved terminal setae, one dorsal slender seta, and one lateral slender seta; ventralsurface armed with posteriorly directed triangular cuticular flaps.First antenna (Figure 32D) indistinctly four-segmented, armature (proximal todistal) as follows: first segment bearing one small seta; second segment with fivesmooth setae (one elongate, two minute, two stout), one small, unilaterally denticulated seta, plus one curving, denticulated (prehensile) claw; third segment bearing sixsmooth setae, plus two large distal auxiliary spines (one unilaterally bearing teeth andthe other with four semicircular cuticular flaps), Terminal segment armed with 11 slendersetae, one large stout seta, plus one aesthete. Second antenna (Figure 32D) five-segmented, prehensile. Basal segment short, second segment armed with spinousprocess, third segment bearing six rectangular cuticular flaps and two slender setaearising from base of well produced spinous process. Fourth segment elongate andunarmed; fifth segment an unciform terminal claw bearing a single slender seta and oneelongate auxiliary spine. Mouth tube siphonostome and similar to that of other species.Mandible (Figure 32E) of two (possibly three) parts, dentiferous margin with six teeth.First maxilla (Figure 32F) biramous; endopod bearing two setae, both unilaterally denticulated, exopod longer surmounted by two small naked setae and one longer, unilaterally denticulated seta. Second maxilla (Figure 32G) brachiform, lacertus larger thanbrachium bearing large, semicircular cuticular flaps, brachium with large slender, rectangular cuticular flaps, a distal patch of prickles, plus two tufts of setae (one coarse orrope-like (possibly fused setae) and one fine or hair-like) at base of terminal claw (calamus). Claw bearing four rows of serrated membranes distally, plus one longer serratedstrip proximally, two similar strips parallelling the concave margin present on other side.Maxilliped (Figure 32H) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust, typical small stout spine on distal margin not observed,63corpus with rectangular cuticular flaps; myxal area bearing large transverse cuticularflange and expanded into large receptacle to accommodate claw of opposable segment. Shaft bearing two setae: one near midpoint on lateral convex margin and theother adjacent to a strip of membrane along concave distal margin. Claw unciformbearing membranous flange with quadrate cuticularexpansion producing lateral shield(see detail).First four pairs of legs biramous and trimerite except for the two-segmentedendopod of the first leg, two-segmented sympods.All basipods with lateral slenderseta; first basipod bears additional distomedial slender seta. Ventral surfaces of all fourlegs bearing variously shaped cuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 1-0 IV Endopod 0-0 - IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-00-0 IILeg three Exopod 1-0 1-0 Ill Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure 33A) exopodal setae bearing lateral serrated membranousflange except for the two most distomedial setae(largest seta appears to bilaterallybear spinules or tiny denticles, smallest seta naked), endopodal setae bilaterally denticulated / spinulated. Exopod two (Figure 33B) modified, first segment greatly enlargedwith two thin, rectangular cuticular flaps and onedistal denticulated seta, second segment smaller bearing single stout seta, third segment armed with one small slenderseta, one slender recurving seta, and one truncate seta. Leg two endopod (Figure33C) with two slender setae, longest bilaterally bearing stoutsetules or minute denticlesand the other smooth. Legs three and four similar; exopods three and four (Figure33D) with denticulated styliform setae, terminal segment ofendopods three and four(Figure 33D) bearing single spinulated seta. Medial stylet (Figure 33E) stout and blunt,located between pedigers three and four and notdirectly arising from either somitesinterpodal bars. Leg five (Figure 33F) longer than wide; lateral surface sparsely covered with small triangular cuticular flaps, distally bearing three slender setae plus onepinnate seta arising dorsally from the base.Male: UnknownComments: This redescription of E. myliobatidosbrings attention to detail missing in the original description of this species (Luque and Farfan, 1991). This speciesshares the characters of a four-segmented first antenna, elongated segments of the64second antenna, and wavy cuticular flaps with E. hornbostell, E. mdivisa, and E. nykterimyzon all parasites of Myliobatis sp. from their respective waters.The large semicircular flaps and denticulations on the two large distal auxiliaryspines on the third segment of the first antenna, the denticulated seta on the proximalsegment of exopod two and the relatively elongate terminal setae on the caudal ramiare found in E. mdivisa, also a parasite of Myliobatis chilensis. Both E. mdivisa and E.myliobatidos are so similar to one another that synonymization may be warranted.Although, the two large rectangular cuticular flaps on the proximal segment of the modified second exopod separate this species from E. indivisa, additional collecting of theseparasites may show this trait not to be as taxonomically unique as this present effortsuggests.Eudactylina nykterimyzon sp. nov.(Figures 34-35)Material examined. Several females from the branchial lamellae of the bat rayMyiobatis californica Gill, collected from inshore waters near El Segundo, Californica;and several females from the same host species from Punta Arena de Ia Ventana, inthe southern Sea of Cortez (Gulf of California). Female holotype (USNM 266527) and7 female paratypes (USNM 266528) deposited at the United States National Museumof Natural History.Etymology: The specific name nykterimyzon is derived from the Greek nykteris meaning bat, and myzo meaning suck, referring to this species’ predilection for feeding uponbat rays.DescriptionFemale (Figures 34A and 34B)Overall length in lateral view approximately 2.0 mm. Cephalothorax longer thanwide, lateral margin notched accomodating lacertus of second maxillae. Dorsolateralsurface of cephalothorax covered with cuticular flaps. Cuticular flaps present on dorsolateral surfaces of first, second, third and fourth free thoracic somites. Fourth free thoracic somite bearing leg five. Fourth free thoracic somite, genital segment, andabdomen bearing posteriorly directed cuticular flaps on ventral surface. Genital segment smaller than preceeding somite. Abdomen two-segmented. Caudal ramus65(Figure 34C) longer than wide, bearing two terminal , apically curved setae, one dorsomedial slender seta, and one lateral slender seta; ventral surface armed with posteriorlydirected triangular cuticular flaps.First antenna (Figure 34D) indistinctly four-segmented, armature (proximal todistal) as follows: first segment bearing one naked seta; second segment with sevensetae (four small, three large), plus one curved, denticulated (prehensile) claw; thirdsegment bearing nine (six small, one elongate, and two large distally placed auxiliaryspines (setae)) setae, terminal segment armed with 14 setae plus one aesthete.Second antenna (Figure 34E) five-segmented, prehensile. Basal segment short, second segment armed with spiniform process, third segment bearing three cuticular flapsand two slender setae arising from base of well produced spiniform process. Fourthsegment elongate and unarmed; fifth segment an unciform terminal claw bearing twoslender setae and one elongate auxiliary spine. Mouth tube siphonostome and similarto that of other species. Mandible (Figure 34F) of two parts, dentiferous margin withsix teeth. First maxilla (Figure 34G) biramous; endopod bearing two slender setae,longer seta unilaterally denticulated, exopod longer surmounted by two small setae andone longer slender seta. Second maxilla (Figure 34H) brachiform, lacertus larger thanbrachium bearing large, wavy cuticular flaps, brachium with large wavy, and triangularcuticular flaps, a distal patch of prickles, possibly a small spine plus two tufts of setae(one coarse or rope-like (possibly fused setae) and one fine or hair-like) at base of terminal claw (calamus). Claw bearing three rows of serrated membranes distally, plusone longer serrated strip proximally, two similar strips parallelling the concave marginpresent on other side. Maxilliped (Figure 341) chelate, indistinctly segmented,. proximalsegment pedunculate; corpus maxillipedis robust bearing small stout spine on distalmargin, and large wavy cuticular flaps; myxal area expanded into large receptacle toaccommodate claw of opposable segment. Shaft bearing two setae: one near midpointon lateral convex margin and the other adjacent to a strip of membrane along concavedistal margin. Claw unciform bearing membranous flange with subquadrate cuticularexpansion producing lateral shield.First four pairs of legs biramous and trimerite, two-segmented sympods. Allbasipods with lateral slender seta; first basipod bears additional distomedial seta.Ventral surfaces of all four legs bearing variously shaped cuticular flaps. Armature oframi as follows:Leg one Exopod 1-0 1-0 IV Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 Ill Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 lii Endopod 0-0 0-0 I66Leg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure 35A) exopodal setae bearing lateral serrated membranousflange, endopodal setae bilaterally denticulated. Exopod two (Figure 35B) modifiedand devoid of cuticular flaps, first segment greatly enlarged with one distal seta, secondsegment smaller bearing single stout seta and conical protuberance, third segmentarmed with two small setae, and one truncate seta. Leg two endopod (Figure 35B) withtwo smooth setae. Legs three and four similar; exopods three and four (Figure 35C)with denticulated styliform setae, terminal segment of endopods three and four (Figure35C) bearing single denticulated seta. Leg five (Figure 35D) longer than wide, distallybearing three slender setae plus one seta arising dorsally from the base; lateral surfacesparsely covered with cuticular flaps.Male: UnknownComments: Eudactylina nykterimyzon seems to be specific to the California batray Myliobatis californica Gill, 1865.Other species possessing a distinctly 4-segmented first antenna are: E. hornbosteli, E. indivisa, E. myliobatidos, E. pristiophori, E. squamosa, E. turgipes, and E.urolophi. E. acuta, E. aphiloxenous, and E. tuberifera all possess an indistinctly 4- or5-segmented first antenna, as segments three and four show incomplete fusion. Six ofthe aforementioned species possess serrated membranes on the setae of the first exopod, these are: E. hornbosteli, E. indivisa, E. myliobatidos, E. pristiophori, E. turgipes,and E. urolophi. Five of these species possess only four setae on their caudal rami,they are: E. hornbosteli, E. mdivisa, E. myliobatidos, E. pristiophori, and E. urolophi.Only three of these species, E. hornbosteli, E. mdivisa, and E. myliobatidos possesselongate spiniform processes on segments two and three of the second antennae, asdoes E. nykterimyzon. E. nykterimyzon can be distinguished from this small group ofallies by being the only member with three cuticular flaps on segment three of the second antenna; the others all have six. The extremely elongate components of the second antenna of E. hornbosteli set that species apart from the rest of this group. Thepossession of a denticulated seta on the second segment of the second exopod andcuticular flaps on the auxiliary spine of E. mdivisa and E. myliobatidos additionally guarantee the uniqueness of this new species.67Eudactylina oliveri Lau bier, 1968(Figures 36-39)Syn: Eudactylina olivieri, of Pillai (1985)Material examined. Several females and males from the branchial lamellae ofthe spinetail mobula, Mobula japanica (Muller and Henle, 1841) collected from PuntaArena de Ia Ventana (Gulf of California), Mexico and from the same host species fromnear Anacapa Island (southern California Channel Islands); several females.from thesmoothtail mobula Mobula thurstoni (Lloyd, 1908) (=Mobula lucasana Beebe and Tee-Van, 1938) collected from Punta Arena de Ia Ventana, Mexico; several females fromMobula sp. collected from Nosy Be, Madagascar from the personal collection of Dr.Roger Cressey, Smithsonian Institution, Washington, D.C.DescriptionFemale (Figure 36A)Overall length in lateral view approximately 1 .9 mm. Cephalothorax longer thanwide, lateral margin notched accomodating lacertus of second maxillae. Lateral surfaces of cephalothorax covered with cuticular flaps. Cuticle of first, second, and thirdfree thoracic somites laterally covered with cuticular flaps. Fourth free thoracic somitesmaller than previous three with cuticular flaps on ventral surface and bearing leg five.Genital segment smaller than preceeding somite,with cuticular flaps on ventral surface.Abdomen two-segmented, ventral surface bearing cuticular flaps. Caudal ramus(Figure 36B) longer than wide, bearing four terminal small stout setae, one subterminalsmall stout seta, plus one dorsal slender seta; ventral surface covered with posteriorlydirected triangular cuticular flaps. Egg string (Figure 36C) uniseriate.First antenna (Figure 36E) six-segmented, armature (proximal to distal) as follows: first segment with triangular and rectangular cuticular flaps along lateral marginbearing one stout seta; second segment with eight naked setae of various sizes plusone large smooth, curving (prehensile) claw; third segment with four slender setae plusone small papilliform seta; fourth segment with two large seta, one small stout seta, andone large distal spine; fifth segment bearing one tiny seta, terminal segment with 14setae plus one aesthete. Second antenna (Figure 36F) five-segmented, prehensile.Basal segment short, second segment elongate bearing long rectangular cuticularflaps, third segment bearing rectangular cuticular flaps, two slender setae arising fromnear base of very reduced spinous process. Fourth segment elongate with many rectangular cuticular flaps (only two visible in illustrated view), fifth segment an elongate68unciform terminal claw bearing two slender setae and one long slender spine. Mouthtube (Figure 36D) siphonostome and similar to that of other species; labrum with sub-rectangular flaps, distal edge of frons labri bearing membrane; lateral surface of labiumwith elongate triangular cuticular flaps, ventrodistal surface with smali prickles.Mandible (Figure 36G) of two parts, dentiferous margin with six teeth. First maxilla(Figure 36H) biramous; sympod with small patches of spinules, endopod bearing twostout spinulated setae; exopod longer surmounted by two small naked setae and onelonger denticulated seta. Second maxilla (Figure 361) brachiform, lacertus larger thanbrachium, with small triangular cuticular flaps, brachium with rectangular and triangularcuticular flaps, a distal patch of prickles a tiny seta and a single tuft of fine setae at baseof terminal claw (calamus). Distal region of claw bearing two rows of denticles, proximal region with three pairs of serrated membranes. Maxilliped (Figure 37A) chelate,indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearing small stout spine on distal margin, small semicircular cuticular flaps and small triangular flaps; myxal area expanded into large receptacle to accommodate claw of opposable segment. Shaft bearing two setae: one near midpoint on lateral convex marginand the other adjacent to a strip of membrane along concave distal margin. Claw(Figure 37B) unciform with reduced quadrangular cuticular expansion producing a verysmall lateral shield.First four pairs of legs biramous with three-segmented endopods, three-segmented exopods and two-segmented sympods. All basipods with lateral seta,(basipods two, three and four with spatulate setae); first basipod bears additional distomedial seta. Ventral surfaces of all four legs bearing triangular and semicircular cuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 Ill Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 Ill Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 IExopodal setae of leg one (Figure 37C) small and denticulated on the most proximal two segments, endopodal setae unilaterally denticulated. Exopod two (Figure37D) somewhat modified, first segment elongate with a proximal patch of triangularcuticular flaps along lateral margin, one distal naked seta, second segment smaller withsmall, naked seta, third segment armed with two small sub-apical naked setae, plusone longer unilaterally denticulated (two teeth) seta. Leg two endopod (Figure 37D) with69two finely spinulated/denticulated setae on terminal segment. Setae of legs three andfour (Figure 37E) stout with largest endopodal and exopodal seta bearing well developed spinules. Leg five (Figure 37F) elongate distally bearing three spatulate setaeplus one seta arising dorsally from the base; lateral surface with rectangular and triangular cuticular flaps along ventral surface.Male: (Figure 38A)Overall length in lateral view approximately 1.6 mm. More slender than female,abdomen four-segmented, leg five arising from fourth free thoracic somite and leg sixarising from genital segment. Caudal ramus (Figure 38B) bearing four robust setae(three semipinnate), one dorsal pinnate seta and one small lateral naked seta.First antenna (Figure 38C) indistinctly eight- or nine-segmented; armature (proximal to distal) as follows: first segment bearing one small seta and triangular cuticularflaps along lateral margin, second segment with eleven slender setae plus one largecurving (prehensile) claw, third segment armed with nine slender setae, fourth segmentwith four distal setae and one proximal slender seta, fifth segment with two slendersetae, sixth segment with two slender setae, seventh segment armed with two setae,terminal segment bearing a single aesthete plus 13 slender setae of various heights.Second antenna (Figure 38D) five-segmented, prehensile; proximal segment short,second segment elongate with proximally directed rectangular cuticular flaps, third segment with proximally directed cuticular flaps and two slender setae arising from nearbase of small spiniform process, fourth segment elongate and naked, terminal segmentan elongate claw with one small auxiliary spine and two proximal slender setae.Mandible (Figure 38E) similar to that of female. First maxilla (Figure 38F) biramous;endopod bearing small triangular cuticular flaps and two apical setae, one smooth andone unilaterally denticulated; exopod with triangular cuticular flaps, two small setae andone long seta. Second maxilla (Figure 38G) similar to that of female. Maxilliped (Figure38H) subchelate; corpus bearing many small rectangular cuticular flaps, myxal areabearing a well produced denticulated, styliform process, shaft bearing two small slendersetae, claw produced into a large curved process proximally producing a robust spinealong the concave margin.First four pair of legs (Figures 39A-39E) biramous and trimerite. Sympods twosegmented. Variously shaped cuticular flaps on ventral surfaces of legs. Armature oframi as follows:Leg one Exopod 1-0 1-0 IV Endopod 0-0 0-0 IILeg two Exopod I-I I-I VI Endopod 0-I 0-I V70Leg three Exopod I-I I-I VII Endopod 0-I 0-I IVLeg four Exopod I-I I-I VII Endopod 0-I 0-I IIIExopod one (Figure 39A) three-segmented; first segment with single smoothseta, second segment bearing single short seta, terminal segment with four apicalnaked setae. Endopod one (Figure 39A) tipped with two short setae. Leg two (Figure39B) lateral exopodal setae with membranes along lateral margins, medial setae pinnate, lateralmost long seta semipinnate with membrane along lateral margin; endopodal setae pinnate. Exopod three and four (Figure 39C) with stout setae aloog lateralmargin and pinnate setae along medial margin. endopodal setae pinnate along medialmargin, apical setae naked. Terminal segment of endopod three (Figure 39D) with onenaked plus three pinnate setae. Terminal segment of endopod four (Figure 39E) withone naked and two pinnate setae. Leg five (Figure 39F) composed of three pinnatesetae on distal edge of leg with one similar seta at base. Leg six (Figure 39G) consistsof two pinnate setae on distal edge of small lobe.Comments: E. 0//yen was originally described by Laubier, 1968 from gills ofMobula mobu/ar (Bonnaterre, 1788) captured near Narbonne Beach, along the FrenchMediterrranean. The next record of this parasite was from gills of Mobula diabolusSmith, 1943 (=Mobula kuhili (Valenciennes in Muller and Henle, 1841)) from CapeComorin, India (Pillai, 1985). This redescription adds to the list Mobula japanica (MUllerand Henle, 1841) from the southern Sea of Cortez (Gulf of California) and from off theChannel Islands, southern California, Mobula thurstoni (Lloyd, 1908) (previously knownas M. lucasana Beebe and Tee-Van, 1938) from the southern Sea of Cortez and,Mobula sp. from Nosy Be, Madagascar.This host list is interesting in light of the recent revision of the genus Mobula byNotarbartolo-di-Sciara (1987) in which he mentions the possible synonymy of Mobulamobular and Mobula japanica and, the possibility of some records of M. kuhili being inerror and probably representing M. thurstoni. In absence of more reliable host idenetification one can speculate that E. oilyen may be specific only to the spine-tail mobula,Mobula japan/ca and the smooth-tail mobula, Mobula thurstoni.Recently, another new species, Eudactyilna mobuli was described by Hameedet al, (1990) from Mobula diabolus from off the coast of Kerala in the Indian Ocean. Thehideous cartoon-like abstractions used for illustrations add nothing but pain and confusion to the researcher from that literature. Key attributes such as the unique spatulatesetae found in E. oliveri are not shown or compared with features found on E. mobull.Hameed et al, (1990) claim their new species is morphologically similar to E. oliveri,71but differ by an unarmed claw of the second antenna (this does not occur anywhere inthe genus that I am aware of), and a two-segmented exopod on the first leg. The highlyabstracted illustrations of these characters coupled with the lack of so much detailmake these claims difficult to agree with. The general appearance of the illustrations(the elongate exopods of legs three and four resulting in an ant-like appearance) andthe possibility of the host being M. thurstoni, suggest to me that E. mobuli may be synonymous with E. oilyen.Eudactylina oilyen is easily distinguished from all other congeners by the spatulate spine-like setae located on the basipods of legs two, three, and four and onreduced leg live.Eudactylina papillosa Kabata, 1970(Figures 40-41)Material examined. One paratype female (BMNH 1968.1.5.2) from the branchiallamellae of the stingray, Dasyatus kuhil (Muller and Henle, 1838) collected fromMoreton Bay, Queensland, Australia.DescriptionFemale (Figure 40A)Overall length in lateral view approximately 1.3 mm. Cephalothorax longer thanwide, lateral margin slightly notched accommodating lacertus of second maxillae.Dorsolateral surfaces of cephalothorax covered with wavy cuticular flaps. Cuticle offirst, second, third and fourth free thoracic somites covered with cuticular flaps. Fourthfree thoracic somite smaller than previous three with cuticular flaps on ventral surfaceand bearing leg five. Genital segment smaller than preceeding somite,with cuticularflaps on ventral surface. Abdomen two-segmented, ventral surface bearing cuticularflaps. Caudal ramus (Figure 40B) longer than wide, bearing three stout terminal setae(one very small, two well produced) plus one dorsomedial slender seta and, one lateralslender seta; ventral surface covered with posteriorly directed cuticular flaps.First antenna (Figure 40C) five-segmented; armature (proximal to distal) as follows: first segment bearing one slender seta; second segment with six naked setae,three short setae with proximal denticulations / serrations plus one large curving, denticulated (prehensile) claw; third segment with nine slender setae plus one large distalspine; fourth segment with one slender seta; fifth (terminal) segment bearing 14 slen72der setae plus one aesthete. Second antenna (Figure 40D) five-segmented, prehensile. Basal segment short, second segment with short spiniform process and proximallydirected subtriangular cuticular flaps, third segment bearing rectangular cuticular flapsand two slender setae arising from base of well developed spiniform process. Fourthsegment elongate with many small triangular cuticular flaps along convex margin, fifthsegment an elongate unciform terminal claw bearing two slender setae and a very long,slender auxiliary spine. Mandible (not shown) of two parts, dentiferous margin witheight teeth. First maxilla (Figure 40E) biramous; sympod naked, endopod bearing twoapical setae (one smooth and one unilaterally denticulated); exopod longer surmountedby two small setae and one longer slender seta. Second maxilla (Figure 40F) brachiform, lacertus larger than brachium, with semicircular cuticular flaps, brachium withsemicircular cuticular flaps, a distal patch of prickles and two tufts of setae at base ofterminal claw (calamus). Claw bearing two pairs of serrated membranes. Maxilliped(Figure 40G) chelate, indistinctly segmented, proximal segment pedunculate; corpusmaxillipedis robust bearing small spiniform seta on distal margin, and rectangular cuticular flaps; myxal area expanded into large receptacle to accommodate claw of opposable segment. Shaft bearing two setae: one near midpoint on lateral convex marginand the other adjacent to a strip of membrane along concave distal margin. Claw(Figure 40G detail) unciform with reduced subquadrangular cuticular expansion producing a small lateral shield.First four pairs of legs biramous with three-segmented endopods, three-segmented exopods and two-segmented sympods. All basipods with lateral slender seta,first basipod bears additional distomedial slender seta. Ventral surfaces of all four legsbearing various shaped cuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-I 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure 41A) exopod three-segmented; exopodal setae with serratedmembrane along lateral margins, largest seta on terminal segment additionally bearsdenticulations along the distal portion of the medial edge, endopodal setae bilaterallydenticulated. Exopod two (Figure 41C) modified, first segment elongate with four rectangular cuticular flaps near proximal region and one distal papiiliform seta, secondsegment smaller, naked and bearing one papilliform seta, third segment armed with onesmall sub-apical seta plus two papilliform setae. Leg two endopod (Figure 41B) with73two naked setae on terminal segment. Legs three and four (Figure 41 D) setae stoutwith largest exopodal seta bearing denticles. Leg five (Figure 41 E) subcircular, distallybearing three small pinnate setae plus one similar seta arising dorsally from the base;lateral surface with subquadrangular and subtriangular cuticular flaps along lateral surface.Comments: Eudactylina papillosa has not been reported since its discovery anddescription by Kabata (1970) from gills of the stingray, Dasyatus kuhil.E. papillosa is easily distinguished from all other congeners by the papilliform(nipple-like) setae located on the modified exopod of leg two.Eudactylina peruensis Luque and Farfan, 1991.(Figures 42-43)Material examined. Six females (USNM 251 289) from the branchial lamellae ofthe shovelnose guitarfish Rhinobatos planiceps Garman, 1880 collected from inshorewaters near Chorrillos, Peru.DescriptionFemale (Figure 42A)Overall length in lateral view approximately 1.4 mm. Cephalothorax longer thanwide, lateral margin slightly notched accommodating lacertus of second maxillae.Anterolateral and dorsal surfaces of cephalothorax covered with cuticular flaps. Dorsaland ventrolateral surfaces of first, second, and third free thoracic somites covered withcuticular flaps; first and second free thoracic somites aliform. Fourth free thoracicsomite smaller than previous three, bearing leg five. Genital segment smaller than preceeding somite. Abdomen two-segmented, ventral surface bearing a pair of semicircular cuticular flaps on the posterior segment. Caudal ramus (Figure 42B) modified into adigitiform structure bearing two strongly sclerotized processes (fused modified setae?),one tiny proximal seta (sensifla?), one dorsomedial slender seta, one lateral slenderseta plus two ventrodistal short naked setae.First antenna (Figure 42C) five-segmented, armature (proximal to distal) as follows: first segment bearing one seta; second segment with five small slender setae,two large naked setae, one large bilaterally denticulated seta plus one large denticulated, curving (prehensile) claw; third segment with seven slender setae, two large stout74naked spines, plus one large uncinate denticulated spine; fourth segment with oneslender seta; terminal segment with one tiny seta, 11 long slender setae plus one aesthete. Second antenna (Figure 42D) five-segmented, prehensile. Basal segment short(not shown), second segment with long unciform process and triangular cuticular flaps,third segment bearing large hook-like process, three cuticular flaps and two slendersetae arising from near base of well produced spinous process. Fourth segment elongate and unarmed; fifth segment an unciform terminal claw bearing two slender setaeand one stout uncinate auxiliary spine. Mouth tube siphonostome and similar to that ofother species. Mandible (Figure 42E) of two parts, dentiferous margin with five teeth.First maxilla (Figure 42F) biramous; endopod bearing tiny triangular cuticular flaps andtwo apical setae, the longer with spinules or minute denticles; exopod longer surmounted by two small setae and one longer seta. Second maxilla (Figure 42G) brachiform,lacertus with large semicircular cuticular flaps, brachium with crescentic and subquadarangular cuticular flaps and one patch of prickles and one tuft of rope-like setaeat base of terminal claw (calamus). Claw bearing two rows of serrated membranesparallelling the claw plus two strips of membrane along the convex margin of other side,small basal process at base of lacertus. Maxilliped (Figure 42H) chelate, indistinctlysegmented, proximal segment pedunculate; corpus maxillipedis robust bearing slenderseta on distal margin and narrow cuticular flaps; myxal area expanded into large receptacle to accommodate claw of opposable segment. Shaft bearing two setae: one withpedunculate proximal region near midpoint on lateral convex margin and the other adjacent to a strip of membrane along concave distal margin. Claw complex, cuticularexpansions producing a fused complex of claw and cuticle.First four pairs of legs biramous, leg four with two-segmented endopod, three-segmented exopods and endopods on remaining rami, sympods two-segmented. Allbasipods with lateral slender seta; first basipod bears additional distomedial nakedseta. Ventral surfaces of all four legs bearing semicircular to subtriangular shapedcuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 - ILeg one (Figure 43A) exopodal setae unilaterally bearing serrated membranes,largest endopodal seta unilaterally bearing serrated flange, smaller naked. Exopod two75(Figure 43B) modified, first segment greatly elongated with tiny triangular cuticularflaps along the lateral margin and one distal naked seta, second segment smaller withnaked seta, third segment armed with one short naked seta, one longer curved nakedseta, plus one large curved unilaterally denticulated seta. Leg two endopod (Figure43B) with one small naked seta and one large bilaterally spinulated seta on terminalsegment. Scierite bar between leg two and leg three (Figure 43C) giving rise to a single, large medial stylet. Exopodal setae of legs three and four (Figures 43D and 43E)large and unilaterally denticulated, endopodal seta unilaterally bearing serrated membranous flange. Leg five (Figure 43F) longer than wide; lateral surface smooth, probably bearing three pinnate setae (only one intact in my specimens) plus one similar setaarising dorsally from the base.Male: UnknownComments: E. peruensis can be readily identified by the uniquely modified caudal ramus. The similarities of this structure with the caudal ramus of the new speciesEudactylina dactylocerca, described herein, plus the two-segmented endopod of legfour, suggest a close phylogenetic relationship. Interestingly, these two species andEudactylina rhinobati Essafi and Raibaut, 1979 share the posteriorly extended terga offree thoracic somites one and two, overlapping free thoracic somites two and three,respectively. All three infect Rhinobatos, from their respective waters.Eudactylina pollex Cressey, 1967(Figures 44-45)Material examined. Several females (USNM 271635) from the branchial lamellae of the great hammerhead, Sphyrna mokarran (Rüppell, 1837) collected fromSarasota, Florida, and several females (USNM 262099) from the same host speciescollected from the Caribbean Sea during a shark tagging expedition.DescriptionFemale (Figure 44A)Overall length in lateral view approximately 3.5 mm. Cephalothorax longer thanwide, lateral margin slightly notched accommodating lacertus of second maxillae.76Dorsolateral surfaces of cephalothorax covered with tiny triangular cuticular flaps.Cuticle of all body somites covered with patches of tiny triangular cuticular flaps. Fourthfree thoracic somite smaller than previous three with cuticular flaps on ventral surfaceand bearing leg five. Genital segment smaller than preceeding somite,with cuticularflaps on ventral surface. Abdomen (Figure 44B) two-segmented, ventral surface covered with tiny triangular cuticular flaps. Caudal ramus (Figure 44B) longer than wide,bearing two very large bilaterally denticulate setae plus one or two (too small for certainty) very tiny setae tipped with a tiny setule, one lateral slender seta plus one dorsomedial slender seta; ventral surface covered with posteriorly directed tiny triangularcuticular flaps.First antenna (Figure 44C) five-segmented, armature (proximal to distal) as follows: first segment bearing one stout seta; second segment with nine stout setae; thirdsegment with ten stout setae, plus one very robust seta (only eight total in figure); fourthsegment with one short stout seta; fifth (terminal) segment bearing 13 slender setaeplus one aesthete. Second antenna (Figure 44D) five-segmented, prehensile. Basalsegment short, second segment without spiniform process, bearing triangular cuticularflaps, third segment bearing a patch of rectangular cuticular flaps and a patch of tiny triangular flaps along convex margin, two slender setae arising from distal end of concaveedge. Fourth segment elongate with many small triangular cuticular flaps along convexmargin, fifth segment forming a stout unciform terminal claw bearing two short nakedsetae and a slender auxiliary spine. Mandible (Figure 44E) of two parts, dentiferousmargin with five teeth. First maxilla (Figure 44F) biramous; sympod naked or with spinules, endopod bearing two apical setae (one smooth and one sparsely semipinnate ordenticulated); exopod longer with or without spinules surmounted by two small stoutsetae and one longer seta with or without tiny spinules. Second maxilla (Figure 44G)brachiform, lacertus larger than brachium, with triangular cuticular flaps, brachium alsowith triangular cuticular flaps, a distal patch of densely packed triangular flaps and fourlarge elongate triangular flaps (modified setal tuft?) at base of terminal claw (calamus).Claw bearing two rows of teeth. Maxilliped (Figure 44H) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearing small seta ondistal margin, and two patches of tiny triangular cuticular flaps; myxal area expandedinto large receptacle to accommodate claw of opposable segment. Shaft bearing twoshort stout setae: one near midpoint on lateral convex margin and the other adjacent toa strip of membrane along concave distal margin. Claw (Figure 44H detail) unciformwith amorphous cuticular expansion bearing some very fine spinules along outer edgeproducing lateral shield.First four pairs of legs biramous with two-segmented endopod one, modified77endopod four and indistinctly three-segmented endopods two and three, three-segmented exopods and two-segmented sympods. All basipods with lateral slender seta,first basipod bears additional distomedial denticulated seta. Ventral surfaces of all fourlegs bearing triangular shaped cuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 1-0 III Endopod 0-0 - IILeg two Exopod 1-0 1-0 III Endopod 0-0 0-0 IIILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 -Leg one (Figure 45A) exopodal setae powerful claws with largest seta on terminal segment additionally bilaterally denticulate, endopodal setae bilaterally denticulated.Exopod two (Figure 45B) not modified, all exopodal setae manifest as powerful clawswith largest seta on terminal segment bilaterally denticulated, leg two endopod (Figure45B) with two denticulated stout setae and one seta on terminal segment. Legs threeand four (Figure 45C) with powerful claw-like setae, largest exopodal seta bilaterallydenticulate, endopod indistinctly segmented of leg three and partially fused in leg four(Figure 45D) into a two-segmented, bilaterally denticulated claw. Leg five (Figure 45E)ovoid; lateral surface with a few triangular cuticular flaps along lateral surface, distallybearing three small slender setae plus one similar seta arising dorsally from the base.Comments: Eudactylina pollex was reported by Cressey (1967 and 1970) fromthe great hammerhead, Sphyrna mokarran (Ruppell, 1837), collected from Madagascarand the West coast of Florida (Sarasota), and from the scalloped hammerhead,Sphyrna lewini (Griffith and Smith, 1834) from off the west coast of Florida. Thisredescription extends the known geographic range of E. pollexto the Caribbean.E. pollex is easily distinguished from all other congeners by the fused uncinateclaw-like nature of the third and especially the fourth endopod, and the lateral expansion of the proximal segment of endopods two, three, and four. Although the unusualabsence of an uncinate claw on the second segment of the first antenna appears to beunique to this species, it is probable that the large stout spine on the proximal portionon the third segment represents this structure. It is also possible this apparent displacement is more apparent than real. The highly sclerotized condition of the firstantenna makes it very difficult to accurately follow segmental boundaries.78Eudactylina pristiophori sp. nov.(Figures 46-47)Material examined. Three females from the branchial lamellae of the longnosesawshark, Pristiophorus cirratus (Latham, 1794) captured from near Green’s Beach atthe Tamar River mouth, northern Tasmania. Specimen (USNM 205516) examined atthe Smithsonian’s Support Center, National Museum of Natural History, SmithsonianInstitution, Washington, D.C. Female holotype (USNM 266529) and 1 female paratype(USNM 266530) deposited at the United States National Museum of Natural History.Etymology: The specific name pristiophori refers to the generic name of the host.DescriptionFemale (Figure 46A)Overall length in lateral view approximately 1.8 mm. Cephalothorax longer thanwide, lateral margin slightly concave. Surface of cephalothorax, first, second, thirdand, fourth free thoracic somites covered with cuticular flaps. Fourth tree thoracicsomite, genital segment and, two-segmented abdomen all bearing cuticular flaps onventral surface. Caudal ramus (Figure 46B) bearing terminally two very squat curvedsetae, plus two elongate slender setae (one dorsomedial, one lateral).First antenna (Figure 46C) apparently four-segmented, armature (proximal todistal) as follows: first segment bearing one slender seta; second segment with fourdenticulated setae (3 small, one large), four naked setae (two small, one large, onepapilliform), and one large denticulated, curving (prehensile) claw; third segment witheight naked setae, one stout naked spine, plus one large denticulated spine; fourthsegment with 14 slender setae plus one aesthete. Second antenna (Figure 46D) five-segmented, prehensile. Basal segment short, second segment devoid of cuticular flapswith short spinous process, third segment bearing proximally directed irregular rectangular cuticular flaps and two slender setae arising from near base of curving spinousprocess. Fourth segment elongate and unarmed; fifth segment an unciform terminalclaw bearing two slender setae and one curving auxiliary spine. Mouth tube siphonostome and similar to that of other species. Mandible (Figure 46E) of two parts, dentiferous margin with eight teeth. First maxilla (Figure 46F) biramous; endopod more robustbearing two unilaterally denticulated apical setae; exopod longer and surmounted bytwo small setae and one longer, unilaterally denticulated seta. Second maxilla (Figure46G) brachiform, lacertus larger than brachium bearing semicircular cuticular flaps andsmall basal process, brachium with semicircular and rectangular cuticular flaps, a distal79patch of triangular prickles and two tufts of setae (one coarse or rope-like (possiblyfused setae) and one fine or hair-like at base of terminal claw (calamus)). Claw bearing four pairs of serrated membranes. Maxilliped (Figure 46H) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearing small setaon distal margin and small rectangular cuticular flaps; myxal area expanded into areceptacle to accommodate claw of opposable segment. Shaft bearing two setae: onenear midpoint and the other along concave distal margin near membranous strip (seedetail). Claw (Figure 46H detail) unciform bearing cuticular flange and a quadrate lateral shield.First four pairs of legs biramous and trimerite, sympods two-segmented. Allbasipods with lateral slender seta; first basipod bears additional distomedial slenderseta. Ventral surfaces of legs two, three, and four bearing cuticular flaps. Armature oframi as follows:Leg one Exopod 1-0 1-0 IV Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure 47A) lateral margins of proximal segments with single row offine triangular cuticular flaps; lateral exopodal setae unilaterally bearing serrated membranous membrane, largest apical exopodal seta bilaterally denticulated, smallest slender and naked, endopodal setae bilaterally denticulated. Leg two exopod (Figure 47C)modified, first segment greatly enlarged with thick seta, second segment with stoutseta, terminal segment with one small naked setae, one small recurving seta plus onetruncate seta, endopod (Figure 47B) tipped with two bilaterally denticulated setae.Legs three and four (Figure 47D) similar; all exopodal setae denticulated, endopodstipped by single finely denticulated seta. Leg five (Figure 47E) slightly longer than wide,distally bearing three spiniform setae plus one seta arising dorsally from the base; lateral surface with small subquadrangular cuticular flaps.Male: UnknownComments: Eudactylina pristiophori is the first record of a parasitic copepodinhabiting the Pristiophoriformes (sawsharks).This species is readily identified by the very short, stout, and apically curving terminal setae on the caudal rami. Additionally, it is the only species in the genus with a80stout papilliform seta on segment two of the first antenna. Also, no other species bearsthe unique combination of two slender setae with lateral serrated membranes, an elongate bilaterally denticulated (not semipinnate) seta, and a medial small slender seta onthe terminal segment of the first exopod.Eudactylina pusilla Cressey, 1967(Figures 48-49)Material examined. Several females (USNM 153628) from the branchial lamelIae of the tiger shark, Galeocerdo cuvier (Peron and LeSueur, 1822) collected fromSarasota, Florida.DescriptionFemale (Figure 48A)Overall length in lateral view approximately 4.4 mm. Cephalothorax longer thanwide, lateral margin deeply notched accommodating lacertus of second maxillae.Dorsolateral surfaces of cephalothorax covered with cuticular flaps. Cuticle of free thoracic somites one-four covered with cuticular flaps. Fourth free thoracic somite smallerthan previous three with cuticular flaps on ventral surface and bearing leg five. Genitalsegment smaller than preceeding somite,with cuticular flaps on ventral surface.Abdomen two-segmented, ventral surface bearing cuticular flaps. Caudal ramus(Figure 48B) longer than wide, bearing three terminal large blunt (nearly amorphous)setae (the two lateralmost with a row of fine denticles), one lateral slender seta plus onedorsomedial slender seta; ventral surface with a few posteriorly directed tiny triangularcuticular flaps.First antenna (Figure 48C) five-segmented, armature (proximal to distal) as follows: first segment bearing one stout seta; second segment with six thick naked setaetwo slender naked setae, plus one finely denticulated curving (prehensile) claw; thirdsegment with nine thick naked setae and one large spine; fourth segment with oneslender seta; fifth (terminal) segment bearing 13 slender setae plus one aesthete.Second antenna (Figure 48D) five-segmented, prehensile. Basal segment short, second segment without spinous process, bearing subrectangular cuticular flaps, third segment bearing a patch of subrectangular cuticular flaps and two slender setäe arisingfrom base of small spinous extension. Fourth segment elongate with many small triangular cuticular flaps along convex margin, fifth segment forming a stout unciform termi81nat claw bearing two slender setae and a single thick auxiliary spine. Mandible (Figure48E) of two parts, dentiferous margin with five teeth. First maxilla (Figure 48F) biramous; endopod with triangular cuticular flaps bearing two denticulated setae; exopodlonger with subtriangular flaps surmounted by two small denticulated setae and onelonger denticulated seta. Second maxilla (Figure 48G) brachiform, lacertus larger thanbrachium with semicircular cuticular flaps and basal process, brachium also with semicircular cuticular flaps, and distal patch of coarse setae at base of terminal claw (calamus). Claw bearing two rows of teeth distally and two strips of serrated membranesproximally. Maxilliped (Figure 49A) chelate, indistinctly segmented, proximal segmentpedunculate; corpus maxillipedis robust bearing small seta on distal margin, and patches of tiny triangular cuticular flaps; myxal area expanded into large receptacle toaccommodate claw of opposable segment. Shaft bearing two stout setae: one nearmidpoint on lateral convex margin and the other adjacent to a strip of membrane alongconcave distal margin. Claw (Figure 49A detail) unciform with small cuticular expansion producing lateral shield.First four pairs of legs biramous and trimerite. All basipods with lateral pinnate tosemipinnate setae, first basipod bears additional distomedial denticulated seta. Ventralsurfaces of all four legs bearing triangular shaped cuticular flaps. Armature of rami asfollows:Leg one Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg two Exopod 1-0 1-0 Ill Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one exopodal setae (Figure 49B) denticulated, endopodal setae (Figure49C) bilaterally denticulated. Exopod two (Figure 49D) modified, all exopodal setaenaked except largest seta on terminal segment unilaterally denticulated, terminal segment atypically hemispherical in shape with setae displaced to medial margin, leg twoendopod (Figure 49E) with two small naked setae on terminal segment. Setae of legsthree and four (Figure 49F) claw-like with largest exopodal seta unilaterally denticulated, endopod tipped with a single bilaterally denticulated seta. Leg five (Figure 49G)wider than long, distally bearing three sparsely pinnate setae plus one seta arising dorsally from the base; lateral surface covered with subtriangular cuticular flaps along lateral surface.82Comments: Eudactylina pusilla was reported by Cressey (1967, 1970) from gillsof the tiger shark, Galeocerdo cuvier (Peron and LeSueur, 1822), collected fromMadagascar and the West coast of Florida near Sarasota.E. pusilla is easily distinguished from all other congeners by the large blunt(nearly amorphous) denticulated setae on the caudal rami and by the unusual shape ofthe terminal segment on the second (modified) exopod and the lateral displacement ofthe three setae which are usually found terminally.Eudactylina similis T.Scott, 1902(Figures 50-51)Syn: Eudactylina rachelaeGreen, 1958, (see Kabata, 1979)Material examined. Numerous females from the branchial lamellae of thePacificelectric ray, Torpedo ca/ifornica (Ayres), and the big skate Raja binoculata Girard, captured near Palos Verdes, southern California.DescriptionFemale (Figure 50A)Overall length in lateral view approximately 4.5 mm. Cephalothorax longer thanwide, lateral margin slightly concave. Dorsolateral surface of cephalothorax, first, second, third and, fourth free thoracic somites covered with cuticular flaps. Fourth freethoracic somite, genital segment and, two-segmented abdomen all bearing cuticularflaps on ventral surface. Caudal ramus (Figure 50B) with two terminal stout setae, onelateral slender seta, and one dorsomedial slender seta.First antenna (Figure 500) apparently four-segmented, but could be interpretedas seven-segmented; armature (proximal to distal) as follows: first segment bearing oneshort seta; second segment with three denticulated slender setae (two small, onelarge), five naked setae and one large denticulated, curving (prehensile) claw; thirdsegment with a proximal group of five slender setae (one denticulated) and a distalgroup of three setae (two slender, one stout) plus one large denticulated spine; fourthsegment elongate with one proximal slender seta, and either 13 or 14 setae with eitherone or two aesthetes respectively. Second antenna (Figure 50D) five-segmented, prehensile. Basal segment short, second segment devoid of cuticular flaps with smallspinous process, third segment bearing proximally directed subrectangular cuticular83flaps, distally directed subtriangular flaps along convex margin, and two slender setaearising from near base of large spinous process. Fourth segment elongate with cuticular flaps along convex margin; fifth segment an unciform terminal claw bearing two slender setae and one curving auxiliary spine. Mouth tube siphonostome and similar to thatof other species. Mandible (Figure 50E) of two parts, dentiferous margin with seventeeth. First maxilla (Figure 50F) biramous; endopod with triangular cuticular flaps bearing two denticulated apical setae; exopod longer and surmounted by two small nakedsetae and one longer, bilaterally denticulated thick seta. Second maxilla (Figure 50G)brachiform, lacertus slightly larger than brachium bearing semicircular cuticular flaps,brachium with semicircular cuticular flaps, a distal patch of triangular prickles and twotufts of setae and possibly a small spine at base of claw (calamus). Claw bearing multiple strips of serrated membranes. Maxilliped (Figure 50H) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearing minute setaon distal margin and small rectangular cuticular flaps; myxal area expanded into areceptacle to accommodate claw of opposable segment. Shaft bearing two setae: onenear midpoint and the other along concave distal margin near membranous strip (seedetail). Claw (Figure 50H detail) unciform bearing cuticular flange and a subquadratelateral shield.First four pairs of legs biramous and trimerite, sympods two-segmented. AHbasipods with lateral slender seta; first basipod bears additional distomedial slenderseta. Ventral surfaces of legs two, three, and four bearing cuticular flaps. Armature oframi as follows:Leg one Exopod 1-0 1-0 IV Endopod 0-0 0-0 IILeg two (modified) Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 Ill Endopod 0-0 0-0 ILeg one (Figure 51A) lateral margins of proximal segments with singie row offine triangular cuticular flaps; lateral exopodal setae unilaterally bearing serrated membranous flange, largest apical exopodal seta bilaterally denticulated, smallest with distalsetules, endopodal setae slender and bilaterally denticulated. Leg two exopod (Figure51C) modified, first segment greatly enlarged with stout seta, second segment withsquat papilliform seta, terminal segment with one small naked seta, one small recurvingseta plus one truncate seta, endopod (Figure 51 B) tipped with two slender bilaterallyspinulated setae. Legs three and four (Figure 51D) similar; all exopodal setae denticulated, endopod tipped by single finely denticulated slender seta. Leg five (Figure 51E)84longer than wide, distally bearing three slender setae plus one seta arising dorsallyfrom the base; lateral surface with small cuticular flaps.Male: Not obtainedComments: Eudactylina s/mills was first described by Scott (1902) in Britishwaters from gills of the thorny skate, Raja radiata Donovan, and the skate Raja fulloniCa. Green (1958) discovered it on the Atlantic torpedo, Torpedo nobiliana Bonaparte,and erroneously established a new species E. rachelae, for that record. Also, DelamareDeboutteville and Nunes-Ruivo (1958) discovered E. s/mills on Raja asterias in theMeditteranean. Boxshall (1974) found it on Raja montagui and Raja naevus in theNorth Sea, and Kabata (1979) found this copepod on the longnose skate, Raja rh/naJordan and Gilbert, and on the starry skate, Raja stellulata Jordan and Gilbert, in theeastern North Pacific near Vancouver Island. This report adds the big skate, Rajabinoculata Girard and the Pacific electric ray, Torpedo californica Ayres both from nearPalos Verdes in southern California to the list. The finding of E. s/mills on Torpedo cal/torn/ca supports the synonymy of E. rachelae and E. s/mills. This copepod is apparently a common parasite of both Raja and Torpedo worldwide.This species can be readily identified by the many small denticles scattered overthe convex surface of the large prehensile claw on the second segment of the firstantenna, and the apparently unique possession (in the genus) of two aesthetes on thedistal segment (s) of the first antenna.Eudactylina squamosa Bere, 1936(Figures 52-53)Mater/al examined. Several females from the branchial lamellae of the cow noseray Rhinoptera bonasus (Mitchill, 1815) collected from the West Coast of Florida (Gulfof Mexico), donated to me by Dr. Roger Cressey (personal collection), SmithsonianInstitution; and two females from the gills of the cow nose ray, Rhinoptera ste/ndacheriEvermann and Jenkins, 1891 collected from Punta Arena de Ia Ventana, in the southern Sea of Cortez (Gulf of California).DescriptionFemale (Figures 52A, B)Overall length in lateral view approximately 1 .2 mm. Cepalothorax longer than85wide, lateral margin notched accomodating lacertus of second maxillae. Entire surfaceof cephalothorax covered with cuticular flaps. Cuticular flaps present on surfaces offirst, second, third and fourth free thoracic somites. Fourth free thoracic somite bearingleg five. Fourth free thoracic somite, genital segment, and abdomen bearing posteriorlydirected cuticular flaps on ventral surface. Genital segment smaller than preceedingsomite. Abdomen two-segmented. Caudal ramus (Figure 52C) longer than wide, bearing two terminal stout setae, one very small medial seta, one dorsomedial slender seta,one lateral slender seta, and one proximal seta near the lateral edge (possibly homologous to the typical setule seen in this area in other species); ventral surface armed withposteriorly directed su btriangu lar cuticular flaps.First antenna (Figure 52D) apparently four-segmented, armature (proximal todistal) as follows: first segment bearing one seta; second segment with five smallnaked setae, two large setae plus one curving, denticulated (prehensile) claw; thirdsegment bearing nine naked setae, terminal segment armed with 15 smooth slendersetae plus one aesthete. Second antenna (Figure 52E) five-segmented, prehensile.Basal segment short, second segment armed with blunt spinous process, third segmentbearing three cuticular flaps and two setae (one of them nearly the size of spinousprocess) arising from base of well produced spinous process. Fourth segment elongateand unarmed; fifth segment an unciform terminal claw bearing two slender setae andone stout auxiliary spine. Mouth tube siphonostome and similar to that of otherspecies. Mandible (Figure 52F) of two parts, dentiferous margin with seven teeth. Firstmaxilla (Figure 52G) biramous; endopod larger bearing two elongate setae, longer setaunilaterally denticulated, exopod shorter surmounted by two small naked setae and onelonger slender seta. Second maxilla (Figure 52H) brachiform, lacertus larger thanbrachium with basal process and bearing cuticular flaps, brachium with irregular triangular cuticular flaps, a distal patch of coarse setae and apparently a small spine atbase of terminal claw (calamus). Claw bearing three rows of serrated membranes distally, plus one longer serrated strip proximally. Maxilliped (Figure 521) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearingsmall stout spine on distal margin, and devoid of cuticular flaps; myxal area expandedinto large receptacle to accommodate claw of opposable segment. Shaft bearing twosetae: one near midpoint on lateral convex margin and the other near concave distalmargin. Claw unciform with small lateral shield.First four pairs of legs biramous and trimerite, two-segmented sympods. Allbasipods with lateral slender seta; first basipod bears additional distomedial seta tippedwith two setules. Ventral surfaces of all four legs bearing subtriangular cuticular flaps.Armature of rami as follows:86Leg one Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg two Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure 53A) exopodal setae thick bearing lateral denticulations, endopod with one slender seta and one larger seta bilaterally denticulated. Leg two (Figure53B) exopod not modified and bearing subtriangular cuticular flaps, first segmentlargest with one distal stout seta, second segment smaller bearing single stout seta,third segment armed with three small stout setae. Leg two endopod (Figure 53B) withtwo bilaterally denticulated setae (one small, one large). Exopods of legs three andfour (Figure 53C) with claw-like setae, largest seta on terminal segment with denticles,terminal segment of endopods three and four (Figure 53C) bearing single thick bilaterally denticulated seta. Leg five (Figure 53D) longer than wide, distally bearing three slender setae plus one similar seta arising dorsally from the base; lateral surface sparselycovered with triangular cuticular flaps.Male: UnknownComments: E. squamosa has not been reported since its discovery by Bere(1936) on Rhinoptera bonasus from Lemon Bay, Florida. This report from Rhinopterasteindacheri extends the host spectrum and geographic range of the parasite. Thespecimen dissected and studied from the Gulf of California from A. steindacheridifferedfrom its counterpart from the Gulf of Mexico by possessing cuticular flaps on the maxilliped, cuticular flaps on the fourth segment of the second antenna, cuticular flaps on thepenultimate segment of the first antennae, and terminal elements on the caudal ramiappearing a bit more amorphous and claw-like. Until more specimens are looked at Ifeel it is best to treat these differences as intraspecific. In either case, this (or these)species seem to be specific to the rhinopte rids.The squat habitus, the relatively short expansion of the corpus maxillipedis coupled with the transverse palm of the corpus (resulting in a reduced aperture) readily distinguish this species. Additionally, the thick setae approximating the dimensions of thespiniform process of the third segment of the second antenna are unique to thespecies. The relative lengths of the terminal setae on the third segment of the unmodified second exopod decrease from the lateral to the medial margins, in sharp contrastto what occurs in the other species.87Eudactylina tuberifera Castro and Baeza, 1987(Figures 54-55)Material examined. Several females (USNM 213114) from the branchial lamellae of the southern angelote, Squat/na armata (Philippi, 1887), collected from the eastern South Pacific near Antofagasta, Chile.DescriptionFemale (Figure 54A)Overall length in lateral view approximately 1.8 mm. Cephalothorax longer thanwide, lateral margin notched accommodating lacertus of second maxillae. Entire surface of cephalothorax covered with cuticular flaps. Cuticular flaps present on surfacesof first, second, third and fourth free thoracic somites. Fourth free thoracic somite bearing leg five. Fourth free thoracic somite, genital segment, and abdomen bearing posteriorly directed cuticular flaps on ventral surface. Genital segment smaller than preceeding somite. Abdomen two-segmented. Caudal ramus (Figure 54B) longer than wide,bearing two terminal apically curved stout setae, one dorsomedial slender seta, andone lateral slender seta; ventral surface armed with posteriorly directed cuticular flaps.First antenna (Figure 54C) indistinctly four-segmented, armature (proximal todistal) as follows: first segment bearing one naked seta; second segment with fivesmall naked setae, two large naked setae (one elongate, one stout), one elongatebilaterally denticulated seta plus one curving, denticulated (prehensile) claw; third segment bearing six slender setae, one short stout seta, one large naked spine, and onelarge denticulated spine, terminal segment armed with 14 naked slender setae, onelong unilaterally denticulated seta plus one aesthete. Second antenna (Figure 54D)five-segmented, prehensile. Basal segment short second segment armed with spiniform process, third segment bearing proximally directed cuticular flaps and two slendersetae arising from base of well produced spinous process. Fourth segment elongateand unarmed; fifth segment an unciform terminal claw bearing two slender setae andone well developed auxiliary spine. Mouth tube siphonostome and similar to that ofother species. Mandible (Figure 54E) of two parts, dentiferous margin with eight teeth.First maxilla (Figure 54E) biramous; endopod with triangular cuticular flaps and bearingtwo slender setae, longer seta denticulated, exopod longer surmounted by two smallsetae and one longer bilaterally denticulated seta. Second maxilla (Figure 54F) brachiform, lacertus larger than brachium and bearing cuticular flaps, brachium with irregularcuticular flaps, and two tufts of setae (one coarse or rope-like (possibly fused setae)and one fine or setule-like at base of terminal claw (calamus)). Claw bearing four rows88of serrated membranes distally, plus one longer serrated strip proximally, two strips ofserrated membranes flanking concave surface on opposite side. Maxilliped (Figure55A) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearing small stout spine on distal margin, and large patch of cuticularflaps; myxal area bearing large transverse cuticular flap along anteroventral margin andexpanded into large receptacle to accommodate claw of opposable segment. Shaftbearing two setae: one near midpoint on lateral convex margin and the other adjacentto membranous strip along concave distal margin. Claw (Figure 55A, detail) unciformwith subrectangular lateral shield.First four pairs of legs biramous and trimerite, two-segmented sympods. Allbasipods with lateral slender seta; first basipod bears additional distomedial slenderseta. Ventral surfaces of all four legs bearing variously shaped cuticular flaps.Armature of rami as follows:Leg one Exopod 1-0 1-0 Ill Endopod 0-0 0-0 IILeg two Exopod 1-0 1-0 Ill Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 Ill Endopod 0-0 0-0 1Leg four Exopod 1-0 1-0 1W Endopod 0-0 0-0 ILeg one (Figure 55B) exopodal setae bearing lateral serrated cuticular expansions, endopodal setae and bilaterally denticulated. Leg two exopod (Figure 55C)modified and bearing subtriangular cuticular flaps along lateral margin, first segmentgreatly enlarged with one distal, toothed stout seta, second segment smaller. bearingsingle stout, naked seta, third segment armed with one small slender seta, one truncateseta, and one recurving seta. Leg two endopod (Figure 55D) with two bilaterally denticulated slender setae. Exopods of legs three and four (Figure 55E) with stout toothedsetae, terminal segment of endopods three and four (Figure 55F) bearing single thickbilaterally denticulated seta. Leg five (Figure 55G) longer than wide, distally bearingthree slender naked setae plus one pinnate seta arising dorsally from the base; lateralsurface with cuticular flaps.Male: Not obtainedComments: E. tuberifera, the parasite of the southern angelote Squat/na armata, is very similar to E. acuta, a parasite of the Mediterranean angeishark, Squat/nasquat/na and to the new species E. aphiloxenos, parasitizing the Pacific angelshark,Squat/na cailforn/ca off the southern California coast. Castro and Baeza (1987) claim89the swollen third segment of the second antenna of the female is a diagnostic characterof this species. However, this is not so; the second antenna is quite typical of theentire genus and the specimens examined did not display this accentuated trait.This species, and its two aforemetioned allies, E. acuta and E. aphiloxenous,share the large tines found on the setae of exopods three and four, and the difficult todistinguish four- or five-segmented first antenna. The serrated membranes on the lateral edge of the setae on exopod one, possessing three setae on the terminal segmentof exopod one (not four), and the row of cuticular flaps along the lateral edge of themodified exopod of leg two, separate this species from the two remaining squatinid parasitizing copepods.Eudactylina turgipes Bere, 1936(Figures 56-57)Material examined. Several females (USNM 155196) from the branchial lamellae of the butterfly ray Gymnura sp. collected from Lemon Bay, Florida (Gulf ofMexico), additional specimens from same host species and locality donated to me byDr. Roger Cressey (personal collection), Smithsonian Institution.DescriptionFemale (Figure 56A)Overall length in lateral view approximately 1.7 mm. Cephalothorax longer thanwide, lateral margin notched accomodating lacertus of second maxillae. Entire surfaceof cephalothorax covered with cuticular flaps. Cuticular flaps present on surfaces offirst, second, third and fourth free thoracic somites. Fourth free thoracic somite bearingleg five. Fourth free thoracic somite, genital segment, and abdomen bearing posteriorlydirected cuticular flaps on ventral surface. Single median intersomitic stylet presentbetween leg three and four (Figure 57A). Genital segment smaller than preceedingsomite. Abdomen two-segmented. Caudal ramus (Figure 56B) longer than wide, bearing four terminal setae (two small unilaterally denticulated setae, one small naked seta,and one elongate bilaterally denticulated seta), one dorsomedial slender seta, and onelateral slender seta; ventral surface armed with posteriorly directed subtriangular cuticular flaps.First antenna (Figure 56C) indistinctly four-segmented, armature (proximal todistal) as follows: first segment bearing one small slender seta; second segment with90four small naked setae, one small unilaterally denticulated seta, two elongate nakedsetae, one large stout seta plus one curving, denticulated (prehensile) claw; third segment bearing eight slender naked setae, one stout naked spine, and one large denticulated spine, terminal segment armed with 15 slender setae plus one aesthete. Secondantenna (Figure 56D) five-segmented, prehensile. Basal segment short, second segment armed with spinous process, third segment bearing two rows of proximally directed subrectangular cuticular flaps and two slender setae arising from base of long spinous process. Fourth segment elongate and unarmed; fifth segment an elongate, unciform terminal claw bearing two slender setae and one elongate auxiliary spine. Mouthtube siphonostome and similar to that of other species. Mandible (Figure 56E) of twoparts, dentiferous margin with eight teeth. First maxilla (Figure 56F) biramous; endopod bearing one unilaterally denticulated seta and one longer bilaterally denticulatedseta, exopod longer surmounted by two small naked setae and one longer bilaterallyspinulated (sparsely pinnate) slender seta. Second maxilla (Figure 56G) brachiform,lacertus larger than brachium and bearing a proximal patch of triangular cuticular flapsadjacent to basal process and wavy cuticular flaps on other side, brachium with wavy(sinusoidal) cuticular flaps, a distal patch of triangular flaps (prickles) and one tuft ofcoarse setae at base of terminal claw (calamus). Claw bearing one pair of serratedmembranes distally and another pair proximally, two strips of serrated membranesflanking concave surface on opposite side. Maxilliped (Figure 56H) chelate, indistinctlysegmented, proximal segment pedunculate; corpus maxillipedis robust bearing smallstout spine on distal margin, and large patch of sinusoidal cuticular flaps; myxal areaexpanded into large receptacle to accommodate claw of opposable segment. Shaftbearing two setae: one large stout seta near midpoint on lateral convex margin and theother adjacent to elongate membranous strip along concave distal margin. Claw(Figure 56H, detail) complex with ovoid lateral shield.First leg biramous and bimerite, legs two three and four biramous and trimerite,two-segmented sympods. All basipods with lateral pinnate seta; first basipod bearsadditional distomedial slender seta. Ventral surfaces of all four legs bearing semicircular, triangular, and rectangular shaped cuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 - 1111 Endopod 0-0 - IILeg two Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure 57A) exopodal setae distally bearing serrated cuticular expan91sions, longest seta on terminal segment bilaterally bearing tiny spinules, endopod withunusual array of semicircular cuticular flaps wrapping around lateral margin of elongated terminal segment, setae bilaterally spinulated. Leg two exopod (Figure 57B) modified, bearing minute triangular cuticular flaps along lateral margin, first segment greatlyenlarged, second and third segments compressed with a few tiny triangular flaps, allsetae robust and papilliform. Leg two endopod (Figure 57C) with relatively large proximal segment and rectangular cuticular flaps, terminal segment apically bears two pinnate slender setae. Exopods of legs three and four (Figure 57D) with apically toothedsetae, largest seta on terminal segment pinnate, terminal segment of endopods threeand four bearing single pinnate seta. Leg five (Figure 57E) longer than wide, distallybearing three pinnate setae plus one similar seta arising dorsally from the base; lateralsurface with triangular cuticular flaps. lntersomitic stylet (Figure 57F) plunging downbetween pediger three and pediger four.Male: UnknownComments: E. turgipes was first recorded by Bere (1936) from gills of the butterfly ray Pteroplatea maclura (= Gymnura maclura); it was subsequently found byPearse (1952a) from the smooth butterfly ray, Aetoplatea micrura (= Gymnura micrura,(Bloch and Schneider)), and most recently it turned up again (Raibaut et al., 1971) inTunisian waters (Medittereanean Sea) from the gills of the spiny butterfly ray, Gymnuraaltevela (Linnaeus). This additional record from Gymnura sp. from Lemon Bay, Floridastrongly suggests E. turgipes is specific to butterfy rays of the genus Gymnura.This species is easily distinguished by the peculiarly swollen modified exopod ofleg two, the papilliform setae of exopod two, the unique combination of setal characteristics on the caudal ramus, the bimerite condition of the exopod and endopod of legone, the apparently bifid ventral stylet, and the four semicircular flaps wrapping aroundthe lateral margin of the elongated terminal segment of the endopod of leg one.Eudactylina urolophi sp. nov.(Figures 58-59)Material examined. Several females from the branchial lamellae of the roundstingray Urolophus halleri Cooper collected from Los Angeles Harbor and Sel Beach,California. Female holotype (USNM 266566) and 1 female paratype (USNM 266567)92deposited at the United States National Museum of Natural History.Etymology: The specific name urolophi refers to the generic name of the host.DescriptionFemale (Figure 58A)Overall length in lateral view approximately 2.3 mm. Cephalothorax longer thanwide, lateral margin notched accommodating lacertus of second maxillae. Dorsolateralsurface of cephalothorax covered with cuticular flaps. Cuticular flaps present on surfaces of first, second, third and fourth free thoracic somites. Fourth free thoracic somitebearing leg five. Fourth free thoracic somite, genital segment, and abdomen bearingposteriorly directed cuticular flaps on ventral surface. Genital segment smaller than preceeding somite. Abdomen two-segmented. Caudal ramus (Figure 58B) longer thanwide, bearing two stout setae, one dorsomedial slender seta (not illustrated), and onelateral slender seta; ventral surface armed with posteriorly directed triangular cuticularflaps.First antenna (Figure 58C) apparently four-segmented, armature (proximal todistal) as follows: first segment bearing one small slender seta; second segment withonly four slender setae observed (certainly more exist but were missed) plus one curving, denticulated (prehensile) claw; third segment bearing three small setae and oneelongate slender seta (again, more are certain to exist but were missed) plus one stoutseta and one large denticulated spine, terminal segment with only 10 slender setaeobserved plus one aesthete. Second antenna (Figure 58D) five-segmented, prehensile. Basal segment short, second segment armed with spinous process and singlesubrectangular cuticular flap, third segment bearing proximally directed subrectangularcuticular flaps with two slender setae arising from base of spinous process. Fourth segment elongate and unarmed; fifth segment an elongate, unciform terminal claw bearingtwo slender setae and one elongate auxiliary spine. Mouth tube siphonostome andsimilar to that of other species. Mandible (Figure 58E) of two parts, dentiferous marginwith six teeth. First maxilla (Figure 58F) biramous; endopod bearing two naked setae,exopod longer surmounted by two small naked setae and one longer naked seta.Second maxilla (Figure 58G) brachiform, lacertus larger than brachium, brachium withrectangular cuticular flaps, a distal patch of triangular flaps (prickles) and two tufts ofsetae (one coarse and one fine) at base of terminal claw (calamus). Claw bearing serrated membrane distally and another strip along concave margin. Maxilliped (Figure58H) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearing small stout seta on distal margin, and five large rectangular cuticu93lar flaps; myxaf area expanded into large receptacle to accommodate claw of opposable segment. Shaft bearing two setae: one large naked seta near midpoint on lateralconvex margin and the other adjacent to elongate membranous strip along concavedistal margin. Claw with subquadrangular lateral shield.First leg biramous and bimerite, legs two three and four biramous and trimerite,two-segmented sympods. All basipods with lateral slender seta; first basipod bearsadditional distomedial seta (not shown). Ventral surfaces of all four legs bearing triangular and rectangular shaped cuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 - 1111 Endopod 0-0 - IILeg two Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 Ill Endopod 0-0 0-0 ILeg one (Figure 59A) exopodal setae laterally bearing serrated cuticular expansions (membranes), longest seta on terminal segment slender and naked, endopodwith elongated terminal segment, setae slender and naked. Leg two exopod (Figure59B) modified, bearing minute cuticular flaps along lateral margin and small triangularflaps along medial edge, first segment greatly enlarged, second and third segmentssmaller, terminal segment with truncate seta, one short slender seta, and one recurvingseta. Leg two endopod (Figure 59B) with relatively large lateral protuberance on proximal segment, terminal segment apically bears two naked slender setae. Exopods oflegs three and four (Figure 59C) with unilaterally denticulated setae, seta on proximalsegment of endopods with serrated membrane. Leg five (Figure 59D) longer than wide,distally bearing three slender setae plus one seta arising dorsally from the base; lateralsurface with rectangular and triangular cuticular flaps.Male: UnknownComments: E. urolophi is the first eudactylinid to be reported from the genusUrolophus. Only three species possess both a two-segmented endopod and two-segmented exopod on the first leg. These species are E. epaktoIampter E. corrugata, andE. turgipes. Of these three species, both E. epaktolampter and E. turgipes possesscaudal rami bearing six setae, E. urolophi bears only four setae on the caudal ramus.This simple combination sets E. urolophi apart from the remaining species in thegenus.94Eudactylina vaquetillae sp. nov(Figures 60-61)Material examined. Several females branchial lamellae of the vaquetilla, Mobulatarapacana (Philippi, 1892) collected from Punta Arena de Ia Ventana in the .southernSea of Cortez (Gulf of California). Female holotype (USNM 266531) and 5 femaleparatypes (USNM 266532) deposited at the United States National Museum of NaturalHistory.Etymology: The specific name vaquetillae refers to the local vernacular name ascribedto this very large mobulid.DescriptionFemale (Figure 60A)Overall length in lateral view approximately 3.3 mm. Cephalothorax longer thanwide, lateral margin notched accomodating lacertus of second maxillae. Lateral anddorsal surfaces of cephalothorax covered with cuticular flaps. Cuticle of first, second,and third free thoracic somites covered with cuticular flaps. Fourth free thoracic somitesmaller than previous three with cuticular flaps on ventral surface and bearing leg five.Genital segment smaller than preceeding somite,with cuticular flaps on dorsal.and ventral surfaces. Abdomen two-segmented, ventral surface bearing cuticular flaps. Caudalramus (Figure 60B) ellipsoid, bearing four terminal short stout setae (only three illustrated), one dorsomedial slender seta and one ventrolateral slender seta; ventral surfacecovered with variously directed semicircular cuticular flaps.First antenna (Figure 60C) indistinctly five-segmented, armature (proximal to distal) as follows: first segment with cuticular flaps along lateral margin bearing one tinystout seta; second segment with eight naked setae plus one large, curving (prehensile)claw; third segment with a proximal cluster of six naked setae (only four illustrated)plus a distal cluster of three naked setae and a stout spine; fourth segment bearingone slender seta, terminal segment with 14 slender setae plus one aesthete. Secondantenna (Figure 61A) five-segmented, prehensile. Basal segment short, second segment elongate bearing many small semicircular cuticular flaps, third segment bearingproximally directed rectangular cuticular flaps, two slender setae arising from near baseof very reduced spinous (possibly absent) process. Fourth segment elongate withmany semicircular cuticular flaps, fifth segment an elongate unciform terminal clawbearing two slender setae and one similar in size, slender auxiliary spine. Mouth tube95siphonostome and similar to that of other species. Mandible (Figure 60D) of one part,dentiferous margin with six teeth. First maxilla (Figure 60D) biramous; sympod withsmall patches of spinules, endopod bearing two stout setae, one unilaterally denticulated; exopod longer surmounted by two small naked setae and one longer bilaterallydenticulated seta. Second maxilla (Figure 60E) brachiform, lacertus larger than brachium, with small triangular and larger semicircular cuticular flaps, brachium with semicircular cuticular flaps, a distal patch of prickles a tiny naked seta and a single tuft of finesetae at base of terminal claw (calamus). Distal region of claw bearing two rows ofdenticles, proximal region with three pairs of serrated membranes. Maxilliped (Figure60F) chelate, indistinctly segmented, proximal segment pedunculate; corpus maxillipedis robust bearing small stout spine on distal margin and small triangular cuticularflaps; myxal area expanded into large receptacle to accommodate claw of opposablesegment. Shaft bearing two setae: one near midpoint on lateral convex margin and theother adjacent to a strip of membrane along concave distal margin. Claw (Figure 60Fdetail) unciform with reduced subquadrangular cuticular expansion producing a verysmall lateral shield.First four pairs of legs biramous with three-segmented endopods, three-segmented exopods and two-segmented sympods. All basipods with short lateral slenderseta; first basipod bears additional distomedial sshort slender seta. Ventral surfaces ofall four legs bearing triangular and semicircular cuticular flaps. Armature of rami as follows:Leg one Exopod 1-0 1-0 III Endopod 0-0 0-0 IILeg two Exopod 1-0 1-0 Ill Endopod 0-0 0-0 IILeg three Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg four Exopod 1-0 1-0 III Endopod 0-0 0-0 ILeg one (Figure 61 B) exopod reduced; exopodal setae small, stout and denticulated, endopodal setae unilaterally denticulated with elongate triangular cuticular flapsnear bases. Exopod two (Figure 61 C) elongate; first segment long with triangular cuticular flaps along lateral margin and one enlarged, distal papilliform seta, second segment smaller with papilliform seta, third segment armed with three slightly more elongated papilliform setae. Leg two endopod (Figure 61 C) with two unilaterally denticulated setae on terminal segment and three elongate, triangular cuticular flaps near bases.Legs three and four (Figure 61 D); setae short and denticulated on terminal segments.Terminal segments of exopod of leg four (Figure 61E) and endopod of leg four (Figure61F) not as elongate as leg three with smoother setae on exopod of leg four. Leg five96(Figure 61 G) elongate, distally bearing three slender setae plus one seta arising dorsally from the base; lateral surface with semicircular and triangular cuticular flaps. Leg six(Figure 61 H) represented by three short stout spines near oviducal opening.Male: UnknownComments: Predictably, Eudactyilna vaquetillae shares many characteristicswith other mobu lid-infecting species, Eudactylina diabolophila and Eudactylina oliveri.The long legs, giving these species an ant-like appearance, the reduced lateral shieldon the claw of the maxilliped, the relatively reduced exopods and elongated éndopodsof legs one and two, the relatively straight five- or six-segmented first antenna with relatively reduced auxiliary spines on the third or fourth segment, the relatively elongatedcaudal rami bearing six setae, the two rows of thick denticles found on the distal half ofthe second maxilla, the transverse palm of the maxilliped coupled to the short extensionof the myxa resulting in a reduced aperture, separate these species from their remaining congeners. Undoubtedly, close phylogenetic relationships exist among species ofthis complex.Eudactylina vaquetillae is distinguished from other species of this complex andall other congeners by the globose, mammiform setae located on the exopod of leg two,the unusual and irregular orientation of the very large semicircular cuticular flaps on thecaudal rami and the very elongate leg five.REMAINING UNOBTAINABLE NOMINAL SPECIESAs previously stated, Eudactylina now consists of 38 nominal species. Five ofthem, (E. carchariaeglauci Hesse, 1884, E. mustelilaevis Hesse, 1884, E. sqautinaeangeli Hesse, 1884, E. puriensis Tripathi, 1956, and E. mobuli Hameed et al, 1990)have not been sufficiently described to be recognized and are considered speciesinquirendae. Yamaguti (1963) includes E. versicolor Wilson, 1913 in the genus.Strangely enough, the only eudactylinid featured in Wilson (1913) is Nemesis versicolor. Thus, E. versicolor is presumably a lapsus calami due to Yamaguti’s transcriptionalerror. E. rachelae and E. complexa have been relegated to synonomy (see Kabata,1979), as has E. doilfusi and E. spinhfera herein, bringing the number of accepted taxawithin the genus to 30.For the sake of completeness and cohesiveness for future reference, this section97is a brief (alphabetical) account of the females of the uncertain species above and theremaining species that were not available for this revision of Eudactylina.Eudactylina alata Pillal, 1968 was described from Rhynchobatus sp. fromnear Kerala, India. This species is relatively well described and exhibits many unique ifnot bizarre characteristics. The first free thoracic somite immediately posterior to thecephalothorax is greatly enlarged with lateral aliform expansions overlapping the majority of the following somite. The second segment of the second antenna bears threestout spines or processes, and the prehensile claw of the first antenna appears to bebifid.Eudactylina bicornis Hameed et al, 1990 was described from the smooth hammerhead, Sphyrna zygaena (Linnaeus,1 758) near Trivandrum, India. The illustrationsare recognizeable as Eudactylina, but the fine detail needed for specific identification islacking.Eudactylina breviabdomina Pearse, 1952 was originally reported from the black-tip shark, Carcharhinus limbatus (Valenciennes, 1839) from the Gulf of Mexico nearTexas. I examined the old, colorless, flattened specimen preserved on a slide andcould not use it for the current purposes. The original description also lacks sufficientdetail.Eudactylina brevicauda Hameed et al, 1990 described from gills ofRhynchobatus djiddensis (Forsskal, 1775) from near Cape Comorin, India. Despite thespecific name bestowed upon it, this species stands out amongst its congeners due tothe presence of very long posteriorly directed extensions of the cephalothorax.Illustrations are insufficient for comparison of systematically important fine detail.Eudactylina chelata Hameed et al, 1990 was collected from gills of thewhitecheek shark, Carcharhinus dussumieri (Valenciennes, 1 839). The authors claimthis species is unique within the genus due to the modification of the terminal segmentof the endopod into a chela on legs three and four. Again, the ilustrations make it difficult to distinguish the exact nature of their claim, however it appears there is a largecurving spine on that segment.Eudactylina carchariaeglauci Hesse, 1883 was reported from the blue shark,Prionace glauca (Linnaeus, 1758) from the French Atlantic. Inadequate description relegates this to a species inquirendum (see Kabata, 1979).Eudactylina lancifera Pillai, 1968 was reported from gills of the sawfish, Pristissp. and Rhynchobatus sp. from Kerala, India. This species possesses a long medianinterpodal stylet extending from the basipod of leg three, hence the specific name. Italso exhibits what appears to be two instead of the typical single seta near the midpoint of the shaft on the maxilliped and along the distal medial margin of the myxal area98of the maxilliped. These latter two traits are unique within the genus if they truly doexist.Eudactylina minuta T. Scott, 1904 was recently redescribed by Kabata (1979)from the gills of the stingray Dasyatis pastinaca (Linnaeus). The fine illustrations allowthe researcher to easily identify this species and as always keen attention is paid to thefine detail. Because I was not able to obtain specimens of this parasite, this specieswas not included in this analysis. This species has also been reported from the rough-tail stingray Dasyatis centroura (Mitchill), and from Dasyatis pastinaca (Linnaeus,1758), both from Tunisian waters (Mediterrranean) (Essafi and Raibaut, 1977).Eudactylina mobuli Hameed et al, 1990 was described from MobuladiabolusSmith, 1943 (=Mobula kuhlii (Valenciennes in Muller and Henle, 1841)). Although theillustrations appear unrealistic, the elongated legs unmistakeably alert one to the similarity of this species to the other mobulid-infecting eudactylinids. The two-segmentedmodified exopod of leg two is very atypical for this genus. Unfortunately, the fine detailis lacking and since correct identification of mobulids is not an easy task, this specieswas not included in the analyses.Eudactylina musteilaevis Hesse, 1884 was considered a species inquirendumby Kabata (1979) due to insufficient description. This parasite was originally describedfrom gills of the smooth-hound shark, Muste/us Iaevis Linck, 1790 (=Mustelus mustelus(Linnaeus, 1758)). One wonders if subsequent records of E. insolens (resdescribedherein) from this host and from the blackspotted smooth-hound, Mustelus mediterraneus (Quignard and Capape, 1972) (=Mustelus punctulatus Risso, 1826) from thesame geographic locality represent the same parasite species.Eudactyilna parva Castro and Baeza, 1991 was recently described fromthe gills of the skate Sympterygia brevicaudata Cope, 1877 from Antofagasta, Chile.This appears to be a rather non-descript species. It does possess what appears to bea four-segmented first antenna, two large claw-like setae at the distal margin of the thirdsegmet of the first antenna, a medium length spiniform process on both second andthird segment of the second antenna, four rows of serrated membranes along the distalportion of the claw of the second maxilla, a subquadrangular lateral shield on the clawof the maxilliped, denticulated setae of exopods three and four, setae on the first exopod bearing lateral serrated membranes, and a truncate medial seta on the terminalsegment of the modified second exopod. All these characteristics should place thisspecies in with the other species of Eudactylina infecting batoids (see following cladisticanalyses).Eudactylina puriensis Tripathi, 1962 was described from gills ofRhynchobatus djiddensis from Pun, India. This description allows one to recognize the99organism as Eudactylina but little else. The general habitus does resemble E. lanciferathat Pillal (1 968) described from the same host genus. Interestingly, male E. puriensispossess two posteriorly-directed cephalothoracic extensions. These same attributes arealso shown to be shared by the male of E. alata described by Pillai (1968), again fromthe same genus of host. It would appear this confused and insufficient descriptionshould relegate this taxon to a species inquirendum.Eudactylina rhinobati was described by Raibaut and Essafi (1979) from gills ofthe shovenose guitarfish, Rhinobatos rhinobatos (L., 1758) and Rhinobatos cemiculusGeoffrey, 1817 both from southern Tunisia. The description suggests this species isclosely related to the other rhinobatid-infecting eudactylinids described herein; allspecies show similarities in structures of the caudal rami and in the two-segmentedendopods on some if not all thoracic legs.Eudactylina spinula Pearse, 1950 parasitizes the sand devil, Squat/na dumerilLesueur, 1 81 8. This species could not be used in this analysis due to it being curled upand mounted on a slide. Kabata (1979) mentions E. spinula is unmistakably differentthan E. acuta which parasitizes squatinids on the European side of the Atlantic.Eudactylina squatinaeangeli Hesse, 1883 exists as a species inquirenda due tothe insufficient description originally provided by Hesse (1883) (see Kabata, 1979).This parasite was originally reported from the angelshark, Squatina angelus Blainville,1816 (=Squatina squat/na (Linnaeus, 1758). One wonders if this does not representEudactyilna acuta, a common parasite of this host, found along European and northern African continental shelves.Eudactylina valei Nunes-Ruivo, 1956 was reported from the dusky smoothhound, Mustelus can/s (Mitchill, 1815) from Angola, and from the spiny dogfish,Squalus acanthias Linnaeus, 1758, from southwest Africa.Eudactylina vile/al Nunes-Ruivo, 1956 was originally found on the little gulpershark, Centrophorus uyato (Rafinesque, 1810), and on the longnose spurdog, Squalusfernandinus Molina, 1782 (=Squalus b/a/n v/I/el (Risso, 1826)) both members of theSqualea (see Shirai, 1992b), from off the coast of Angola. Essafi and Raibaut (1977)collected this species from the blackmouth catshark, Pristiurus melanostomus (=Ga/eusmelastomus Rafinesque, 1810) from the western Mediterranean, and off the coast ofFrance. The latter two species of Eudactylina, though both adequately described wereleft out of the analysis to maintain the standardized interpretations generated by a single illustrator/author.100PHYLOGENETIC ANALYSISCLADOGRAM CONSTRUCTIONA phylogenetic analysis was conducted for the 28 species of Eudactylinarevised herein. Deets and Ho (1988) generated a cladogram (Figure 62) and host-summary cladogram (63) of the Eudactylinidae. The outgroup used herein was composedof the supposed sister taxon Eudactylinodes and at times members of their siSter dadenamely, Eudactylinella, Carnifossorius, and Eudactyilnopsis (Figure 62; see Deets andHo, 1988 for details). 75 characters (see Appendix A for data matrix and definition ofcharacters) were analyzed using the heuristic Tree-Bisection and Reconnection (TBR)algorithm from the phylogenetic computer program PAUP (Phylogenetic Analysis UsingParsimony), version 3.OS (developed by Dr. David Swofford, Museum of NaturalHistory, Smithsonian Institution, Washington, D.C.). The most parsimonious tree forEudactylina (Figure 64) had a tree length of 239, a consistency index of 0.77 (maximum value = 1.00), a retention index of 0.88 (maximum value = 1.00), and an F- ratioof 0.0589 (maximum value=0). Due to the large number of characters, it became problematical mapping them back on the tree, therefore change and/or synapomorphy listsmay be obtained from the author.The tree posits that one species E. aspera is the sister taxon to the remainingspecies in the genus. The next node separates the tree into two major lineages, onedade is composed of the E. diabolophila - E. insolens group, while the other dade iscomposed of the remaining 18 species.Since heuristic methods do not guarantee finding the most parsimonious tree(see Swofford, 1991, for a discussion on global versus local optima), nine species ofEudactylina were then selected in order to employ the Branch and Bound algorithmwhich is capable of identifying all most parsimonious trees in PAUP. This analysis waspursued as a check or test of the general phylogenetic framework revealed from theinitial heuristic TBR method. Hence, the selection of these nine species required thissubset to span across the cladogram, and to preferably represent parasites of majorsupraspecific host taxa (i.e., Triakidae, Carcharhinidae, squalids, squatinids, pristiophorids, and batoids in order to generate a general parasite-derived phylogeny forthese systematically more inclusive host taxa. The 9 species chosen to fulfill these systematic needs were: E. acanthii, E. chilensis, E. epaktoiampter, E. acuta, E. pristiophori,E. myliobatis, E. insolens, E. push/a and, E. pollex.101A phylogenetic analysis was conducted for the 9 aforementioned species ofEudactylina. 55 characters (see Appendix B for data matrix and definition of characters) were analyzed using the Branch and Bound algorithm. The most parsimonioustree for the subset of Eudacty//na on supraspecific host taxa (Figure 65) had a treelength of 102, a consistency index of 0.88 (maximum value = 1.00), a retention index of0.88 (maximum value = 1.00), and an F- ratio of 0.0642 (maximum value=0). Again,change and/or synapomorphy lists may be obtained from the author if the reader wishes to map character state changes back on to the tree.The resultant cladogram is composed of two major lineages. The smaller dadecomposed of three species reveals E. insolens to be the sister taxon to the clde composed of E. pus//Ia and E. pollex. The other dade composed of the remaining sixspecies places E. acanthll as the sister taxon to the remaining species which sortthemselves out into two distinct clades. The first group is composed of E. chilensis andE. epaktolampter The remaining dade appears quite closely related and derived relative to the other species is this analysis. This group is composed of E. acuta, which isthe sister taxon to the remaining two species, E. pristiophori and E. myliobatidos.PARASITE-DERIVED HOST CLADOG RAMSIn an attempt to reconstruct the history of this association between species ofEudactylina and their elasmobranch hosts and to infer possible phylogenetic relationships of the host taxa, the parasite cladogram was recoded by the additive binary coding technique (O’Grady and Deets, 1987), and a host by parasite data matrix was created (Table I). Treating the parasites as characters and the phylogeny of the species as acharacter state tree was formally introduced by Brooks (1981). Accordingly, the most-parsimonious reconstruction from the data describes the evolution of the host-parasiteassociation.The phylogenetic analysis conducted from the recoded species of Eudactylinaby host matrix (Table I) resulted in a single most-parsimonious tree (Figure 66). TheTBR generated tree had a tree length of 55, and a consistency index with a maximumvalue of 1.00.The parasite-derived host cladogram postulates an unresolved group composedof Chiloscyllium, Sphyrna, Rhizoprionodon, and two Carcharhinus species (all sharingE. aspera) to be the sister group to the rest of the tree. The next node separates thetree into two major clades. The smaller complex enveloped by Manta birostris and102Mustelus asterias, is composed of carcharhiniforms and a closely related group of highly derived batoids. Specifically, an unresolved dade composed of the generaGaleorhinus and Mustelus both members of the Triakidae exist as the sister group to adade containing one lineage housing the genera Carcharhinus and Sphyrna, andanother dade with the tiger shark, Galeocerdo cuvier which in turn is the sister taxonto a group of highly derived epipelagic tropical rays, the rhinopterids and mobulids.Although at first this appears a very unlikely phylogeny for the hosts in question,a partial dismantling of the tree suggests otherwise. First, if one can apply a naivehypothesis to this chronicled pattern (see O’Hara, 1992 for an interesting discussion onthe use and misuse of evolutionary chronicle and narrative), two distinct (arid believable) patterns emerge. If a horizontal transmission or colonization event occurred withthe emergence of the rhinopterids in the lower Eocene (Eocene=35-55 MY) (Maisey,1984) from some carcharhinid parasitizing eudactylinid, as the cladogram suggests,then we are left with two separate or independent phylogenetic hypotheses ( a carcharhinid dade and a batoid dade) to inspect. The carcharhinid dade now shows thetriakid dade composed of Galeorhinus and Mustelus spp., as the sister group to thedade which now posits Galeocerdo cuvier as the sister taxon to the dade housing anunresolved polytomy of Carcharhinus plumbeus, C. acronotus, and C. obscurus whichin turn is the sister group to the Sphyrna (hammerheads) dade with these nested relationships (Sphyrna tiburo (Sphyrna lewini, Sphyrna mokarran)). These relationshipsbetween the Triakidae, Galeocerdo, Sphyrnidae, and Carcharhinidae are congruentwith those hypotheses presented by Maisey (1984b) and most recently by Compagno(1988). The relationships of the three sphyrnids revealed by their parasitic copepodsshows the same pattern as the dladogram of Sphyrnidae offered by Compagno (1988)in his monumental treatise on the Carcharhiniformes. The colonized batoid dade positsthat the two species of Rhinoptera (cownose rays) is the sister group to the dade composed of Manta which itself is the sister group to the (Mobula tarapacana (Mobulajapanica, Mobula thurstoni)) dade. Again, these relationships are congruent with thephylogenetic relationships of this closely related subset of rays set foreward by Nishida(1990), except the parasites show more resolution between the three species of Mobulaand the single species of Manta. Nishida (1990) is left with an unresolved polytomybetween the taxa used in his analysis: Manta birostris, Mobula japan/ca, Mobulalucasana (=Mobula thurstoni), and Mobula diabolus (=M. kuhili), which is often amisidentified M. thurstoni (cf. Notarbartolo-di-Sciara, 1987).The remaining dade contains taxa spanning from Squalus acanthias toUrolophus hal/en. Fascinatingly, this portion of the parasite-generated host phylogenyproposes the monophyly of the squaloids, squatinids, pristiophorids and batoids. This103corroborates the revolutionary findings of Shirai (1992a, b) in which he proposed a radically new systematic framework for squaloids and related taxa, the Squalea andHypnosqualea.The basal dade of this portion of the parasite generated host phylogeny is represented by the spiny dogfish, Squalus acanthias (Squalidae), the next branch containsthe lantern sharks (Etmopteridae). The next node up the tree mirrors the relationshipsof the supraspecific taxa comprising Shirai’s Hypnosqualea, which contains threespecies of angel sharks, Squatina, a singles species of sawshark, Pristiophorus, and22 species of batoids or Rajiformes, hierarchically arranged as follows: (Squatina(Pristiophorus, Rajiformes)).The batoid dade is characterized by a major dichotomy. The first dade is composed primarily of members from the Rajoidei plus two species of electric rays,Torpedo. This rajoid dade contains one completely unresolved polytomy of eightspecies of Raja and two species of Torpedo. Since, these ten species of rays all possess the same parasite Eudactylina s/mills, any additional Eudactylina-derived hostresolution is impossible. This complex is the sister group to a small group composed oftwo species of Rhinobatos which is the sister group to two species of Raja. It is surprising to see some species of Raja more related to Rhinobatos than to the other speciesof Raja. This incongruence may be due to the author’s inability to find and/or discriminate more characters or character states in order to resolve these inconsistencies. It isalso possible, as has been realized by others that some minor incongruencies (such asthe aforementioned paraphyletic parasite derived host relationships of Raja versus themonophyletic relationships which supposedly distinguish a taxon) in host and associatecladograms might be more apparent than real. Recent advances (software not available to the author at this point in time) comparing “host and associate” trees (i.e. genetrees and species trees, host trees and parasite trees and, organism trees and areas)generate a single hypothesis called a reconciled tree. This hypothesis which maximizesthe amount of codivergence (shared history) between the associated, represents thecombined host and associate tree and makes explicit the cost of a strict cospeciationhypothesis (Page, 1994). Future studies involving these rival methods with these datashould provide added insight regarding the historical association of this host - parasitesystem.The remaining and most apical dade of the cladogram is strictly composed ofmyliobatoids. The first subclade contains 4 species of Myliobatis. The other subcladecontains 3 myliobatoid genera that are hierarchically arranged as follows: (Urolophus(Dasyatis (Gymnura))).The phylogenetic analysis conducted from the recoded subset of nine species of104Eudactylina by host matrix (Table II) resulted in a single most-parsimonious tree (Figure67). The Branch and Bound generated tree had a tree length of 17 and a consistencyindex with a maximum value of 1 .00 This cladogram supports the relationships of thesupraspecific host taxa revealed in the initial analysis containing all 28 recoded speciesrevised herein. Additionally, with the serendipitous removal of the supposed colonization (horizontal transfer) event of the rhinopterid- mobulid dade, the putative relationships of the four carcharhiniform taxa used in this analysis break down into two distinctclades. One dade contains Galeorhinus galeus and various species of Mustelus assister groups, both members of the Triakidae. The other dade contains Galeocerdocuvier and Sphyrna mokarran, two of the largest carcharhinoids. The remainder of thetree once again shows the very interesting monophyly (the Squalea of Shirai, 1992a, b)of the squaloids, squatinids, pristiophorids and, batoids. Again, Squalus acanthiasbranches off first becoming the sister taxon to the remainder of the squalean dade.The next dade composed of shark-like squalids contains Etmopterus pusillus andAculeola nigra both members of the bioluminescent Etmopteridae. The relationships ofthe remaining three taxa confirm the relationships uncovered by the heuristic searchusing the TBR algorithm. This dade is composed of Squat/na squat/na, the sister taxonto the final dade containing Pristiophorus and Myliobatis, further corroborating thevalidity of Shirai’s (1 992a, b) Hypnosqualea.HISTORICAL BIOGEOGRAPHYHistorical biogeography is completely reliant on phylogenetically accurate systematics. Describing the distributional relationships of a taxon is useless, unless itsmembers constitute a monophyletic group (Futuyma, 1986). Cladistics can provideoriginal hypotheses on the history of the continents by means of vicariance biogeography. This rests on the postulate that allopatric speciation is due to the origin of naturalbarriers (e.g. the breakup of Pangaea), so that the phylogeny of the monophyleticgroups under study is a reflection of the geological history of the areas they occupy.Vicariance biogeography offers the advantage of hypotheses about the history of areasthat can be independently tested with geological data, without noise from intervening,narrative, ad hoc hypotheses. Thus, it can suggest to geologists inconsistenciesbetween the reported biogeographical patterns and plate tectonic models (Janvier,1984).105Fortunately, two monophyletic groups of hosts the angeisharks, Squatina andthe bat rays, Myliobat/s appear to be parasitized by monophyletic subsets ofEudactylina (Figure 66).The 3 species of Squatina, are held together as a monophyletic unit by the parasites Eudactyl/na tuber/fera, Eudactyl/na aphiloxenous, and Eudactyl/na acuta. Whatdoes the parasite-derived host and area summary-cladogram (Figure 68) tell us aboutthe possible evolutionary history of this subset of angelsharks, and land masses?First, the summary-cladogram posits that Squat/na armata (refer to discussion sectionof Eudactyilna aph/loxenous for competing ideas regarding the synonymy of S. armataand S. californica) is the sister taxon to the dade housing S. californica and S. squatina.Nothing in the literature is available for comparison regarding those specific relationships. However, the cladogram suggests two possible vicariant events, represented bythe nodes in the cladogram, were responsible for the differentiation of ancestral stockinto these three descendants. Fossils recognizeable as Squatina have been found inJurassic period deposits (Maisey, 1984), pushing their divergence time as far back as140-1 80 MY during the Mesozoic era. Assuming an intimate association was alreadyestablished between Eudactylina and Squat/na is interesting and I believe quite likely.Phylogenetically congruent host - parasite patterns found between holocephalans andelasmobranchs with the Kroyeriidae (Deets, 1987) may reflect a very ancient copepodchondrichthyan association and co-divergence event. This possibly occurred in the lateto post Devonian with the emergence of the Chondrichthyes approximately 400 MY. Inany case, the first node separates the eastern South Pacific (S. armata) from the eastern North Pacific (S. californica) plus eastern North Atlantic and Mediterranean (S.squat/na). This apparent Gondwanaland- Laurasia distribution is likely the result of theTethys Seaway separating North and South America in the late Jurassic appràximately160 MY (Haq, 1984). Another concurrent mid-Jurassic event, the opening of the NorthAtlantic began approximately 160-1 65 MY (Windley, 1984). Perhaps it is this latterevent that is represented by the node uniting the eastern North Pacific and easternNorth Atlantic plus the Mediterranean. Thus, a possible explanation for the speciationpatterns of this subset of Squat/na interpreted from the summary cladogram would positan initial separation of eastern Pacific ancestral stock into southern and northern cornponets with the opening of Central America. The Tethys Seaway must have allowedsome of the northern population to migrate far enough East to eventually find themselves rifted away with western Europe during the evolution of the North Atlantic.Future collections of Eudactylina from the remaining nine or ten species of Squat/nafound worldwide, would be a fascinating study and test of the aforementioned scenario.The 4 species of Myl/obatis, are held together as a monophyletic unit by the par-106asite s Eudactylina h ornbosteli, Eudactyilna indivisa, Eudactylina myliobatidos, andEudactylina nykterimyzon. What does the parasite-derived host and area summarycladogram (Figure 69) tell us about the possible evolutionary history of this subset ofbat rays, and their associated coastal land masses? The summary-cladogram positsthat Myliobatis sp. is the sister taxon to the dade housing M. californicus which is inturn the sister taxon to M. chilensis and M. peruvianus. The literature is devoid of dataregarding those specific myliobatid relationships. However, the cladogram posits threepossible speciation events represented by the nodes in the dladogram, responsible forthe differentiation of ancestral stock into these four descendants. The earliest fossilsrecognizeable as Myliobatis are from Tertiary deposits (Maisey, 1984b), postulatingtheir latest time of emergence occurred during the Eocene epoch 35-55 MY. This veryrecent emergence would place all the continents nearly in their present position (seeWindley, 1984; Figure 11 .3 a-h), and would make a vicariant interpretation of the relationships of the myliobatid hosts and their respective associated land masses impossible. Is their any way to infer a much earlier emergence time, independent of the relationships revealed by the parasite-derived summary-cladogram? I believe so. IfNishida’s (1990) Dasyaticloida (Urolophidae plus Dasyatididae) is the sister taxon to hisMyliobatidoidea (Gym nuridae plus Myliobatididae), then these groups share a commonnode or a common point of divergence in space and time. Although, paleontologicaldata is lacking for the Gymnuridae (butterfly rays), there is a record of a few lateCretaceous teeth which have been referred to dasyatids (Case, 1978). Additionally,there appears to have been a rapid diversification of stingrays towards the end of theCretaceous; the group may primitively be represented by the extinct Cyclobatis (upperCretaceous. Lebanon; Capetta, 1980) which approaches recent dasyatid myliobatoidsbut still maintains uncertain systematic status (Maisey, 1 984b). Hence, it seems likelythe Dasyatidoidea and Myliobatidoidea diverged in the Cretaceous, and Myliobatis ispossibly much more ancient than what the current paleontological data base hasuncovered. Working with these assumptions, telling the tree with an accomodating tectonic history is now possible. The first branch leads to an unidentified sp of Myliobatisliving in the Indian Ocean (Mozambique Channel) off Madagascar. This node may represent the incipience of the South Atlantic with the separation of South America andAfrica during the mid- Jurassic approximately 160 MY. Some reconstructions suggestMadagascar might have been located more southerly than its current position, therebybeing in relatively close proximity to the tip of South America. Additionally, the southerntip of South America may have been slightly tucked around the southern tip of southernAfrica (see Windley, 1984). Perhaps continued separation of these two continents andconcurrent expansion of the South Atlantic carried away and separated those parts of a107formerly contiguous population of Myliobatis in that southern region. The next majorevent represented by the following node on the cladogram appears to once again represent the separation of the northern and southern hemispheres (eastern North Pacificand eastern South Pacific) due to the opening of Central America by the TethyanSeaway approximately 160 MY. The final node separates two eastern South Pacificcountries, Chile and Peru from one another, sharing Myliobatis chilensis but withMyliobatis peruvianus exclusive to Chile. This final node is difficult to assess withoutany obvious potential past vicariant events or any strong geological landmarks to referto. Note that E. mdivisa and E. myliobatidos may be synonymous. Although small differences were found between the two parasite species it is possible a larger samplemay find synonymy a better choice in the future. The author prudently leaves them withtheir own taxonomic integrity in this revision, but wonders how unique their two myliobatid hosts actually are.108KRO YERIAEXTERNAL MORPHOLOGYGENERAL HABITUSThe body of Kroyeria is typically elongate and cylindrical with six distinct tagmata (Figure 70 and 71A): the cephalothorax (consisting of the segments bearing the firstantenna, second antenna, mandible, first maxilla, second maxilla, maxilliped, and thefirst pedigerous somite bearing leg one), the well developed pedigerous somites two,three, and four (bearing biramous, trimerite legs), a greatly elongated tube-like genitalcomplex housing the gonads, and bearing the reduced fifth leg, and a multi-segmentedabdomen (posteriorly giving rise to the caudal rami).The cephalothorax comprises the somites bearing the principal appendages ofattachment for Kroyeria. The main appendages of attachment are the remarkablechelate second antenna, the slender subchelate maxilliped, and the dagger-like dorsalstylets arising dorsolaterally along the posterior margin of the cephalothorax, from within the posterior sinuses. Additionally, large paired interpodal stylets arising from swimming legs two, three, and four (stylets usually reduced on leg one) (Figures 72A-72D)undoubtably function as brakes with regards to the upstream orientation of this parasiteon carcharhiniform gills (see Benz and Dupre, 1987).The major articulation of the body exists between the third free thoracic somiteand the genital complex.The genital complex of the female bears the reduced fifth leg (leg six is neverfound), and the genital complex of the male bears reduced legs five and six. Theabdomen of the male is composed of three segments, while the abdomen of thefemale exists in various states of indistinctness ranging from one to three segments.Again, this seems to indicate that the “missing” abdominal segments are not beingincorporated into the genital complex but are being suppressed or becoming less distinct due to vague segmental boundary areas (sutures less scieritized?).Many of the previous functional and anatomical comments mentioned in the section regarding the appendages of Eudactylina apply to Kroyeria and need not berepeated in the following discourse.109CAUDAL RAMUSThe caudal rami (Figure 71 C) originate terminally from the posteriormost abdominal somite. They are rather generalized in their appearance. The six setaearising from the distal region are similarly rather generalized in their structure, thoughall homologous elements have the ability to exhibit the slender pinnate state to a nakedstout state with intermediate character states exhibited by different species. The flatlamelliform shape of the ramus might allow it to function as a rudder as suggested byKabata and Hewitt (1971), for the Caligidae. Additionally, the more derived claw-likesetae when present on certain species of the upstream oriented Kroyeria, may functionto brake the parasite from slipping back and off the gill filament.DORSAL AND INTER PODAL STYLETSThe dorsal stylet (Figures 70, 71A and 71B) is a novel structure in parasiticcopepods. Other parasitic copepods possess posteriorly-directed cephalothoracicexpansions such as in female Eudactylina brevicauda Hameed et al, 1990, and maleEudactylina alata Plllai, 1968. In the monotypic Jusheyus Deets and Benz, 1987 dorsal spines arise from a thick, dorsal scierotized bar along the posterior margin of thecephalothorax. However, Kroyeria is the only genus in which these styliform processes(arising from within the posterior sinuses of the cephalothorax) are articulated. Thearticulation of this structure appears to be due to a complex ball and socket joint.Observations on living specimens reveal that the stylets have the ability to rotate freelyin all directions. Undoubtably, these structures are wedged into the secondary lamellae of the host’s gills securing the parasite in its upstream orientation (Figure 70). It hasbeen found that for Kroyeria carchariaeglauci Hesse, 1879, on the blue shark, Prionaceglauca (Linnaeus, 1758), 80 percent of individuals were attached to the secondarylamellae and the remaining 20 percent were found in the excurrent water channelsclinging to the interbranchial septa (Benz and Dupre, 1987).Dorsal stylets differ between the species. They may occur as sweeping, elongate, lissome stylets as in Kroyeria sphyrnae Rangnekar, 1957, as stout, bluntprocesses as in Kroyeria dispar Wilson, 1932, as slightly curved spines vith a flangedterminus as in Kroyeria branchioetes sp. nov., or possessing a deeply incised bifid tipas seen in Kroyeria longicauda Cressey, 1970. Hence, they are helpful characters foridentification.With the exception of Lewis’ (1 966b) discussion on the possibility of the interpo110dal stylets giving rise to the sternal furca of Dissonidae, Trebiidae and Caligidae, theorigins and homologies of dorsal and interpodal stylets have never been critically discussed. During this revision, an interesting event recurred with each dissection of theavailable species in this genus, which may shed some insight on the homology of theseunique structures. Whenever the maxillipeds were carefully dissected from thecephalothorax, the dorsal stylets became disjoined from the cephalothorax and wereremoved in conjunction with the maxillipeds. This structural complex of maxillipeds,scierites, and dorsal stylets is illustrated in Figure 83A. The maxillipeds are united by aheavily sclerotized interpodal bar. Dorsally, the base of the maxillipeds appear to articulate with a complex scleritized ring dorsolaterally giving rise to the articulated dorsalstylets.Maxillipeds are appendages of the first or anteriormost thoracic somite that havebeen incorporated into the cephalosome thus becoming a cephalothorax during theprocess of cephalization (see Huys and Boxshall 1991, Kabata, 1979, and Schram1986). Crustaceans are metameric organisms (see Barnes, 1984), therefore differentstructures having the same segmental origin are said to be serially homologous. Thus,the maxilliped is serially homologous not only to the remaining thoracic appendages butalso to the cephalic appendages, for all evolved from originally similar segmentalappendages. Interestingly, all non-reduced thoracic appendages (maxillipeds and legs)possess paired scleritized styliform processes.Not unlike the external cuticular structures such as setae, appendages, processes, and the like, other cuticular structures such as sclerites or scierotized bars or rodshave serial homologues. Hence, we should be able to use this type of information intracing morphological homologies.The thoracic legs are connected by an interpodal bar which gives rise to thepaired interpodal stylets (Figures 82B, 83A, and 83B). Although the interpodal styletsare not articulated, there are some soft, joint-like areas at the junction of the leg and theinterpodal bar. The interpodal bar anteriorly butts up against a large sclerite ring notassociated with an appendage. Anterior to this is a small gap before the pattern repeatsitself with legs united by an interpodal bar giving rise to paired interpodal stylets. Thisbar anteriorly butting up against a large non-appendage associated sclerite ring and soforth. Upon inspecting the complex of sclerites associated with the maxilliped (Figure83B), one can see the interpodal bar of the first leg with its typically reduced interpodalstylets anteriorly butting up against a non-appendage associated ring (as with the legsmentioned above), albeit not complete. This is followed anteriorly by a large gap, andthen another interpodal bar uniting the maxilipeds. This serially repeating pattern ofsclerites and appendages suggests that the interpodal stylets and the dorsal stylets111found in Kroyeria are one and the same. This is an economical explanation forthe origination of these novel structures. One must only hypothesize a single evolutionary eventgiving rise to paired, styliform, interpodal thoracic processes for their presence to beexplained on all thoracic appendages on non-reduced thoracomeres (thoracic legs fiveand six are often absent ). Perhaps a homeotic mutation, known in arthropods, whichcauses all or part of a segment to develop in a manner inappropriate to itself but inapproximate conformity to the normal development of some other segment (see Arthur,1984), could explain the manifestation of an interpodal stylet associated with a maxilliped (the dorsal stylet).FIRST ANTENNAThe first antenna of Kroyeria (Figure 71 D) is indistinctly seven- or eight-segmented. Assuming similar (homologous) innervation exists here as seen in other siphonostomes (see Kabata, 1979), this appendage has chemosensory and tactile functions.The apical segment bears 13 setae (12 terminal, 1 sub-terminal) and one aesthete. Dueto differential fusion of segments amongst species within the genus, the details regarding specific armature on each segment will be covered in taxonomic descriptions.SECOND ANTENNAThe principle attachment organ for Kroyeria is the extraordinary four-segmented,chelate second antenna (Figure 71 E). The heavily scleritized, indistinctly divided firstand second segments form a base allowing great freedom of movement (Kabata, 1979,Deets, unpublished observations of living specimens). The third segment forms the corpus of the chela, its distal end greatly produced and terminally expanded forms a receptacle to receive tip of the terminal segment or claw. The receptacle can be quite expansive when possessing membranous extensions of the cuticle as in Kroyeria longicaudaCressey, 1970 (Figure 93E), or simply a small indentation barely large enough toaccommodate the tip of the opposable claw as in Kroyeria dispar Wilson, 1935 (Figure85F). Likewise, the tip of the claw as in Kroyeria longicauda Cressey, 1970 (Figure93E) may possess membranous cuticular expansions giving it a cup-like appearancesimilar to the receptacle which typically houses it, alternatively, the tip may exist smoothand unornamented as in Kroyeria dispar Wilson, 1935 (Figure 85F). Additionally, theproximal area of the claw is typically armed with a pair of spines as in Kroyeria cresseyiDeets, sp.nov. (Figure 79F), or a set of three spines as in Kroyeria longicauda Cressey,1970 (Figure 93E). Different combinations and states of these characters make the112second antenna a valuable taxonomic and phylogenetic discriminant.MANDIBLE AND ORAL CONEThe mandible, with a dentiferous distal end (Figure 74G), uniramous, subcylindrical, is typically siphonostome. It appears to be of two parts. Their boundaries demarcated by a proximal suture. The dentiferous margin bears from seven to ten teeth, withsome species exhibiting teeth uniform in size (Figure 74G) and other species with different-sized teeth (Figure 93F), reminiscent of the primary and secondary teeth in theLernaeopodidae/Sphyriidae/Tanypleuridae complex.The oral cone (Figures 81 H and 891) consisting of anterior labrum and posteriorlabium house the mandibles. The labrum typically bears distolateral patches of pricklesand terminal membranes, the labium is equipped with two rows of prickles along the lateral surface and a terminal membrane. This structure being quite uniform throughoutthe genus was not utilized for taxonomic purposes.FIRST MAXILLAThe first maxilla (Figure 71G) located adjacent to the oral cone and mandible is abiramous appendage composed of a relatively elongate endopod and smaller exopod.Both the exopod and endopod are tipped with two setae. Setae may occur as naked orpinnate depending on the species.SECOND MAXILLAThe second maxilla of Kroyeria is a large brachiform appendage (Figure 71 H),consisting proximally of a heavily scleritized lacertus and distally of a robust brachium.The orifice of the maxillary gland is present near the base of the lacertus as is the previously undescribed (probably unnoticed) basal process. The basal process in somespecies may approach half the length of the second maxilla. The brachium is typicallyarmed with two contiguous patches of densely packed prickles. Distal to these patchesat the base of the claw is a tuft of long fine setae. The most terminal component is theclaw which may or may not represent a third segment. It is a robust, curving structure,typically armed along the lateral surfaces with lamelliform membranes and a pricklymembrane along the convex surface. No specific function for the second maxitla ofKroyeria has yet been observed.113MAXILLIPEDThe maxilliped (Figure 71 I) is a subchelate structure. The corpus appears to betwo-segmented. The subchela is not divided into a proximal shaft and distal claw as inmany siphonostomes. A minute slender seta is present near the distal end of the subchela. A membranous flange is present along the distal margin of the corpus in somespecies. Additionally, a series of three transverse cuticular flanges occur on the corpusof Kroyeria dispar Wilson, 1935 (Figure 86A) and Kroyeria longicauda Cressey, 1970(Figure 931).LEG ONEThe first thoracic leg (Figure 72A) pair is connected by an interpodal bar. As previously mentioned, interpodal stylets arise from the interpodal bar. Interpoda! stylets ofthe first thoracic leg are always reduced in relation to those of thoracic legs two, three,and four. The sympod is composed of the proximal coxa and distal basis. The coxausually bears two strips of membrane, although in a few species only one or none wereobserved. The basis similarly bears two strips of membrane, one lateral seta, and onedistomedial seta. The first leg is always biramous, composed of a lateral exopod andmedial endopod. Both the exopod and endopod are trimerite throughout the genus.The first (proximal) segment of the exopod bears a row of setules along themedial margin, a distomedial pinnate seta, a distolateral seta, and a smooth and / orpectinate membrane along the lateral edge. The second segment possesses the samecharacteristics except the distolateral seta is absent in some species. The third segment shares similar characteristics to the first two segments and bears one small lateralmost seta, one elongate slender seta occurring in various states (see detailedspecies descriptions), and four long pinnate setae.The first endopodal segment bears a single distomedial pinnate seta, a distolateral membrane, and a row of setules along the lateral margin.The second endopodal segment in most species has a row of setules along thelateral edge and in some species a series of triangular denticulations connected by awebbing of membrane. Under both light microscopy and scanning electron microscopy(unpublished data and Oldewage unpublished data), these denticulations or teeth foundon some endopodal segments appear to be thickened, fused, or fortified regions of themembrane that typically run along that lateral margin. Under close examination, themembranous webbing running along these teeth appear to fuse with the teeth orendopodal denticulations. Hence, both the membrane and the teeth or endopodal den114ticulations appear to be one in the same. Additionally, in cases where these endopodaldenticulations or teeth are absent, the typical membrane is present. Typically this segment is devoid of pinnate distomedial setae but in Kroyeria dispar Wilson, 1935 fromthe tiger shark, Galeocerdo cuvier (Peron and LeSeuer, 1822), two pinnate setae arepresent.The third or terminal endopodal segment from the first leg simUarly exhibitsmembranous denticulations or a smooth membrane and the fringing row of setules wasnot always observed. Six long, pinnate setae are found on this segment throughout thegenus. Very minute pectinate membranes reminiscent of those present in the Caligidae(see Kabata, 1979), are present at the setal bases (of some leg pairs) of some species(possibly most) but are clearly seen only with scanning electron microscopy.LEG TWOThe second thoracic legs (Figure 72B) are united by an interpodal bar whichgives rise in the majority of species to well developed interpodal stylets. The exceptionsare Kroyeria caseyl Benz and Deets, 1987 on the night shark, Carcharhinus signatus(Poey, 1868), Kroyeria dispar Wilson, 1935, and Kroyeria papillipes Wilson, 1932 bothparasitic on the tiger shark, Galeocerdo cuvier (Peron and LeSeuer, 1822). The coxaand basis are well delimited with the basis distally bearing two well developed membranes, and a single lateral seta.The first segment of the second exopod typically bears a medial row of setules,pinnate seta, a distolateral slender seta, and a lateral smooth or pectinate membrane.The second segment is similar to the first with the lateral slender seta absent in somespecies. The third segment similarly bears a smooth or pectinate membrane along thelateral margin and seven pinnate and variously modified slender setae.The first segment of the endopod bears a distomedial pinnate seta, a lateralmembrane, and a lateral fringe of setules. The second segment generally bears a lateral fringe of setules, membranous denticulations in some species, and the atypical presence of pinnate setae on the distomedial edge in Kroyeria dispar Wilson, 1935. The terminal segment harbors six pinnate setae.LEG THREEThe third thoracic legs (Figure 720) are connected by an interpodal bar possessing large interpodal stylets with the exception of K. caseyl, K. dispat and K. papillipes.The coxa is unarmed, but a lateral seta and two distal membranes are found on the115basis.The proximal segment of the exopod typically bears a medial fringe of setules, adistomedial pinnate seta, a lateral slender seta, and a smooth and / or pectinate membrane. The second segment is similar to the first, with the lateral slender seta absent incertain species. The terminal segment similar to the previous two segments bears fourelongate pinnate setae and three variously modified slender setae.The first segment of the endopod is equipped with a lateral fringe of setules, adistolateral membrane, and a single distomedial pinnate seta. The second segmentmay possess membranous denticulations, a medial pinnate seta, or a medial fringe ofsetules depending on the species. The third, or terminal, segment shares similar attributes with the preceding segments and generally bears four pinnate setae. However, inK. caseyl and K. dispar, there are three pinnate setae, one slender seta, and anotherpinnate seta for a total of five setae.LEG FOURThe fourth thoracic legs (Figure 72D) as in the previous three are connected byan interpodal bar which gives rise to interpodal stylets which are well-developed exceptin K. caseyl, K. dispar and K. papillipes. The sympod is composed of an unarmedcoxa and a basis with a single lateral seta and two membranes along the distal edge.The first exopodal segment bears a medial fringe of setules, a single distomedial pinnate seta, a single distolateral slender seta, and a smooth and / or pectinate membrane flanking the lateral margin. The second segment is similar to the first with exception of the absence of both the fringing setules on the medial edge and the distolateralslender seta in some species. The terminal segment differs from these two segmentsby possessing four pinnate setae plus three variously modified setae.The first segment of the endopod bears a lateral membrane, a lateral fringe ofsetules, and a single distomedial pinnate seta. The second segment bears a single distomedial pinnate seta and may or may not possess lateral membranous denticulationsand fringing setules. The terminal segment generally bears two pinnate setae plus onevariously modified seta. K. disparis an exception bearing two pinnate setae, one slender seta, and one more pinnate seta, as is K. papillipes bearing three pinnate setae.LEGS FIVE AND SIXThe fifth leg (Figure 81J) is located approximately 1/2 to 2/3 the length of thegenital complex down the lateral side of the genital complex and is rarely found.116However, in species where it is known it is a uniramous appendage consisting of foursetae. A sixth leg does not appear to exist.In the males, the fifth and sixth legs (Figure 73A) are found on the genital complex. The fifth and sixth leg both setiform are represented by four and two setae respective ly.LIFE HISTORYGENERAL DESCRIPTIONThere have been few published attempts of culturing Kroyeria, or descriptiveaccounts of life history stages other than the adult and first nauplius.The first report of the nauplius accompanied the first description of this genus byvan Beneden (1853) for Kroyeria lineata, the type species. Carli and Bruzzone (1973)were able to hatch first-stage of the nauplius 60 minutes after the egg was shed fromthe egg strand of Kroyeria carchariaeglauci Hesse, 1878. The most recent descriptionof the first nauplius was offered by Benz and Deets (1986), and illustrated the threenaupliar appendages, the uniramous first antenna, the biramous second antenna, andthe biramous mandible. Also shown were the two dorsal ocelli of the tripartite naupliareye (the ventral ocellus was not shown), and the two well developed filiform balancerson the posterior end.It would not be surprising if Kroyeria exhibited a holoxenous life-cycle similar tothat demonstrated by Cabral, et al (1984) in Lernanthropus kroyeri, from the percichthyid (temperate bass) Dicentrarchus labrax (see Raibaut, 1985 for a general life history review of different parasitic copepod taxa).REPRODUCTIONCopulation and reproduction probably occurs in a manner similar to that inEudactylina, but no reports or observations have been published. I have not seen members of this genus in the presumed copulatory embrace.117HOST-PARASITE RELATIONSHIPSDELETERIOUS EFFECTS / FEEDINGAs previously stated, Kroyeria attach themselves to the secondary lamellae ofthe gill primarily with their clasping chelate second antenna, and secondarily with theirarticulate posterolaterally oriented dorsal stylets and the ventroposteriorly directed interpodal stylets (Figure 70). Benz and Dupre (1987), have shown that 80 percent of all K.carchariaeglauci Hesse, 1879, attach themselves in an upstream-oriented fashion tothe secondary lamellae on the gills of its favored host, the blue shark, Prionace glauca(Linnaeus, 1758). The remaining 20 percent were found clipped on to the soft tissue inthe underlying excurrent water channels. The dorsal stylets and interpodal stylets withtheir supposed braking function probably allow Kroyeria increased mobility in its environment by not having to rely entirely on the second antennae for its security. It is speculated that the second antennae may be used to reach out and align itself upstreamand possibly crawl with them, assuming the stylets have the ability to hold the parasitein place, as suggested by Figure 70.I have not witnessed gill tissue pathologies induced by Kroyeria in the carcharhinform hosts I have inspected over the years. During microscopic examination,many specimens of Kroyeria still had tissue from the secondary lamellae grasped intheir chelate second antennae. Hence, some damage is occuring to the respiratory surfaces of the host. In situ, the copepods are reddish, suggesting these parasites feed atleast in part on blood. Blood would be easily accessible from the secondary lamellaesince respiratory blood sinuses are only one epithelial cell thick in this region (Benz,1984). With up to 1,250 individuals per host as reported for K. carchariaeglauci onPrionace glauca (Benz and Dupre, 1987) some physiological effects on the host sharkwould be expected.The specific feeding mechanics have yet to be observed for any gill dwellingcopepod, but morphological evidence (from scanning electron microscopy, Oldewage,unpublished) suggests that it is similar to that of caligids as described by Kabata (1974,1979).A dentiferous ridge, the strigil, appears to be present along the inner edge of thelabium (Oldewage, unpublished SEM micrographs,). The strigil possibly saws away atthe epithelial cells, while the mandibles equipped with their dentiferous margins, maycontinue the maceration process and then convey the host tissue into the buccal cavity.Patches of prickles along the distolateral region of the labrum and the two rows of spin118ules flanking the lateral surfaces of the labium may anchor the oral cone to the feedingsite.SPECIFICITYAlthough the literature suggests a few species such as K. ilneata and K. carchariaeglauci have the ability to infect a broad range of hosts, my personal collectionsover the last 1 3 years, suggest that host specificity is the general rule for the species inthis genus. One problem that undoubtably beleaguers this host-parasite system is themorphological conservatism that both Kroyeria and its hosts, the Carcharhiniformesexhibit. Hence, host and/or parasite may have been misidentified and the .apparentbroad host range of these species may be artifactual.With the exception of the mesoparasitic Kroyeria caseyl Benz and Deets, 1986,which embeds approximately 80% of its body into the interbranchial septa of its hostCarcharhinus signatus (Poey, 1868), Kroyeria typically attach by the chelate secondantenna to the gills (secondary lamellae).Microniche specificity and the functional morphological requirements associatedwith it has only recently been examined in parasitic copepods of elasmobranchs (seeBenz 1980, 1992; Benz and Adamson, 1990; Benz and Dupre, 1987). Reports ofmicroniche have typically not been given in sufficient detail (e.g., skin, gill, or branchiallamellae) to assess the ecological or morphological significance of the association.When collecting eudactylinids or kroyeriids from branchial lamellae, I havenoticed that genera that possess fully chelate attachment organs, such as the secondantenna of Kroyeria or the maxilliped of Eudactylina or Eudactylinodes, secure themselves primarily to the secondary lamellae of their host. On the other hand, Nemesis,attaches itself by surrounding the efferent branchial arterioles near the gill filaments’free distal tips with its large subchelate maxillipeds (Benz and Adamson, 1990), amicrofiche quite unlike that occupied by its fully chelate allies.SYSTEMATIC ACCOUNTGenus Kroyeria van Beneden, 1853Kroyeriidae: Female. Cephalothorax covered by well demarcated dorsal shieldDorsal stylets arising from posterior sinuses of cephalothorax. Three pedigerous segments between cephalothorax and genital complex. Genital complex composed of pedi119gerous somites five and six, together constituting more than 50% of length of body.Abdomen one- to three-segmented. Caudal ramus lamelliform bearing six setae distally.First antenna indistinctly seven- or eight-segmented, terminal segment bearingone aesthete and thirteen slender setae. Second antenna four-segmented and chelate;third segment distally produced into a receptacle to accommodate claw of terminal segment. Mouth tube siphonostome. Mandible of two parts, distal end dentiferous bearingfrom seven to ten teeth. First maxilla biramous with both endopod and exopod bearingtwo apical setae. Second maxilla brachiform, two- possibly three-segmented (includingclaw). Maxilliped subchelate, subchela not divided into shaft and claw. Legs onethrough four biramous and trimerite. Leg five when found represented by four setae.Male: Similar to female; abdomen three-segmented. Legs five and six setiformand represented by four and two setae respectively.TYPE-SPECIES: Kroyeria lineata van Beneden, 1853COMMENTS: Previous to this account, the literature contained references to 19nominal species (see Kabata, 1979 for review). An additional description of anunnamed male by Capart (1953) is devoid of illustrations making correct identificationdifficult. The description suggests affinity with K. papillipes, and this possibility is furthersuggested by the fact that Capart’s material came from the tiger shark, Galeocerdocuvier(Peron and LeSueur, 1822), the principal host to K. papillipes. Three species (K.acanthiasvulgaris Hesse, 1879, K. galeivulgaris Hesse, 1884, and K. scyliicaniculaeHesse, 1879) have been insufficiently described to be recognized and are treated asspecies inquirendae. K. trecai Delamare Deboutteville and Nunes-Ruivo, 1953 wasnever fully described and remains a nomen nudum. K. aculeata (Gerstaecker, 1854)and K. sublineata Yamaguti and Yamasu, 1959 have been relegated to junior synonymsof K. lineata van Beneden, 1853. This revision resurrects K. elongata Pillai, 1967 fromsynonymy, and treats it as a valid species. Five species new to science, K. branchiocetes, K. cresseyi, K. decepta, K. procerobscena, and K. rhophemophaga aredescribed herein.Kroyeria consists of the 16 species illustrated and phylogenetically analyzedherein, plus two unobtainable species for this current effort bringing the total number ofaccepted species to 18. As in the previous section, the unobtained species will bereviewed at the end of the following taxonomic account.The systematics of Kroyeria has suffered in the past from insufficient attention tomorphological detail that can be used as specific discriminants (Kabata, 1979).Additionally, this genus is superficially morphologically conservative, and also difficult to120distinguish.The major host taxon for Kroyeria, is the Carcharhiniformes (see Raibaut, 1982).The latest revision of this host group was by Compagno (1988). He estimates that thislargest group of living sharks comprises nearly 60 percent or 200 species of the approximately 350 known shark species. This information coupled to the apparently highdegree of host fidelity exhibited by Kroyeria, suggests (as is true of Eudactylina) thereare many species yet to be discovered in the genus.Kroyeria branchiocetes sp. nov(Figures 71-73)Material examined. Several females (on loan from Dr. Z. Kabata, Pacific BiologicalStation, Nanaimo, Canada) collected by Dr. Paperna, University of Israel, from the gillsof the grey reef shark, Carcharhinus amblyrhynchos (Bleeker, 1856) from the Red Sea.Female holotype (USNM 266533) and 3 female paratypes (USNM 266534) depositedat the United States National Museum of Natural History.Etymology: The specific name branchiocetes is derived from the greek Branch/a,meaning gill and oecetes an inhabitant, referring to the typical gill-dwelling nature ofthis rather attractive, albeit nondescript species.DescriptionFemale (Figure 71A)Overall length in dorsal view approximately 3.8 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 71 A and 71 B) extending posteriorly to nearly 30 % down the length of the thirdfree thoracic somite, stylets curving slightly inward and distolaterally bearing a flange-like cuticular expansion. Three free thoracic somites with overlapping terga. Genitalcomplex cylindrical, constituting 60 % of total body length. Posterolateral corners of latter bearing oviducal openings. Abdomen indistinctly three-segmented. Caudal ramus(Figure 71C) lamelliform, longer than wide with medial fringe of setules, distally bearingfour pinnate and two semipinnate setae.First antenna (Figure 71 D) indistinctly eight-segmented, armature (base to apex)as follows: 10, 1, 5, 2, 3, 1 1, 1 2 +1 aesthete. Second antenna (Figure 71 E) chelateand prehensile, apparently four-segmented. Proximal two segments heavily sclerotized121in such a way as to suggest relatively unrestricted movement capabilities. Third segment forming corpus of chela, extending into a rigid arm distally expanded into a membranous receptacle to accommodate tip of fourth segment. Latter forming heavily scierotized robust claw, bearing two prominent setae proximally and similarly expanded intoa membranous receptacle distally. Mandible (Figure 71 F) of two parts (only distal portion illustrated), dentiferous margin with nine teeth, tiny apical tooth followed by onelarge, two small, two large, and three small. First maxilla (Figure 71G) biramous; endopod longer bearing two apical elongate, naked setae; exopod shorter bearing twoshort, naked setae. Second maxilla (Figure 71H) brachiform; lacertus heavily sclerotized with elongate basal process arising from near base. Brachium with two largepatches of prickles and a tuft of fine, long setae near base of claw; claw bearing lateralmembranous lamellae with small prickles scattered upon convex surface. Maxilliped(Figure 711) subchelate; corpus two-segmented; subchela not divided into shaft andclaw, distally uncinate and bearing a single small, slender seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and one or two distomedial membranes: first basipod bears additional distomedial pinnate seta; first coxopod bears additional distolateral membrane.All four interpodal bars bearing interpodal stylets; interpodal stylets of leg one verysmall. Lateral fringe of setules on each endopodal segment, medial fringe of setules oneach of first exopodal segment. Armature of rami as follows (Arabic numerals denotefully pinnate setae, Roman numerals conditions diverging from that state):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod I-i 1-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 72A) bearing distolateral membrane on first (proximal)segment; pectinate lateral membrane on segments two and three. Segment three withfour pinnate setae, one elongate slender seta bearing a lateral membrane, and onesmall naked seta. Endopod of leg one (Figure 72A) with distolateral membrane on firstsegment; segment two with four to five (only four shown) endopodal denticulations;segment three with four to six (only four shown) endopodal denticulations. Exopod ofleg two (Figure 72B) similar to leg one, except second segment bears additional seta(bilaterally bearing membranes), and third segment with four pinnate setae, one semipinnate seta with setules along the medial edge and a membrane along the lateral, oneslender seta bearing a membrane along the lateral edge, and one seta bearing mem122branes on both lateral and medial edges. Endopod of leg two similar to leg one, exceptfive to six endopodal denticulations (five shown) are present on the second segment;five endopodal denticulations on the third segment. Exopod of leg three (Figure 72C)as in leg two, except seta adjacent to lateralmost seta bilaterally bears membranes(unilaterally in leg two). Endopod of leg three (Figure 71C) with six and five endopodaldenticulations on segments two and three respectively; segment three with four pinnatesetae. Exopod of leg four (Figure 72D) as in leg three. Endopod of leg four (Figure 72D)with seven and five endopodal denticulations on segments two and three respectively;segment three with two pinnate setae and one bilaterally bearing serrated membranes.Fifth leg (not shown) represented by four setae.Male: (Figure 73A)Overall length in lateral view approximately 2.8 mm. Cephalothoracicappendages and swimming legs similar to those of female. Genital complex bearingfifth and sixth legs represented by four and two setae respectively. Dorsal stylet (Figure73B) shorter and more stout than that of female with a hyaline flange along the proximalmedial margin. Caudal ramus (Figure 73C) more elongate than that of female, setulesfringing medial margin; six distal setae (two semipinnate, four pinnate).Comments: Kroyeria branchiocetes is the first kroyerid reported from the greyreef shark, Carcharhinus amblyrhynchos (Bleeker, 1856). This non-descript parasiteresembles K. cresseyl, K. ilneata, K. rhophemophagus, and K. triakisae, in possessingonly two slender setae on the claw of the second antenna. It can be distinguished fromthese species by the presence of endopodal denticulations on segments two and threeof all four swimming legs. Interestingly, all four of the aforementioned parasites lackingthe complete set of endopodal denticulations and possessing only two (not the morecommon condition of three) slender setae on the claw of the second antennae arefound on various hosts of the family Triakidae. Kroyeria branchiocetes is found onCarcharhinus amblyrhynchos, a member of Carcharhinidae as opposed to Triakidae.Kroyeria carchariaeglauci Hesse, 1879(Figures 74-76)Syn: Kroyeria gracilis Wilson, 1932, (see Delamare-Deboutteville and Nunes Ruivo)123Material examined. Several males and females collected by George Benz, TennesseeAquarium, Chatanooga, Tennessee, U.S.A., from the gills of the blue shark, Prionaceglauca (Linnaeus, 1758) from the western North Atlantic; numerous males and femalescollected from the same host species from the southern California bight near theChannel Islands and from the southern Sea of Cortez (Gulf of California) near IslaCerralvo; a few specimens were collected from the silky shark, Carcharhinus falciformis(Bibron, 1839) near Punta Arena de Ia Ventana and Isla Cerralvo in the southern Sea ofCortez; a few specimens collected from the pelagic white tip shark, Carcharhinus longimanus (Poey, 1861) near the Revillagigedos Islands in the tropical eastern NorthPacific, Mexico.DescriptionIllustrated specimen from blue shark, Prionace glauca (Linnaeus, 1758).Female (Figure 74A, B)Overall length in dorsal view approximately 5.5 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 74A-C) extending posteriorly to approximately 60 % down the length of thesecond free thoracic somite, stylets curving slightly inward and distally bifurcating.Three free thoracic somites with overlapping terga. Genital complex cylindrical, constituting approximately 65 % of total body length. Posterolateral corners of latter bearingoviducal openings; egg strand bearing 44 eggs. Abdomen indistinctly three-segmented.Caudal ramus (Figure 74D) lamelliform, longer than wide with medial fringe of setules,distally bearing six pinnate setae (one short, one short and pyriform, and four elongate).First antenna (Figure 74E) indistinctly seven- or eight-segmented, armature(base to apex) as follows: 11 (only nine shown), 5, 2, 3, 1, 1, 13 +1 aesthete. Secondantenna (Figure 74F) chelate and prehensile, apparently four-segmented. Proximal twosegments heavily scierotized in such a way as to suggest relatively unrestricted movement capabilities. Third segment forming corpus of chela, extending into a rigid armdistally expanded into a receptacle to accommodate tip of fourth segment. Latter forming heavily sclerotized robust claw, bearing three prominent slender setae proximally.Mandible (Figure 74G) of two parts, dentiferous margin with nine teeth. First maxiMa(Figure 74H) biramous; endopod longer bearing two apical elongate, naked setae; exopod shorter bearing two short, naked setae. Second maxiMa (Figure 741) brachiform;lacertus heavily scierotized with elongate basal process arising from near base.Brachium with two large patches of prickles and a tuft of fine, long setae near base ofclaw; claw bearing paired lateral membranous lamellae with small prickles scatteredupon convex surface. Maxilliped (Figure 75A) subchelate; corpus two-segmented,124proximal segment bearing two conical processes, and proximal end of adjacent segment bearing single small, conical process; subchela not divided into shaft and claw,distally uncinate and bearing a single small, slender seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and one or two distomedial membranes; first basipod bears additional distomedial pinnate seta; first coxopod bear additional distolateral membranes.All four interpodal bars bearing interpodal stylets; interpodal stylets of leg one relativelysmall. Lateral fringe of setules on each endopodal segment, medial fringe of setules oneach of first exopodal segment. Armature of rami as follows (Arabic numerals denotefully pinnate setae, Roman numerals denote conditions diverging from that state):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod I-i 1-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 75B) bearing distolateral membranes on segmentsone, two and three. Segment three with four pinnate setae, one elongate, slender setabearing a finely serrated, lateral membrane, and one small naked seta. Endopod of legone (Figure 75B) with distolateral membrane on first segment; segment two with six toeight (only six shown) endopodal denticulations; segment three with six to seven (onlysix shown) endopodal denticulations (specimens collected from the pelagic white tip,Carcharhinus longimanus (Poey, 1861), bear nine). Exopod of leg two (Figure 75C)similar to leg one, except second segment bears additional lateral, slender seta, andthird segment with four pinnate setae, one semipinnate seta with setules along themedial edge and a membrane (smooth or finely serrated, too small for certainty) alongthe lateral edge, one slender seta bearing a membrane along the lateral edge, and onenaked, slender seta. Endopod of leg two similar to leg one, except seven endopodaldenticulations (eight in the specimens collected from the pelagic white tip) are presenton the second segment and eight to ten (ten shown) endopodal denticulations on thethird segment. Exopod of leg three (Figure 75D) as in leg two, except seta adjacent tolateralmost seta appears to be devoid of lateral membrane (unilaterally in leg two).Endopod of leg three (Figure 75D) with seven and ten endopodal denticulations on segments two and three respectively (eight are present on both segments from specimenscollected from the pelagic white tip); segment three with four pinnate setae. Exopod ofleg four (Figure 75E) as in leg three. Endopod of leg four (Figure 75E) with seven andnine endopodal denticulations on segments two and three respectively (specimens ccl-125lected from the pelagic white tip bear seven to eight on segment three); segment threewith two pinnate setae and one bilaterally bearing serrated membranes; bases of setaebearing small pectinate membranes (reminiscent of those in Caligidae). Fifth leg (seeFigures 74A and 74B) represented by four setae.Male: (Figure 76A)Overall length in lateral view approximately 4.4 mm. Cephalothoracicappendages and swimming legs similar to those of female. Genital complex bearingfifth and sixth legs represented by four and two setae respectively. Dorsal stylet shorterand more stout than that of female. Caudal ramus (Figure 76B) more elongate than thatof female, setules fringing medial margin; six distal setae (two semipinnate, four pinnate).Comments: Kroyeria carchariaeglauci Hesse, 1879 was originally describedfrom gills of the blue shark, Carcharhinus glaucus (=Prionace glauca (Linnaeus, 1758))near Brest, France in the eastern North Atlantic. It was subsequently redescribed fromfrom the same host in the Mediterranean (Delamare Debouteville & Nunes Ruivo,1953), from Japanese waters (Shiino, 1957), from off Valaparaiso, Chile (Stuardo andFagetti, 1961), from the West coast of South Africa (Kensley and Grindley, 1973), fromthe western North Atlantic and Mediterranean (Carli and Bruzzone, 1972; 1973), fromTunisian waters (Essafi and Raibaut, 1977), from the western North Atlantic (Benz,1986; Benz and Dupre, 1987), and herein from the eastern North Pacific from thesouthern Sea of Cortez, Mexico, Revillagigedos Islands, Mexico, and Channel Islands,southern California Bight.K. carchariaeglauci has also been reported from carcharhiniform hosts otherthan the blue shark. The first report of this occurred with the description of K. gracilisby Wilson (1932). He reported K. grad/is from the blue shark and brown shark,Carcharhinus milberti (Valenciennes, in Muller and Henle, 1839) (= the sandbar shark,Carcharhinus plumbeus, Nardo, 1827). Additionally, K. grad//is is considered a juniorsynonym of K. carchariaeglauci by Delamare-Deboutteville and Nunes-Ruivo (1953)and Shiino (1957). Kabata and Gusev (1966) report K. carchar/aeglauci from Eu/am/asp. from near Cocos Island, Indian Ocean but provided no illustrations. Finally, Essafiand Raibaut (1977) add questionable records of K. carchariaeg/auci inhabiting the starry smooth-hound, Mustelus aster/as Cloquet, 1821, and the smooth-hound Mustelusmustelus (Linnaeus, 1758) from France. Equally suspect, is their report of K. carchariaeg/auci from gills of the longnose spurdog, Squalus blainvillei (Risso, 1826).I have examined specimens from Dr. Roger Cressey’s personal collection from126elasmobranchs from both the Indian Ocean and Florida coast, (see Cressey, 1967 and1970) and conclude that the many unillustrated records of K. gracilis (= K. carchariaeglauci) on hosts other than blue shark, Prionace glauca (Linnaeus, 1758), pelagicwhite tip, Carcharhinus longimanus, (Poey, 1861), and silky shark, Carcharhinus falciform/s (Bibron, 1839) should be viewed with caution (see following new speciesdescriptions of K. decepta and K. procerobscena).The combined characteristics of the bifid dorsal stylet, the relative length to widthratio of the males’ caudal rami (see K. decepta), and the stout, pyriform, pinnate setaadjacent to the two elongate pinnate setae of the caudal rami, readily distinguish thisspecies from its congeners.Kroyeria Casey! Benz and Deets, 1986(Figures 77-78)Material examined. Two females and one male collected from the interbranchial septaof the night shark, Carcharhinus signatus (Poey,1 868) from the western North Atlantic.DescriptionFemale (Figure 77A-C)Overall length in dorsal view approximately 60 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 77A-D) very short and robust, extending posteriorly to approximately 50 %down the length of the first free thoracic somite, stylets curving inward slightly and terminating somewhat bluntly. Three free thoracic somites with overlapping terga. Genitalcomplex cylindrical, inflating distally and constituting approximately 95 % of total bodylength. Posterolateral corners of latter bearing oviducal openings. Abdomen swollen,one-segmented bearing tiny posteroventrally directed spinules. Caudal ramus (Figure77E) lamelliform, longer than wide devoid of typical medial fringe of setules, distallybearing six stout, naked, setae.First antenna (Figure 77F) indistinctly seven- or eight-segmented, armature(base to apex) as follows: 7, 2, 5, 2, 3, 1, 1, 13 +1 aesthete. Second antenna (Figure77G) chelate and prehensile, apparently four-segmented. Proximal two segments heavily sclerotized in such a way as to suggest the capablity of relatively unrestricted movement. Third segment forming corpus of chela, extending into a rigid arm distallyexpanded into a receptacle to accommodate tip of fourth segment. Latter forming heavi127ly sclerotized robust claw, bearing one elongate, somewhat blunt seta near midpoint,one tiny seta along concave margin in aperture of chela, and one proximal seta.Mandible (Figure 77H) of two parts, dentiferous margin with nine teeth. First maxilla(Figure 771) biramous; endopod longer bearing two apical elongate, naked setae; exopod shorter bearing two short, naked setae. Second maxilla (Figure 77J) brachiform;lacertus heavily sclerotized with stout basal process arising from near base. Brachiumwith two large patches of prickles and a tuft of fine, long setae near base of claw; clawvery elongate, bearing paired lateral membranous lamellae. Maxilliped (Figure 77K)subchelate; corpus two-segmented, proximal segment bearing two conical processes,and proximal end of adjacent segment bearing single small, conical process; subchelanot divided into shaft and claw, distally uncinate and bearing a single small, slenderseta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bears additional distomedial pinnate seta; first coxopod bears additional membranes. All four interpodalbars bearing small interpodal stylets; interpodal stylets of leg one smaller than others.Lateral fringe of setules on each endopodal segment; medial fringe of setules on theproximal segment of each exopod. Armature of rami as follows (Arabic numeralsdenote fully pinnate setae, Roman numerals denote conditions diverging from thatstate):Leg one Exopod I-i 1-1 11,4 Endopod 0-1 0-1 6Leg two Exopod I-i 1-1 111,4 Endopod 0-1 0-1 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1 ,I,3Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 78A) bearing distolateral membranes on segmentsone, two and three. Segment three with four pinnate setae, plus two naked setae.Endopod of leg one (Figure 78A) with distolateral membrane on first segment; segmenttwo with three to eight (only three shown) endopodal denticulations; segment three withthree to six (four shown) endopodal denticulations. Exopod of leg two (Figure 78B) similar to leg one, except third lateral most seta is semipinnate with setules along the medial edge and a finely serrated membrane along the lateral edge, and two lateralmostseta bilaterally bearing smooth or finely serrated membranes (too small for certainty).Endopod of leg two similar to leg one, with three to six endopodal denticulations (threeshown) present on the second segment and four to six (four shown) endopodal denticulations on the third segment. Exopod of leg three (Figure 77C) as in leg two. Endopod128of leg three (Figure 78C) with three to five and four to five endopodal denticulations onsegments two and three respectively (three and four are shown, respectively); segmentthree bears one medial pinnate seta followed laterally by one stout seta, and three elongate pinnate setae. Exopod of leg four (Figure 78D) as in leg three. Endopod of leg four(Figure 78D) with three to five (three shown) endopodal denticulations on segment two,and two to seven (three shown) endopodal denticulations on segment three. Fifth legnot found.Male: (Figure 78E)Overall length in dorsal view approximately 3.0 mm. Cephalothoracicappendages and swimming legs similar to those of female. Genital complex bearingfifth and sixth legs represented by four and two setae, respectively. Dorsal stylet slightly more stout than that of female. Caudal ramus (Figure 78F) more elongate than that offemale, with setules fringing medial margin: six elongate distal setae (two pinnate).Comments: Kroyeria caseyl has been reported only once from the night shark,Carcharhinus signatus (Poey, 1868) by Benz and Deets (1986) from the western NorthAtlantic. Kroyeria caseyi is perhaps the most remarkable member of the entireKroyeriidae. It not only is the largest member of the family at approximately 60 mm, butit is also the only known member to date of this family to be mesoparasitic, embeddedup to 80% of its body (anteriorly) into the interbranchial septa. The extremely elongategenital complex (comprising approximately 95% of the total body length) coupled to thevery elongate claw of the second maxilla, the reduced seta in the aperture of the second antenna, the 1,1 3 formula of the terminal segment of endopod three, the inflatedone-segmented abdomen, and the very derived caudal rami devoid of the typical medialfringe of setules, and bearing stout naked setae, distinguish this species from all otherkroyeriids.Kroyeria cresseyi sp. nov.(Figures 79-80)Material examined. Several females collected from the secondary lamellae of the leopard shark, Triakis semifasciata Girard, 1854 from inshore waters off El Segundo, SealBeach, and Palos Verdes, California, U.S.A. Female holotype (USNM 266535) and 5female paratypes (USNM 266536) deposited at the United States National Museum of129Natural History.Etymology: The specific name honors my good friend and pioneer in the studies of theparasitic copepods infecting elasmobranchs. Dr. Roger Cressey, Curator of Crustacea,USNM, Smithsonian Institution, Washington D.C.DescriptionFemale (Figure 79A)Overall length in dorsal view approximately 5.0 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 79A and 79B) extending posteriorly to approximately 50 % down the length ofthe second free thoracic somite, stylets curving inward slightly with a bifid terminus.Three free thoracic somites with overlapping terga. Genital complex cylindrical, constituting approximately 66 % of total body length. Posterolateral corners of latter bearingoviducal openings. Abdomen indistinctly three-segmented. Caudal ramus (Figure 79C)lamelliform, longer than wide bearing the typical medial fringe of setules, distally bearing four elongate pinnate setae and two shorter semipinnate setae. Egg strands (Figure79D) containing six eggs.First antenna (Figure 79E) indistinctly seven- or eight-segmented, armature(base to apex) as follows: 11, 1,5, 2, 3, 1, 1, 13 (only 12 shown) +1 aesthete. Secondantenna (Figure 79F) chelate and prehensile, apparently four-segmented. Proximal twosegments heavily sclerotized in such a way as to suggest the capablity of relativelyunrestricted movement. Third segment forming corpus of chela, extending into a rigidarm distally expanded into a receptacle to accommodate tip of fourth segment. Latterforming heavily sclerotized robust claw, bearing one elongate seta along concave margin in aperture of chela, and one proximal elongate seta. Mandible (Figure 79G) of twoparts, dentiferous margin with nine (1 apical, 2 large, 2 small, 2 large, and 2 small)teeth. First maxilla (Figure 79H) biramous; endopod longer bearing two apical elongate, naked setae; exopod shorter bearing two short, naked setae. Second maxilla(Figure 80A) brachiform; lacertus heavily sclerotized with large basal process arisingfrom near base. Brachium with two large patches of prickles and a tuft of fine, longsetae (not shown) near base of claw. Claw bearing paired lateral membranous lamellae, with a unilaterally serrated membrane enveloping the latter. Maxilliped (Figure80B) subchelate; corpus two-segmented, proximal segment bearing two conicalprocesses, and proximal end of adjacent segment bearing single small, conicalprocess; subchela not divided into shaft and claw, distally uncinate and bearing a single small slender seta.130All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bears additional distomedial pinnate seta; first coxopod bears two additional membranes. All four interpodal bars bearing elongate interpodal stylets; interpodal stylets of leg one smaller thanothers. Lateral fringe of setules on each endopodal segment, medial fringe of setuleson the proximal segment of each exopod. Armature of rami as follows (Arabic numeralsdenote fully pinnate setae, Roman numerals denote conditions diverging from thatstate):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod 1-1 0-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 11,4 Endopod 0-1 0-0 4Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 80C) bearing lateral membranes on segments one,two and three. Segment three with four pinnate setae, plus two slender setae; longer ofthe two with membrane along lateral edge. Endopod of leg one (Figure 80C) with distolateral membrane on first segment; segment two with six endopodal denticulations; segment three with distolateral membrane, and six pinnate setae. Exopod of leg two(Figure 80D) similar to leg one, except third lateral most seta is semipinnate withsetules along the medial edge and a finely serrated membrane along the lateral edge,the two lateralmost setae slender and apparently naked. Endopod of leg two similar toleg one, with three to six endopodal denticulations (six shown) present on the secondsegment, and a distolateral membrane and six pinnate setae on the third segment.Exopod of leg three (Figure 80E) similar to leg two except second segment bears asmall lateral seta, and the terminal segment bears only 2 lateral setae laterally bearingserrated membranes; longer of the two semipinnate. Endopod of leg three (Figure 80E)with three to seven endopodal denticulations on segment two (four shown); segmentthree bears four pinnate setae and one distolateral membrane. Exopod of leg four(Figure 80F) as in leg two. Endopod of leg four (Figure 80F) with six to thirteen (thirteenshown) endopodal denticulations on segment two; one lateral stout seta bilaterallybearing serrated membranes, and two pinnate setae tip segment three. Fifth leg notfound.Comments: Kroyeria cresseyl along with K. branchiocetes, K. lineata, K.rhophemophagus, and K. triakos all possess second antennae with the claw armed withonly two slender setae, as opposed to three found amongst the remaining congeners.131K. cresseyl differs most notably form K. branchiocetes and K. ilneata by not possessingthe large membranous expansions found distally on the claw and the corpus of the second antennae of these two species. K. cresseyl is easily distinguished from K. triakosby possessing only four pinnate setae (plus two slender setae (one with serrated membrane and one semipinnate)) on the terminal segment of exopod three, while K. triakosbears five pinnate setae (plus one naked seta). Finally, the orbicular cephalothorax ofK. cresseyl is quite dissimilar from the distinctly subquadrangular cephalothorax of K.rhophemophagus. Additionally, K. cresseyi stands apart from this species complex inbeing the only member with a bifid dorsal stylet.As noted above, K. branchiocetes differs from these species in that it occurs inthe Carcharhinidae not the Triakidae.Kroyeria decepta sp. nov(Figures 81-84)Material examined. Several males and females collected by Dr. Roger Cressey, fromthe gills of the dusky shark, Carcharhinus obscurus (LeSueur, 1818) from the Westcoast of Florida; numerous males and females collected from the same host speciesfrom near the Revillagigedos Islands in the tropical northeastern Pacific, Mexico.Female holotype (USNM 266537) and 7 female paratypes (USNM 266538) depositedat the United States National Museum of Natural History.Etymology: The specific name decepta is derived from the Latin dec/plo, to deceive, inreference to the subtle morphological differences possessed by this species, relative toK. carchar/aeglauci, making specific identification difficu It.DescriptionFemale (Figure 81A, B)Overall length in dorsal view approximately 7.6 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 81 A, B, and 81 D) extending posteriorly to approximately 60 % down the lengthof the second free thoracic somite, stylets curving slightly inward and distally bifurcating. Three free thoracic somites with non-overlapping terga. Genital complex cylindrical,constituting approximately 66 % of total body length. Posterolateral corners of latterbearing oviducal openings. Abdomen indistinctly three-segmented. Caudal ramus132(Figure 81C) lamelliform, longer than wide with medial fringe of setules, distally bearingsix pinnate setae (two stout and four elongate).First antenna (Figure 81 E) indistinctly seven- or eight-segmented, armature(base to apex) as follows: 10, 5, 2, 3, 1, 1, 13 +1 aesthete. Second antenna (Figure81 F) chelate and prehensile, apparently four-segmented. Proximal two segments heavily scierotized in such a way as to suggest relatively unrestricted movement capabilities.Third segment forming corpus of chela, extending into a rigid arm distally expandedinto a receptacle to accommodate tip of fourth segment. Latter forming heavily sclerotized robust claw, bearing three prominent slender setae proximally. Mandible (Figure81 G) of two parts, dentiferous margin with nine teeth (2 large, 2 small, 2 large, 3 slightlysmaller). Labrum of oral cone (Figure 81H) typical of the genus. First maxilla (Figure81 I) biramous; endopod longer bearing two apical elongate pinnate setae; exopodshorter bearing two short, naked setae. Second maxilla (only claw detailed) (Figure82A) brachiform; lacertus heavily scierotized with elongate basal process arising fromnear base. Brachium with two large patches of prickles and a tuft of fine, long setaenear base of claw; claw bearing paired lateral membranous lamellae with small pricklesscattered upon convex surface. Maxilliped (Figures 82B, 83A, 83B) subchelate; corpus two-segmented, proximal segment bearing two conical processes; subchela notdivided into shaft and claw, distally uncinate and bearing a single small slender seta.[The possible homologous relationships between the interpodal and dorsal stylets’ sclerites illustrated in Figures 823, 83A, B have been discussed in the previous dorsal andinterpodal stylet section dealing with this hypothesis].All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and one or two distomedial membranes; first basipod bears additional distomedial pinnate seta; first coxopod bears two additional distolateral membranes, and a small patch of spinules. All four interpodal bars bearing interpodalstylets; interpodal stylets of leg one relatively small. Lateral fringe of setules on eachendopodal segment, medial fringe of setules on the first exopodal segment of .each leg.Armature of rami as follows (Arabic numerals denote fully pinnate setae, Romannumerals denote conditions diverging from that state):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod I-i 1-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 82C) bearing distolateral membranes on segments133one, two and three (membranes pectinate on segments two and three). Segment threewith four pinnate setae, plus two lateral setae bearing finely serrated, lateral membranes. Endopod of leg one (Figure 820) with distolateral membrane on first segment;segment two with eight endopodal denticulations; segment three with eight to nine (nineshown) endopodal denticulations (specimens of K. carchariaeglauci collected from thepelagic white tip, Carcharhinus longimanus (Poey, 1861), similarly bear nine).. Exopodof leg two (Figure 82D) similar to leg one, except second segment bears additional lateral seta, and third segment with four pinnate setae, plus one semipinnate seta withsetules along the medial edge and a membrane along the lateral edge, and two slendersetae bearing membranes along their lateral edge. Pectinate membranes are presentalong the lateral margin of segments two and three. A strip of pectin is also presentparalleling the typical membrane along the lateral margin if the first segment of bothexopod one and two. Endopod of leg two (Figure 82D) similar to leg one, except eightto nine (nine shown) endopodal denticulations (eight in the specimens of K. carchariaeglauci collected from the pelagic white tip) are present on the second segment andnine to ten (ten shown) endopodal denticulations on the third segment. Exopod of legthree (Figure 82E) as in leg two, except the two lateralmost setae appear to be devoidof lateral membrane (unilaterally in leg two). Endopod of leg three (Figure 82E) witheight to nine endopodal denticulations on segments two and nine to ten endopodal denticulations on segment three (eight are present on both segments from specimens of K.carchariaeglauci collected from the pelagic white tip); segment three with four pinnatesetae. Exopod of leg four (Figure 82F) as in leg three. Endopod of leg four (Figure 82F)with seven to eight and eight to ten endopodal denticulations on segments two andthree respectively (specimens of K. carchariaeglauci collected from the pelagic white tipbear seven to eight on segment three); segment three with two pinnate setae and onebilaterally bearing serrated membranes. Fifth leg (Figure 81J) represented by four setae(three pinnate and one naked).Male: (Figure 84A and 84B)Overall length in lateral view approximately 4.6 mm. Cephalothoracicappendages and swimming legs similar to those of female. Genital complex bearingfifth and sixth legs represented by four and two pinnate setae respectively. Dorsal styletshorter and more stout than that of female. Caudal ramus (Figure 84C) more elongatethan that of female, setules fringing medial margin; six distal setae (one stout andsemipinnate, one stout and naked, two large and two small pinnate). Leg one endopod(two most distal segments illustrated) (Figure 84D) similar to female, bearIng’ four andfive endopodal denticulations on segments two and three respectively. Endopods of134legs two, three and four similar to leg one, all bearing four to five endopodal denticulations on segments two and three.Comments: Kroyeria decepta is very similar to K. carchariaeglauci, and thisundoubtedly has led to confusion in my mind and in the literature. Having examinedspecimens of Kroyeria from Carcharhinus obscurus from both the West coast of Floridaand off the Revillagegedos Islands in the tropical eastern North Pacific, I believe thisrepresents a distinct form and have treated it herein as such. Many specific differences, albeit subtle, contribute to this decision. First, the caudal rami of male K. decepta are greatly elongated relative to that of male K. carchariaeglauci, being approximately 9.5 times the width, compared with about 6.5 times the width in male K. carchariaeglauci. The length of the genital complex of female K. decepta is approximately10.25 times its width, compared with that of C. carchariaeglauci which is only about 7.6times its width. The endopod of the first maxilla of K. decepta bears pinnate setae,these setae are naked in K. carchariaeglauci. The lateral membranes on the secondand third segments of the exopod from leg one are pectinate in K. decepta, while thoseof C. carchariaeglauc/ are thin and smooth. The two species are different in size; K.decepta is approximately 7.6 mm in total length, while K. carcharaieglauci is about 5.5mm long, or about 72% the length of the former. The length of the dorsal stylet of K.decepta is approximately 6.5 times its width, compared to that of K. carecharchiaeglauci, which is nearly 8.8 times its width. And finally, the teeth on the mandible from K.decepta exhibit alternating sizes; teeth are more uniform in size in K. carchariaeglauci.K. decepta appears to be confined to the dusky shark, Carcharhinus obscurus.Interestingly, Kabata and Gusev (1966) report K. carchar/aeglauci from Eu/am/a sp. inthe Indian Ocean. The copepod was reported to be 6.72 mm, large for that species, anda genital complex length approximately 9 times that of its width. These measurementssuggest that copepod may be K. decepta, but without examining the specimen or beingmore certain what Eulamia sp. represents, no conclusion should be drawn.Kroyeria dispar Wilson, 1932(Figures 85-86)Material examined. Several females and males (USNM 153870) collected by Dr.Roger Cressey, from the gills of the tiger shark, Galeocerdo cuvier (Peron & LeSueur,1822) from the West coast of Florida; numerous males and females (USNM 153864)135collected from the same host species from the Indian Ocean near Madagascar.DescriptionFemale (Figure 85B)Overall length in dorsal view approximately 13.1 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Cephalothorax laterally extended relative to congeners. Dorsal stylets (Figures 85B and 85C) extendingto just below posterior margin of first free thoracic somite, stylets curving slightly inwardwith blunt tips. Three free thoracic somites with non-overlapping terga. Genital complexcylindrical, constituting approximately 65 % of total body length. Posterolateral cornersof latter bearing oviducal openings. Abdomen indistinctly one- or two-segmented.Caudal ramus (Figure 85D) lamelliform, longer than wide with medial fringe of setules,distally bearing two stout semipinnate setae, two long thick pinnate setae, and twosmall slender pinnate setae; two duct-like openings (see detail) are present ventrodistally.First antenna (Figure 85E) indistinctly nine-segmented, armature (base to apex)as follows: 9, 1, 1 5, 2, 3, 1, 1, 13 +1 aesthete. Second antenna (Figure 85F) chelateand prehensile, apparently four-segmented. Proximal two segments heavily sclerotizedin such a way as to suggest relatively unrestricted movement capabilities. Third segment forming corpus of chela, extending into a rigid arm distally expanded into a smallreceptacle to accommodate tip of fourth segment. Latter forming heavily sclerotizedrobust claw, proximally bearing three prominent setae (one seta nearly half the lengthof claw and very blunt). Aperture of chela nearly circular due to strongly curving claw.Mandible (Figure 85G) of two or three parts as suggested by divisions of the sclerites,dentiferous margin with nine teeth. First maxilla (Figure 85H) biramous; endopodlonger bearing two apical elongate setae with rows of denticles; exopod shorter bearingtwo short, naked setae. Second maxilla (Figure 851) brachiform; lacertus heavily sclerotized with elongate basal process arising from near base. Brachium with two largepatches of prickles and a tuft of fine, long setae near base of claw; the latter bearingpaired lateral membranous lamellae with small prickles scattered upon convex surface.Maxilliped (Figure 86A) subchelate; corpus two-segmented, proximal segment bearingtwo conical processes; myxal region of corpus with large protuberance bearing threecuticular expansions reminiscent of the cuticular flaps in Eudactylina; subchela notdivided into shaft and claw, distally uncinate and bearing a single minute seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bears additional distomedial pinnate seta; first coxopod bears two additional membranes. All four interpo136dal bars with poorly developed (absent?) interpodal stylets. Lateral fringe of setules oneach endopoda! segment, medial fringe of setules on the first exopodal segment ofeach leg. Armature of rami as follows (Arabic numerals denote fully pinnate setae,Roman numerals denote conditions diverging from that state):Leg one Exopod I-i 1-1 11,4 Endopod 0-1 0-2 6Leg two Exopod I-i I-i 111,4 Endopod 0-1 0-2 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,1,3Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,1,2Exopod of leg one (Figure 86B) bearing distolateral membranes on segmentsone, two and three (additional pectinate strips on segments two and three). Segmentthree with four pinnate setae, plus two lateral setae bilaterally bearing membranes.Lateral short setae on all exopods with flagellate tips. Endopod of leg one (Figure 86B)with distolateral membranes on each segment. Exopod of leg two (Figure 86C) similarto leg one, except third segment with four pinnate setae, plus one semipinnate seta withsetules along the medial edge and a membrane along the lateral edge, and the two lateralmost setae bilaterally bearing membranes. Pectinate membranes paralleling thetypical membranes are present along the lateral margin of segments one, two, andthree. Endopod of leg two (Figure 86C) similar to leg one. Exopod of leg three (Figure86D) as in leg two, except pectinate membranes not observed. Endopod of leg three(Figure 86D) with only one pinnate seta on segment two and segment three bears (laterally to medially) one pinnate seta, one short seta bearing membranes followed bythree pinnate setae. Exopod of leg four (Figure 86E) as in leg three. Endopod of legfour (Figure 86E) similar to leg three except terminal segment bears one pinnate setafollowed by one short seta bearing membranes, followed by only two pinnate setae.Fifth leg (not illustrated) represented by four setae (three pinnate and one naked).Male: (Figure 85A)Overall length in lateral view approximately 7.2 mm. Cephafothoracicappendages and swimming legs similar to those of female. Genital complex bearingfifth and sixth legs represented by four and two pinnate setae respectively. Dorsal styletshorter and more stout than that of female. Caudal ramus more elongate than that offemale.Comments: Kroyeria dispar was originally described by Wilson (1935) from anunnamed shark. Since then, (see Cressey, 1967, 1970) all subsequent records have137been from gills of the tiger shark, Galeocerdo cuvier (Peron & LeSueur, 1 822).The unusually wide cephalothorax, the absence of endopodal denticulations,plus the presence of two elongate, pinnate setae arising from the medial margin of legsone and two, the spinulated / denticulated endopod of the first maxilla, and the peculiarcuticular flaps found on the myxal area of the maxilliped distinguish this species from allothers in the genus. This species shares several attributes with K. papillipes also fromGaleocerdo cuvier: short dorsal stylets, very reduced interpodal stylets, circular aperture of the second antenna, and an indistinctly nine-segmented first antenna.Kroyeria elongata Pillai, 1967Syn: KroyeriaspatulataPearse, 1948 of Pillal, 1985nec Kroyeria spatulata Pearse, 1948nec Kroyeria elongatus Fukui, 1965(Figures 87-88)Material examined. Several females (USNM 154002) collected by Dr. Roger Cressey,from the gills of the spot-tail shark, Carcharhinus sorrah (Valenciennes, 1 839) from theIndian Ocean near Madagascar.DescriptionFemale (Figure 87A)Overall length in dorsal view approximately 3.0 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 87A, C) extending into anterior quarter of free thoracic somite three, styletscurving inward with expanded distolateral portion forming a cuticular flange. Three freethoracic somites with non-overlapping terga. Genital complex cylindrical, constitutingapproximately 63 % of total body length. Posterolateral corners of latter bearing oviducal openings. Abdomen indistinctly three-segmented. Caudal ramus (Figure 87B) lamelliform, longer than wide with medial fringe of setules, distally bearing two stout setae(the longer distally pinnate, the shorter semipinnate), two thick longer pinnate setae,and two slender pinnate setae.First antenna (Figure 87D) indistinctly seven- to eight--segmented, armature(base to apex) as follows: 10, 1, 5, 2, 3, 1, 1, 13 +1 aesthete. Second antenna (Figure87E) chelate and prehensile, apparently four-segmented. Proximal two segments heavily sclerotized in such a as way to suggest relatively unrestricted movement capabilities.138Third segment forming corpus of chela, extending into a rigid arm distally expandedinto a large receptacle to accommodate tip of fourth segment. Latter forming heavilyscierotized robust claw, distally bearing membranous expansions forming a large cuticular receptacle fitting into the large receptacle of the corpus. Claw additionally beañngthree prominent slender setae proximally (middle seta shorter and blunt). Aperture ofchela elliptical due to elongated corpus and claw, reminiscent of the maxilliped inEudactylina. Mandible (Figure 87F) of two or three parts as suggested by divisions ofthe sclerites, dentiferous margin with nine teeth (1 apical, 1 large, 2 small, 2 large, and3 small decreasing in size). First maxilla (Figure 87G) biramous; endopod longer bearing two apical elongate naked setae; exopod shorter bearing two short, naked setae.Second maxilla (Figure 87H) brachiform; lacertus heavily sclerotized with elongatebasal process arising from near base. Brachium with two large patches of prickles anda tuft of fine, long setae near base of claw; the latter bearing paired lateral membranouslamellae with small prickles scattered upon convex surface. Maxilliped (Figure 871)subchelate; corpus two-segmented, proximal segment bearing three conical processes; subchela not divided into shaft and claw, distally uncinate and bearing, a singlesmall slender seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bears additional clistomedial pinnate seta; first coxopod bears two additional membranes. Interpodal barswith interpodal stylets (leg one interpodal stylet very small or absent). Lateral fringe ofsetules probably present on each endopodal segment, though not seen on all segmentsfrom specimens inspected, medial fringe of setules on the first exopodal segment ofeach leg. Armature of rami as follows (Arabic numerals denote fully pinnate setae,Roman numerals denote conditions diverging from that state):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod I-i 1-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 88A) bearing distolateral membranes on segmentsone, two and three (membranes pectinate on segments two and three). Segment threewith four pinnate setae, plus two lateral slender setae (the lateralmost seta naked, theadjacent seta bearing a membrane along lateral edge). Endopod of leg one (Figure88A) with distolateral membrane on first segment, five to six endopodal denticulationson the second segment, and three to five endopodal denticulations on the terminal seg139ment. Exopod of leg two (Figure 88B) similar to leg one, except second segment bearslateral spiniform seta, and third segment bears four pinnate setae, plus one semipinnate seta with setules along the medial edge and a membrane along the lateral edge,and the two lateralmost setae laterally bearing membranes. Endopod of leg two (Figure88B) similar to leg one. Exopod of leg three (Figure 88C) as in leg two. Endopod of legthree (Figure 88C) similar to leg two but segment three bears only four pinnate setae.Exopod of leg four (Figure 88D) as in leg three. Endopod of leg four (Figure 88D) similar to leg three except second segment medially bears pinnate seta, and terminal segment bears one stout seta bilaterally bearing short setules plus two pinnate setae.Male: not acquiredComments: Kroyeria elongata was originally described by Pillai (1967) frommilk shark, Scoliodon sorrokowah (Bleeker, 1853) (=Rhizoprionodon acutus (Ruppel,1837). PiIlai (1985) synonomized this species with K. spatulataPearse, 1948. No reaSons were given for the action, but the two species are quite distinct from another.K. elongata can be distinguished from its congeners easily by the structure of theSecond antenna alone. No other Kroyeria has such an elongated claw and corpus ofthe second antenna. These attributes give the second antenna a very elongate ellipticalaperture resulting in a general morphology that is reminiscient of that seen in thechelate maxilliped of Eudactylina. K. elongata is further distinguished from K. spatulatain that the terminus of the dorsal stylet of K. elongata is an inward curving flange, whilethat of K. spatulata is bifid (see following species description of K. spatulata). Thecephalothorax of K. elongata is subtriangular not subquadrangular as in K. spatulata.This report adds the spot-tail shark, Carcharhinus sorrah, as the second known host forthis species. Both records come from the Indian Ocean.Kroyeria gemursa Cressey, 1967(Figures 89-90)Material examined. Two paratype females (USNM 113296) collected from the gills ofthe great hammerhead, Sphyrna mokarran (Ruppel, 1837) from the Indian Ocean nearMadagascar; numerous females (USNM 153855) from the same host species fromnear Sarasota, Florida.140DescriptionFemale (Figure 89A)Overall length in dorsal view approximately 14.4 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Ventral surface ofrostrum (Figure 890) with two small spinous processes. Dorsal stylets (Figures 89A-C,E) extending near anterior quarter of free thoracic somite three, stylets relativelystraight, with a tiny bifid terminus. Three free thoracic somites with non-overlappingterga. Genital complex cylindrical, constituting approximately 73 % of total body length.Posterolateral corners of latter bearing oviducal openings. Abdomen indistinctly threesegmented. Caudal ramus (Figure 89D) lamelliform, longer than wide with medialfringe of setules along proximal half, bearing four pinnate setae distally (2 large, twosmall), and distolaterally bearing two stout semipinnate setae each with a ventromedialrow of tiny denticles.First antenna (Figure 89F) indistinctly seven-segmented, armature (base toapex) as follows: 11, 3, 1, 3, 1, 1, 1 2 +1 aesthete. Second antenna (Figure 89G) chelateand prehensile, apparently four-segmented. Proximal two segments heavily sclerotizedin such a way as to suggest relatively unrestricted movement capabilities. Third segment forming corpus of chela, extending into a rigid arm distally expanded into a smallreceptacle to accommodate tip of fourth segment. Latter forming heavily scierotizedrobust claw, proximally bearing three setae. Aperture of chela small due to stout clawand stout pollex of corpus. Mandible (Figure 89H) of two parts, dentiferous margin withnine teeth (1 apical, 1 large, 2 small, 2 large, and 3 small decreasing in size). Oralcone (Figure 891) typical kroyeriid type but with lateral patches of spinules on thelabrum much larger than those of congeners. First maxilla (Figure 89J) biramous; endopod longer bearing two apical elongate, pinnate setae; exopod shorter bearing twoshort, naked setae. Second maxilla (Figure 90A) brachiform; lacertus heavily sclerotized with elongate basal process arising from near base. Brachium with two largepatches of prickles and a tuft of fine, long setae near base of claw; the latter bearingpaired lateral membranous lamellae with small prickles scattered upon convex surface.Maxilliped (Figure 90B) subchelate; corpus two-segmented, proximal segment bearingtwo conical processes, one conical process on proximal part of main corpus; subchelaindistinctly divided into shaft and claw, distally uncinate and bearing a single smallslender seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bears additional distomedial pinnate seta. Interpodal bars with interpodal stylets (leg one interpodal styletvery small and blunt). Lateral fringe of setules present on segment one of the first141endopod and on the first and second segments of endopods two, three, and four, medial fringe of setules on the first exopodal segment of each leg. Armature of rami as follows (Arabic numerals denote fully pinnate setae, Roman numerals denote conditionsdiverging from that state):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod I-i 1-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 90C) bearing distolateral membranes on segmentsone, two and three. Segment three with four pinnate setae, plus two shorter lateralsetae (lateralmost seta with membrane along medial edge, the adjacent seta bearing afinely serrated membrane along lateral edge). Endopod of leg one (Figure 9CC) withdistolateral membrane on first segment, 28 to 30 endopodal denticulations on the second segment, and 29 to 31 endopodal denticulations on the terminal segment. Exopodof leg two (Figure 90D) similar to leg one, except second segment bears lateral seta,and third segment bears four pinnate setae, plus one semipinnate seta with setulesalong the medial edge and a finely serrated membrane along the lateral edge, onespiniform seta bilaterally bearing finely serrated membranes and a small naked seta.Endopod of leg two (Figure 90D) similar to endopod of leg one, except second segmentbears 25-32 endopodal denticulations, and segment three bears 28-33 endopodal denticulations. Exopod of leg three (Figure 90E) as in leg two, except lateral seta on second segment bears a finely serrated lateral membrane. Endopod of leg three (Figure90E) similar to leg two but segment three bears only four pinnate setae, segment twobears 10-12 endopodal denticulations, and segment three bears 15 endopodal denticulations. Exopod of leg four (Figure 90F) as in leg three. Endopod of leg four (Figure90F) similar to leg three except second segment medially bears pinnate seta, and terminal segment bears one stout seta bilaterally bearing serrated membrane plus twopinnate setae. Second and third segments bear 10-12 and 11-13 endopodal denticulations respectively.Male: not acquiredComments: Kroyeria gemursa was originally described by Cressey (1967) fromthe great hammerhead, Sphyrna mokarran from off Madagascar. Since then it has beenreported from the same host from the West coast of Florida (Cressey, 1970) and from142the Indian Ocean near Trivandrum, India (Pillai, 1985).The laterally bulging, heavily sclerotized distal region of the last segment of theabdomen, the thickened claw and thickened extension of the corpus with the resultantreduced aperture of the second antenna, the large patches of spinules on the distolateral surfaces of the labrum, and the numerous (25-33) endopodal denticulationsfound onthe second and third segments of leg one and leg two, readily distinguish this species.Kroyeria lineata van Beneden, 1853Syn: Lonchidium aculeatum Gerstaecker, 1854Lonchidium Iineatum;of Bassett-Smith (1899)Kroyeria lineata Beneden; of Brian (1906)Kroyeria aculeata Gerstaeker; of Brian (1906)Krøyeria lineata Beneden; of Wilson (1932)Krøyeria sublineataYamaguti and Yamasu, 1959(Figures 91-92)Material examined. One female (BMNH 1928.6.11.6-15); one female (BMNH191 3.9.18.250-259) both collected by Andrew Scott from the gills of the tope shark,Galeus canis Bonaparte, 1834 (= Galeorhinus galeus (Linnaeus, 1758) from the IrishSea; one female (BMNH 23.5.1975 ) collected by G.A. Boxshall from the gills of thesmooth-hound, Mustelus mustelus (Linnaeus, 1758).DescriptionFemale (Figure 91A)Overall length in dorsal view approximately 4.9 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 91A and 91B) extending near hind margin of first free thoracic somite, styletscurve sharply inward, forming an uncinate terminus. Three free thoracic somites withnon-overlapping terga. Genital complex cylindrical, constituting approximately 68 % oftotal body length. Posterolateral corners of latter bearing oviducal openings. Abdomenindistinctly three-segmented. Caudal ramus (Figure 91C) lamelliform, longer than widewith medial fringe of setules, bearing two pinnate setae distally, one distomedial pinnate seta, one distal thick semipinnate seta, and distolaterally bearing one stput semi-pinnate setae, and one slender pinnate seta.First antenna (Figure 91D) indistinctly seven- to eight-segmented, armature(base to apex) as follows: 10, 1, 5, 2,3, 1, 1, 12 +1 aesthete. Second antenna (Figure14391 E) chelate and prehensile, apparently four-segmented. Proximal two segments heavily scierotized in such a way as to suggest relatively unrestricted movement capabilities.Third segment forming corpus of chela, extending into a rigid arm distally expandedinto a large membranous receptacle to accommodate tip of fourth segment. Latter forming heavily sclerotized robust claw, bearing two prominent setae proximally, and distallyexpanded into a large membranous receptacle. Mandible (Figure 91 F) of two parts,dentiferous margin with nine teeth (1 apical, 1 large, 2 small, 2 large, and 3 smalldecreasing in size). First maxilla (Figure 91G) biramous; endopod longer bearing twoapical elongate, pinnate setae; exopod shorter bearing two short, naked setae.Second maxilla (Figure 91H) brachiform; lacertus heavily scierotized with short basalprocess arising from near base. Brachium with two large patches of prickles and a tuftof fine, long setae near base of claw; the latter bearing paired lateral membranouslamellae with small prickles scattered upon convex surface, and atypically, a large distal, subquadrangular membranous flap. Maxilliped (Figure 901) subchelate; corpustwo-segmented; subchela not divided into shaft and claw, distally uncinate and bearinga single small, slender seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bears additional distomedial pinnate seta. Interpodal bars with interpodal stylets (leg one interpodal styletvery small). Lateral fringe of setules present on all endopodal segments, medial fringeof setules on the first exopodal segment of each leg. Armature of rami as follows(Arabic numerals denote fully pinnate setae, Roman numerals denote conditionsdiverging from that state):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod 1-1 0-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i I-i 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 92A) bearing lateral membranes on segments one,two and three. Segment three with four pinnate setae, plus two lateral slender setae(lateralmost seta smaller and naked, adjacent seta bearing membrane along lateraledge). Endopod of leg one (Figure 92A) with distolateral membranes on all three segments, and devoid of endopodal denticulations. Exopod of leg two (Figure 92B) similarto leg one, except third segment bears four pinnate setae, plus one semipinnate setawith setules along the medial edge and a membrane along the lateral edge, one setalaterally bearing a membrane, and a small naked seta. Endopod of leg twa (Figure14492B) similar to endopod of leg one. Exopod of leg three (Figure 92C) as in leg two,except second segment bears a lateral slender seta. Endopod of leg three (Figure 92C)similar to leg two but segment three bears only four pinnate setae. Exopod of leg four(Figure 92D) as in leg three. Endopod of leg four (Figure 92D) similar to leg threeexcept second segment medially bears pinnate seta, and terminal segment bears onestout seta bilaterally bearing serrated membrane plus two pinnate setae.Male: not acquiredComments: Kroyeria lineata van Beneden, 1853, type species of the genus,was originally reported from tope shark, Galeus canis Bonaparte, 1834 (= Galeorhinusgaleus (Linnaeus, 1758)). Since then, a few questionable records come from hosts inthe family Carcharhinidae, such as the smooth hammerhead, Sphyrna zygaena(Linnaeus, 1758) (Cf. Wilson, 1932), the blacktip shark, Carcharhinus limbatus(Valenciennes, 1839), and the lemon shark, Hypoprion brevirostris (=Negaprion brevirostris (Poey, 1868)), (cf. Wilson, 1936), and the blue shark, Prionace glauca(Linnaeus, 1758) (cf. Rokicki and Bychawska, 1991; Kabata, 1979), the species hasbeen reported principally from tope sharks, smooth-hounds or whiskery sharks of thegenera Galeorhinus and Mustelus, of the family Triakidae. K. lineata has been reported from the tope shark, Galeorhinus galeus (Linneaus, 1758) from Belgian waters (vanBeneden, 1853 and 1861), from the Mediterranean (Claus, 1858), (Brian, 1906); fromthe Irish Sea (Scott and Scott, 1913, A.Scott, 1929), and from off England (LeighSharpe, 1933). K. lineata has also been reported from the smooth-hound Mustelusmustelus (Linnaeus, 1758), (= Mustelus equestrias, see Compagno, 1984b), from theAdriatic Sea (Valle, 1880), the North Sea (Boxshall, 1974), and the Mediterranean offTunisia (Essafi and Raibaut, 1977). The species has also been found on the starrysmooth-hound, Mustelus aster/as Cloquet, 1821 and Mustelus punctulatus Risso, 1826(= M. mediterraneus according to Compagno (1984b)), and off Tunisia in theMediterranean (Essafi and Raibaut, 1979). Finally, the relegation of K. sublineataYamaguti and Yamasu, 1959 to synonymy with K. lineata by Kabata (1979) extends thehost and geographic range to include the starspotted smooth-hound, Mustelus ManazoBleeker, 1854 from Japanese waters (Inland Sea).Kabata (1979) suggested that K lineata may be a synonym of the incompletelydescribed Lonchidium aculeatum Gerstaeker, 1854, collected from Galeorhinus galeus,in the eastern North Atlantic. Brian (1906) and Delamare Deboutteville and NunesRuivo (1953) agreed with this synonymy. Evidence accumulated over the years indicates that G. galeus is one of the preferred hosts for K. lineata, and supports this synonymy.145K. lineata is the only species in the genus that has endopods without endopodaldenticulations and a second antenna bearing only two prominent setae on the proximalregion of the claw. Additionally, no other Kroyeria has the distal membranous extensions near the tip of the claw of the second maxilla. The relatively short, sharply incurving dorsal stylets coupled with the angular cephalothorax, aid in specific identification ofthis parasite.Kroyeria longicauda Cressey, 1970(Figures 93-95)Material examined. One paratype female (USNM 128497) collected from the gills of theblacktip shark, Carcharhinus limbatus (Valenciennes, 1839) from Sarasota, Florida;numerous females and a male (USNM 128496) collected by Dr. Roger Cressey, fromthe same host species from near Sarasota, Florida; and a few females (USNM154003) collected from the gills of the spinner shark, Carcharhinus brevipinna (Mullerand Henle, 1839) collected by Dr. Roger Cressey from Nosy Be Island, nearMadagascar in the Mozambique Channel.DescriptionFemale (Figure 93A)Overall length in dorsal view approximately 3.5 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 93A and 93B) extending near anterior quarter of third free thoracic somite,stylets slightly curving inward with a deeply bifid terminus, lateral tine approximately20% the length of the other. Three free thoracic somites with non-overlapping terga.Genital complex cylindrical, constituting approximately 65 % of total bod’ length.Posterolateral corners of latter bearing oviducal openings. Abdomen indistinctly threesegmented. Caudal ramus (Figure 93C) lamelliform, longer than wide without medialfringe of setules along proximal half, but with a lateral cuticular flange not a membraneas represented by Cressey (1970) or Pillai (1985), bearing five pinnate setae and onestout, plumose seta.First antenna (Figure 93D) indistinctly seven- to eight-segmented, armature(base to apex) as follows: 10, 1,5,2,3, 1, 1, 13+1 aesthete. Second antenna (Figure93E) chelate and prehensile, apparently four-segmented. Proximal two segments heavily sclerotized in such a way as to suggest relatively unrestricted movement capabilities.146Third segment forming corpus of chela, extending into a rigid arm, distally expandedinto a large receptacle to accommodate tip of fourth segment. Latter forming heavilysclerotized robust claw, distally expanded into a large membranous receptacle similarto corpus, and bearing three prominent setae proximally. Aperture of chela small dueto the large membranous expansions of both claw and corpus. Mandible (Figure 93F)of two parts, dentiferous margin with nine teeth (1 apical, 1 large, 2 small, 2 large, and3 small decreasing in size). First maxilla (Figure 93G) biramous; endopod longer bearing two apical elongate, naked setae; exopod shorter bearing two short, naked setae.Second maxilla (Figure 93H) brachiform; lacertus heavily sclerotized with basal processarising from near base. Brachium with two large patches of prickles and a tuft of fine,long setae near base of claw; the latter bearing paired lateral membranous lamellaewith small prickles scattered upon an inflated convex surface. Maxilliped (Figure 931)subchelate; corpus two-segmented, myxal area bearing three crescent-shaped, membranous, cuticular flaps reminiscent of those in Eudactylina; subchela not divided intoshaft and claw, distally uncinate and bearing a single small, slender seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bears additional distomedial pinnate seta. Interpodal bars with interpodal stylets (leg one interpodal styletvery small and blunt). Lateral fringe of setules present on segments one and two of allendopods, medial fringe of setules on the first exopodal segment of each leg. Armatureof rami as follows (Arabic numerals denote fully pinnate setae, Roman numerals denoteconditions diverging from that state):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod I-i 1-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 94A) bearing pectinate lateral membranes on segments one, two and three. Segment three with four pinnate setae, plus two lateral slender setae (lateralmost seta naked, the adjacent seta semipinnate and bearing a membrane along lateral edge). Endopod of leg one (Figure 94A) with distolateral membraneon first segment, five to six endopodal denticulations on the second segment, and fourendopodal denticulations on the terminal segment. Exopod of leg two (Figure 94B)similar to leg one, except second segment bears lateral seta , and third segment bearsfour pinnate setae, plus one sernipinnate seta with setules along the medial edge and afinely serrated membrane along the lateral edge, and two slender seta bearing a mem147brane alonge their lateral edge. Endopod of leg two (Figure 94B) similar to endopod ofleg one, except second segment bears six to seven endopodal denticulations, segmentthree bears four endopodal denticulations. Exopod of leg three (Figure 94C) as in legtwo, except lateral seta on second segment bears a lateral membrane. Endopod of legthree (Figure 94C) similar to leg two but segment three bears only four pinnate setae,segment two bears five endopodal denticulations, and segment three bears threeendopodal denticulations. Exopod of leg four (Figure 94E) as in leg three. Endopoci ofleg four (Figure 94D) similar to leg three except second segment medially beas pinnateseta, and terminal segment bears one stout seta bilaterally bearing smooth membranesplus two pinnate setae. Second and third segments bear three to four and threeendopodal denticulations respectively. Leg five composed of four setae.Male: (Figure 95A)Overall length in lateral view approximately 2.1 mm. Cephalothoracicappendages and swimming legs similar to those of female. Genital complex bearingfifth and sixth legs represented by four and two pinnate setae respectively. Dorsal stylet(Figure 95B) more stout than that of female, and similarly bearing a small lateral tine.Caudal ramus (Figure 950) more elongate than that of female, lacking setules fringingmedial margin; six distal setae (one stout and semipinnate, one stout and naked, andfour slender and pinnate).Comments: Kroyeria longicauda was originally described by Cressey (1970)from the blacktip shark, Carcharhinus limbatus from off Sarasota, Florida. It has beenreported from this host from the Indian Ocean near Kerala, India (Pillai, 1985). Thisreport adds the spinner shark, Carcharhinus brevipinna (Muller and Henle, 1839) fromthe Mozambique Channel to the host and geographic range of this parasite.Interestingly, both the spinner shark, Carcharinus brevipinna and the blacktip shark,Carcharhinus limbatus are members of Garrick’s (1967) “C. limbatus group” andGarrick’s (1982) “C. limbatus-amblyrhynchoides group” (see Compagno, 1988). Thepresence of K. longicauda is consistent with the hypothesized close relationshipbetween these species.The lateral tine on the deeply incised, bifid dorsal stylet, the lateral cuticularflange (the hyaline fringe of Cressey (1970)) on the caudal rami, and the small numberof unusually large endopodal denticulations are unique to this species. The three atypical cuticular flaps on the myxal area of the rnaxilliped are also found on K. dispat aspecies obviously unrelated.148The dorsal stylet of male K. elongata (Pillai, 1967), is very similar to that of K.Iongicauda.Kroyeriapapillipes Wilson, 1932(Figures 96-97)Material examined. One holotype female (USNM 56672) collected from the tiger shark,Galeocerdo cuvier (Peron & LeSueur, 1822); several females and a male (USNM153884-1 53899) collected by Dr. Roger Cressey, from the same host species from theWest coast of Florida.DescriptionFemale (Figure 96A)Overall length in dorsal view approximately 12.0 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Cephalothorax laterally extended relative to congeners. Dorsal stylets (Figures 96A, B) extending to midpoint of first free thoracic somite, stout, and curving slightly outward with blunt tips.Three free thoracic somites with non-overlapping terga. Genital complex cylindrical,constituting approximately 68 % of total body length. Posterolateral corners of latterbearing oviducal openings. Abdomen indistinctly one- or two-segmented. Caudal ramus(Figure 96C) lamelliform, longer than wide, devoid of typical medial fringe of setules,distally bearing six pinnate setae.First antenna (Figure 96D) indistinctly nine-segmented, armature (base to apex)as follows: 9, 1, 1, 5, 2, 3, 1, 1, 13 +1 aesthete. Second antenna (Figure 96E) chelateand prehensile, apparently four-segmented. Proximal two segments heavily scierotizedin such a way as to suggest relatively unrestricted movement capabilities. Third segment forming corpus of chela, extending into a rigid arm distally expanded into a smallreceptacle to accommodate tip of fourth segment. Latter forming heavily sclerotizedrobust claw, bearing three small setae proximally. Aperture of chela nearly circular dueto strongly curving claw. Mandible (Figure 96F) of two parts, dentiferous margin withten teeth somewhat uniform in size. First maxilla (Figure 96G) biramous; endopodlonger bearing two elongate pinnate (short pinnules) setae; exopod shorter bearing twoshort, naked setae. Second maxilla (Figure 96H) brachiform; lacertus (not illustrated)heavily sclerotized with elongate basal process arising from near base. Brachium withtwo large patches of prickles and a tuft of fine, long setae near base of claw; the latter149bearing paired lateral membranous lamellae with small prickles scattered upon convexsurface. Maxilliped (Figure 961) subchelate; corpus two-segmented, proximal segmentbearing two conical processes; myxal region of corpus with a tiny conical process; subchela not divided into shaft and claw, distally uncinate and bearing a single small, slender seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bears additional distomedial pinnate seta. Interpodal bars with poorly developed (absent?) interpodalstylets. Lateral fringe of setules on each endopodal segment, medial fringe of setuleson the first exopodal segment of each leg. Armature of rami as follows (Arabic numeralsdenote fully pinnate setae, Roman numerals denote conditions diverging from thatstate):Leg one Exopod I-i 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod I-i I-i 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 3Exopod of leg one (Figure 97A) bearing lateral membranes on segments one,two and three (additional pectinate strips on segments one, two and three). Segmentthree with four pinnate setae, plus two lateral naked setae. Endopod of leg one (Figure97A) with distolateral membranes on segments one and three; second segment bearsfive endopodal denticulations. Exopod of leg two (Figure 97B) similar to leg one,except second segment bears a lateral seta, third segment with four pinnate setae, plusone semipinnate seta with setules along the medial edge and a membrane along thelateral edge, and two naked lateralmost setae. Pectinate membranes paralleling thetypical membranes are present along the lateral margin of segments one, two, andthree. Endopod of leg two (Figure 97B) similar to leg one, except second segmentbears seven endopodal denticulations. Exopod of leg three (Figure 97C) as in leg two.Endopod of leg three (Figure 960) similar to endopod of leg two except seCond segment bears five to eight endopodal denticulations, and terminal segment bears four pinnate setae. Exopod of leg four (Figure 96D) as in leg three. Endopod of leg four (Figure96D) similar to leg three except terminal segment bears three pinnate seta, secondsegment similarly bears five to eight endopodal denticulations. Fifth leg not observed.Male: (Figure 97E)Total length approximately 5.4 mm. Appendages similar to female. Caudal rami150more elongate than that of female, and leg five and six represented by four and twosetae respectively.Comments: Kroyeria papillipes was originally described by Wilson (1932) fromthe tiger shark, Galeocerdo cuvier (Peron & LeSueur, 1822). The record of thisspecies parasitizing the smooth hammerhead, Sphyrna zygaena (Linnaeus, 1758) hasbeen found to be in error (see Cressey, 1970). All subsequent records have been fromgills of Galeocerdo cuvier.This species is the only member of the genus with allsix setae on the caudalrami elongate and pinnate, making it readily identifiable. Additionally, the endopodaldenticulations are restricted to the second segment ofeach endopod, similar to that inK. cresseyl.The short dorsal stylets, reduced or absent interpodal stylets, circular aperture ofthe chelate second antenna, and the indistinctly nine-segmented first antennae areattributes shared with K. dispar Wilson, 1935, which occurs on the same host •and geographic locality.Kroyeria procerobscena sp. nov.(Figures 98-99)Material examined. A few females (USNM 153860, 153858, 153857) collected by Dr.Roger Cressey, from the gills of the bull shark, Carcharhinus leucas (Valenciennes,1839) from near Nosy Be island, near Madagascar in the Mozambique Channel.Female holotype (USNM 266541) and 2 female paratypes (USNM266542) depositedat the United States National Museum of Natural History.Etymology: The specific name procerobscena derivedfrom the Latin procerus, meaning slender, long, stretched out, and from the Latin obscenus, meaning indecent, or private part, in reference to the extremely elongated genital complex of this species.DescriptionFemale (Figure 98A)Overall length in dorsal view approximately 17.7 mm.Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 98A-C) extending posteriorly to anterior margin of the second free thoracic151somite, stylets curving slightly inward. Dorsal stylets distally bifurcated with asharp tine(Figure 98B) or protuberance (Figure 98C) on the proximolateral edge approximately30% down the length of the stylet. Three free thoracic somites with overlapping terga.Genital complex cylindrical, constituting approximately 80 % of total body length.Posterolateral corners of latter bearing oviducal openings. Egg strands (Figure 98A)containing 89 and 97 eggs. Abdomen (Figures 98A, D) indistinctly two- or three-segmented. Caudal ramus (Figure 98E) lamelliform, longer than wide without medial fringeof setules, distally bearing two large pinnate setae (setules along inflated proximalhalves), two slender pinnate setae, one robust semipinnate seta, and one stoutplumose seta (a small setule arises from a raised crypt near the lateral border).First antenna (Figure 98F) indistinctly seven-segmented, armature (base toapex) as follows: 11, 5, 2, 3, 1, 1, 13 ÷1 aesthete. Second antenna (Figure 98G) chelateand prehensile, apparently four-segmented. Proximal two segments heavily scierotizedin such a way as to suggest relatively unrestricted movement capabilities. Third segment forming corpus of chela, extending into a rigid arm distally expanded into a receptacle to accommodate tip of fourth segment. Latter forming heavilysclerotized robustclaw, bearing three prominent setae (two slender and one truncate) proximally.Mandible (Figure 98H) of two parts, dentiferous margin with nine teeth (2 large, 2 small,2 large, 3 slightly smaller). First maxilla (Figure 98H) biramous; endopod longer bearingtwo apical elongate, pinnate setae; exopod shorter bearing two short, naked setae.Second maxilla (only distal portion illustrated) (Figure 981) brachiform; lacertus heavilyscierotized with basal process arising from near base. Brachium with two large patchesof prickles and a tuft of fine, long setae near base of claw; claw bearing paired lateralmembranous Iamellae with small prickles scattered upon convexsurface. Maxilliped(Figure 99A) subchelate; corpus two-segmented, proximal segment bearing twospinous processes; distal portion of corpus bearing sharp cuticular flange; subchela notdivided into shaft and claw, distally uncinate and bearing a singlesmall, slender seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and one or two distomedial membranes; firstbasipod bears additional distomedial pinnate seta; first coxopod bears two additional distolateral membranes. All four interpodal bars bearing interpodal stylets; interpodal stylets of leg oneacute but relatively small. Lateral fringe of setules on each endopodal segment, medial fringe of setules on the first exopodal segment of each leg. Armature of rami as follows (Arabic numerals denote fully pinnate setae, Roman numerals denote conditionsdiverging from that state):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-06152Leg two Exopod I-i I-i 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i I-i 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 99B) bearing distolateral membranes on segmentsone, two and three (membranes finely pectinate on segments two and three). Segmentthree with four pinnate setae, plus two lateral slender setae, the largest bears a membrane along its lateral edge and the smaller and lateralmost seta is naked. Endopod ofleg one (Figure 99B) with distolateral membrane on first segment; segment two with sixto seven (six shown) endopodal denticulations; segment three with eight to en (nineshown) endopodal denticulations. Exopod of leg two (Figure 99C) similar to leg one,except second segment bears additional lateral seta, and third segment with four pinnate setae, plus one semipinnate seta with setules along the medial edge and a membrane along the lateral edge, and two slender setae bearing membranes along their lateral edge. Pectinate membranes are present along the lateral margin of segments twoand three. Endopod of leg two (Figure 99C) similar to leg one, except seven endopodaldenticulations are present on the second segment and nine to twelve (nine shown)endopodal denticulations on the third segment. Exopod of leg three (Figure 99D) as inleg two, except the lateral membranes of the second and third segments are not pectinate. Endopod of leg three (Figure 99D) with seven to eight endopodal denticulationson segment two and eleven endopodal denticulations on segment three; segment threewith four pinnate setae. Exopod of leg four (Figure 99F) as in leg three, but pectinatemembranes on segments two and three and an additional pectinate strip parallels thetypical membrane on segment one. Endopod of leg four (Figure 99E) with six and nineendopodal denticulations on segments two and three respectively; segment three withtwo pinnate setae and one slender seta bilaterally bearing serrated membranes. Fifthleg not observed.Male: not acquiredComments: Kroyeria procerobscena is one of the giants in the genus. At nearly18 mm long its size is only rivalved by K. papillipes, K. dispai and K. gemursa, atapproximately 12.0, 13.1, and 14.4 mm respectively. Of course the mesoparasitic K.caseyl at nearly 60 mm in length remains in a class of its own.K. procerobscena also has an unusually long genital complex (hence its name),comprising 80% of the body length. The unusually long genital complex, the large size,the unique lateral tine on the proximal region of the bifid dorsal stylet, and the two elon153gate, proximally inflated, medially-pinched pinnate setae on the caudal rami distinguishthis from any other species in this genus.Kroyeria rhophemophaga sp. nov.(Figures 100-1 02)Material examined. Several females collected from the secondary lamellae of theCalifornia soupfin shark, Galeorhinus galeus (Linnaeus, 1758) from inshore waters offEl Segundo and Newport Beach, California, U.S.A. Female holotype (USNM 266539)and 5 female paratypes (USNM 266540) deposited at the United States NationalMuseum of Natural History.Etymology: The specific name is derived from the greek rhomphema, meaning soup,and the greek phagein, to eat, referring to this species’ predilection for feeding uponsoupfin sharks.DescriptionFemale (Figure 1 OOA)Overall length in dorsal view approximately 8.1 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures bOA-C) extending posteriorly to approximately 50 % down the length of thesecond free thoracic somite, stylets curving inward slightly with an acute terminus.Three free thoracic somites with non-overlapping terga. Genital complex cylindrical,constituting approximately 67 % of total body length. Posterolateral corners of latterbearing oviducal openings. Abdomen indistinctly three-segmented. Caudal ramus(Figure 100D) lamelliform, longer than wide bearing the typical medial fringe of setules,distally bearing four elongate pinnate setae and two stout, semipinnate setae. Eggstrands (Figure 100E) containing six eggs.First antenna (Figure 100E) indistinctly seven- or eight-segmented, rmature(base to apex) as follows: 11, 5, 1, 3, 1, 1 (missing in this specimen), 13+1 aesthete.Second antenna (Figure 100G) chelate and prehensile, apparently four-segmented.Proximal two segments heavily scierotized in such a way as to suggest the capablity ofrelatively unrestricted movement. Third segment forming corpus of chela, extendinginto a rigid arm distally expanded into a receptacle to accommodate tip of fourth segment. Latter forming heavily scierotized robust claw, bearing one elongate, slender seta154arising from concave margin in aperture of chela, and one proximal slender seta.Mandible (Figure 100H) of two parts, dentiferous margin with nine (2 large, 2 small, 2large, and 3 small descending in size) teeth. First maxilla (Figure 1001) biramous;endopod longer bearing two apical elongate, pinnate setae; exopod shorter bearing twoshort, naked setae. Second maxilla (Figure 100J) brachiform; lacertus heavily scierotized with large basal process arising from near base. Brachium with two large patchesof prickles and a tuft of fine, long setae near base of claw. Claw bearing paired lateralmembranous lamellae, with membrane bearing prickles along the convex surface.Maxilliped (Figure lOlA) subchelate; corpus two-segmented; subchela not divided intoshaft and claw, distally uncinate and bearing a single small slender seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bearsadditional distomedia! pinnate seta. All four interpodal bars bearing elongate interpodal stylets; interpodal stylets of leg one smaller than others. Lateral fringe of setules on endopodal segments one and two, and on segment three on leg four. Medial fringe of setules on theproximal segment of each exopod. Armature of rami as follows (Arabic numeralsdenote fully pinnate setae, Roman numerals denote conditions diverging from thatstate):Leg one Exopod [-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod 1-1 0-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i (-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 1O1B) bearing pectinate lateral membranes on segments one, two and three. Segment three with four pinnate setae,plus two slendersetae; longer of the two with membrane along lateral edge. Endopod ofleg one (Figure1018) with distolateral membrane on first segment; segment two with five to sixendopodal denticulations; segment three with lateral membrane, and sixpinnate setae.Exopod of leg two (Figure 1O1C) similar to leg one, except three distolateral slendersetae (two bearing lateral membranes and lateralmost seta smallest and naked)arepresent. Endopod of leg two (Figure 1O1C) similar to leg one, with five to sevenendopodal denticulations present on the second segment, a distolateral membraneand six pinnate setae are present on the third segment. Exopod of leg three (Figure101 D) similar to leg two except second segment bears a small lateral slender seta, andthe largest slender on the terminal segment seta is semipinnate with a membrane alongthe lateral edge. Endopod of leg three (Figure 101 D) with three to eight endopodal den-155ticulations on segment two (eight shown); segment three bears four pinnate setae andone lateral membrane. Exopod of leg four (Figure 101 E) similar to exopod of leg three.Endopod of leg four (Figure 101 E) with nine endopodal denticulations on segment two;one lateral stout seta bilaterally bearing finely serrated membranes, and two pinnatesetae tip segment three. Fifth leg not found.Male: (Figures 102A, B)Overall length in dorsal view approximately 2.1 mm. Cephalothoracicappendages and swimming legs similar to those of female. Genital complex bearingfifth and sixth legs represented by four and two pinnate setae respectively. Dorsal stylet(Figure 102A) shorter and more stout than that of female. Caudal ramus (Figure 102C)more elongate than that of female, bearing six distal setae (two short and apicallyplumose; two long and pinnate, and two small slender pinnate). Second segment ofendopods (Figure 102D) bears three large endopodal denticulations and a row of longsetules fringing the lateral margin.Comments: Kroyeria rhophemophaga resembles K. branchiocetes, K. lineata,K. cresseyl, and K. triakos in that the claw of the second antennae bears two ratherthan three elongate slender setae. K. rhophemophaga differs most notably form K.branchiocetes and K. lineata by lacking the large membranous expansions found distally on the claw and corpus of the second antennae. K. rhophemophaga is easily distinguished from K. triakos by possessing only four pinnate setae plus two lateral slendersetae on the terminal segment of exopod three; K. triakos bears five pinnate setae plusone naked slender seta. Finally, the cephalothorax of K. cresseyl is orbicular ratherthan subquadrangular as in K. rhophemophaga.I was also able to examine four specimens of Kroyeria from Galeorhinus galeusfrom Kaikoura, New Zealand, collected by Dr. Pilgrim. These specimens resembled K.rhophemophaga from southern California specimens that were only about 4.4 mm inlength. This is approximately 54% the length of the specimens described herein. Untilmore data are acquired, populations of Kroyeria from the California and New Zealandsoupfin sharks, Galeorhinus galeus, will be considered conspecific.Interestingly, K. lineata from the soupfin or tope shark, Galeorhinus galeus fromthe eastern Atlantic, is markedly different from the K. rhophemophaga from the easternNorth Pacific (California) and New Zealand. Many of species-specific elasmobranchinfecting copepods,have a geographic range concomitant with that of their hosts.Perhaps the synonymy of the six species of Galeorhinus into G. galeus by Compagno(1984b) is mistaken. The different parasite species and striking difference in the size156between the aforementioned Pacific samples suggest distinct stocks of these soupfins.Kroyeria spatulata Pearse, 1948(Figuresi 03-104)Material examined. Several females (USNM 154009) collected by Dr. Cressey from thegills of the bull shark, Carcharhinus leucas (Valenciennes, 1839) from Sarasota, Florida;and a few females (USNM 271 635) collected by Dr. Roger Cressey, from the gills ofthe lemon shark, Negaprion brevirostris (Poey, 1868) from Sarasota, Florida.DescriptionFemale (Figure 103A)Overall length in dorsal view approximately 5.4 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 103A and 103B) extending near posterior margin of second free thoracicsomite, stylets slightly curving inward with a bifid terminus. Three free thoracic somiteswith slightly overlapping terga. Genital complex cylindrical, constituting approximately57 % of total body length. Posterolateral corners of latter bearing oviducal openings.Abdomen indistinctly three-segmented. Caudal ramus (Figure 103C) lamelliform, longerthan wide with fringe of setules along medial margin, bearing five pinnate setae (fourelongate and one stout) and one large, stout, semipinnate seta.First antenna (Figure 103D) indistinctly seven- to eight-segmented, armature(base to apex) as follows: 11, 5, 2, 3, 1, 1, 13 +1 aesthete. Second antenna (Figure103E) chelate and prehensile, apparently four-segmented. Proximal two segmentsheavily sclerotized in such a way as to suggest relatively unrestricted movement capabilities. Third segment forming corpus of chela, extending into a rigid arm, distallyexpanded into a receptacle to accommodate tip of fourth segment. Latter forming heavily sclerotized robust claw, bearing three prominent slender setae. Mandible (Figure103F) of two parts, dentiferous margin with nine teeth (1 apical, 2 large, 2 small, 2large, and 3 small decreasing in size). First maxilla (Figure 103G) biramous; endopodlonger bearing two apical elongate, unilaterally denticulated setae; exopod shorterbearing two short, naked setae. Second maxilla (Figure 103H) brachiform; lacertusheavily sclerotized with large basal process arising from near base. Brachium with twolarge patches of prickles and a tuft of fine, long setae near base of claw; the latter bearing paired lateral membranous lamellae with small prickles scattered upon convex sur157face. Maxilliped (Figure 104A) subchelate; corpus two-segmented, proximal segmentwith three small spinous processes, distal region of distal segment of corpus bearing atransverse cuticular flange; subchela not divided into shaft and claw, distally uncinateand bearing a single small slender seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bears additional distomedial pinnate seta, coxopod of leg one bears additional distolateral membrane.Interpodal bars with interpodal stylets (leg one interpodal stylet very small and blunt).Lateral fringe of setules present on segments one and two of all endopods, and on segment three of the endopod of leg four; medial fringe of setules on the first exopodalsegment of each leg. Armature of rami as follows (Arabic numerals denote fully pinnatesetae, Roman numerals denote conditions diverging from that state):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod I-i 1-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 104B) bearing pectinate lateral membranes on segments one, two and three, typical membrane paralleling pectinate membrane on firstsegment. Segment three with four pinnate setae, plus two lateral slender setae (lateral-most seta naked, the adjacent seta bears a membrane along lateral edge). Endopod ofleg one (Figure 104B) with distolateral membrane on first segment, seven to nineendopodal denticulations on the second segment, and ten to eleven endopodal denticulations on the terminal segment. Exopod of leg two (Figure 104C) similar to leg one,except second segment bears lateral seta , and third segment bears four pinnate setae,plus one semipinnate seta with setules along the medial edge and a membrane alongthe lateral edge, and laterally, two slender seta, the larger bearing a membrane alongthe lateral edge. Endopod of leg two (Figure 104C) similar to endopod of leg one,except second segment bears nine to eleven endopodal denticulations, segment threebears thirteen endopodal denticulations. Exopod of leg three (Figure 104D) as in legtwo, except pectinate membrane paralleling typical membrane is present. Endopod ofleg three (Figure 104D) similar to leg two but segment three bears only four pinnatesetae, segment two bears nine to ten endopodal denticulations, and segment threebears thirteen to fifteen endopodal denticulations. Exopod of leg four (Figure 104F)with pectinate membranes arising medial to the distolateral setae of segments one andtwo, and arising medial to the second most lateral seta, and all sinuously wrapping158down along lateral margins of segments one, two, and three (obviously the diagnosticsaddlelike sclerotizations noted by Cressey (1 970)). Membranes present orr all threesegments. ndopod of leg four (Figure 104E) similar to leg three except second segment medially bears pinnate seta, and terminal segment bears one stout seta bilaterallybearing finely serrated membranes plus two pinnate setae. Second and third segmentsbear ten and eleven endopodal denticulations respectively. Leg five not observed.Male: not acquiredComments: Kroyeria spatulata was originally described by Pearse (1948) fromthe sharpnosed shark, Scoiodon terraenovae (Richardson, 1836) (=Rhizoprionodonterraenovae (Richardson, 1836)) from off Beaufort, North Carolina, U.S.A. Since then ithas been reported from the sandtiger shark, Carcharias littoralis (=Eugomophodes taurus (Rafinesque, 1810)), and from the Bahamas (Pearse, 1951), from the blacktipshark, Carcharhinus limbatus (Valenciennes, 1 839) from the Gulf of Mexico (Pearse,1952b). Cressey (1967) reported it from the spinner shark, Carcharhinus maculipinnis(Poey, 1865) (=Carcharhinus brevipinna (Muller and Henle, 1839)), the spot-tail shark,Carcharhinus sorrah (Valenciennes, 1839), and from the milk shark, Rhizoprionodonacutus (Ruppel, 1837) all from the Indian Ocean. Following these reports, K. spatulatawas reported by Cressey (1970) from the lemon shark, Negaprion brevirostris (Poey,1868), and the bull shark, Carcharhinus leucas (Valenciennes, 1839) from off the Westcoast of Florida.Having been fortunate enough to examine many of these specimens collected bythe International Indian Ocean Expedition I found the record of K. spatulata on C. brevipinna to be in error. The correct identification of the parasite is K. longicauda.Furthermore, the record of K. spatulata on C. sorrah should be changed to K. elongata(assuming host identification is accurate).This species is problematic in that the original description by Pearse (1948) wasincomplete, and inconsistent with the illustrations. First, the corpus of the secondantenna is not uniquely spatulate as described in the text. Second, Pearse states thatthere are no papillae (the endopodal denticulations herein) on the middle endopod segment of all legs, yet the illustrations of the apparently broken first leg and the fourth leg(legs two and three were not illustrated) distinctly show these to be present. Addingmisery, the hideously distorted type specimen is distorted and compressed, and was ofno value in sorting these inconsistencies out. The only illustration of this species sincethe original one by Pearse was a single illustration of the fourth leg by Cressey (1970)detailing the diagnostic “saddlelike sclerotizations on the distolateral corners on seg159ments two and three of the fourth leg exopod”, which corresponds to the sinuous pectinate membranes described herein. Pillai (1985) sync nimized K. spatulata with K. elongata, but this is clearly in error as outlined above in the comments section under K.elongata.This species is easily distinguished from all other congeners by the unique sinuous, pectinate membranes arising medial to the spiniform setae and wrapping down thelateral margins of segments two and three on the exopod of leg four.Kroyeria sphyrnae Rangnekar, 1957(Figures 105-1 06)Syn: Kroyeria praelongacicula Lewis, 1966, syn. nov.Material examined. Several paratype females of K. praelongacicula (USNM 110800)collected By Dr. Alan Lewis, University of British Columbia, from the gills of the scalloped hammerhead, Sphyrna lewini (Griffith and Smith, 1834) from the HawaiianIslands near Kaneohe Bay; numerous females from the same host species from PuntaArena de Ia Ventana, in the southern Sea of Cortez (Gulf of California), Mexico; andnumerous females from the smooth hammerhead, Sphyrna zygaena (Linnaeus, 1758)from Punta Arena de Ia Ventana, Mexico, and from near the Channel Islands, in thesouthern California bight.DescriptionFemale (Figure 105-106)Overall length in dorsal view approximately 8.7 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 105A-C) extending beyond fourth free thoracic somite, stylets extremely elongate, lissome, with an acute terminus. Three free thoracic somites with non-overlappingterga. Genital complex cylindrical, constituting approximately 60 °k of total body length.Posterolateral corners of latter bearing oviducal openings. Abdomen indistinctly threesegmented. Caudal ramus (Figure 105D) lamelliform, longer than wide with medialfringe of setules, bearing four pinnate setae distally, and distolaterally bearing two stoutsemipinnate setae.First antenna (Figure 105E and (terminal segment detail) 104F) indistinctlyseven- to eight-segmented, armature (base to apex) as follows: 11,3, 1, 3, 1, 1, 13+1aesthete. Second antenna (Figure 1 05G) chelate and prehensile, apparently .four-seg160mented. Proximal two segments heavily sclerotized in such a way as to suggest relatively unrestricted movement capabilities. Third segment forming corpus of chela,extending into a rigid arm distally expanded into a small receptacle to accommodate tipof fourth segment. Latter forming heavily scierotized robust claw, bearing three prominent setae proximally. Aperture of chela small due to stout claw and extension ofcorpus. Mandible (Figure 105H) of two parts, dentiferous margin with seven teeth (1large, 2 small, 2 large, and 2 small decreasing in size). First maxilla (Figure 1051) biramous; endopod longer bearing two apical elongate, setae (one naked and one pinnate); exopod shorter bearing two short, naked setae. Second maxilla (Figure 106A)brachiform; lacertus heavily sclerotized with elongate basal process arising from nearbase. Brachium with two large patches of prickles and a tuft of fine, long setae nearbase of claw; the latter (see detail) bearing paired lateral membranous lamellae withsmall prickles scattered upon convex surface. Maxilliped (Figure 106B) subchelate;corpus two-segmented, proximal segment bearing a single conical process; subchelanot divided into shaft and claw, distally uncinate and bearing a single small slenderseta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bears additional distomedial pinnate seta. Interpodal bars with interpodal stylets (leg one interpodal styletvery small and blunt), remaining three legs all possess interpodal stylets relativelysmaller than the majority of the genus. Lateral fringe of setules present on the first andsecond segments of endopods one through four, and on the third segment of leg four;medial fringe of setules on the first exopodal segment of each leg. Armature of rami asfollows (Arabic numerals denote fully pinnate setae, Roman numerals denote conditions diverging from that state):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod I-i 1-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 111,4 Endopod 0-1 0-0 4Leg four Exopod I-i 1-1 111,4 Endopod 0-1 0-1 1,2Exopod of leg one (Figure 106C) bearing lateral membranes on segments one,two and three. Segment three with four pinnate setae, plus two lateral slender setae(lateralmost seta small and naked, the adjacent seta bears a membrane along lateraledge). Endopod of leg one (Figure 1060) with distolateral membrane on first segment,six to nine endopodal denticulations on the second segment, and eight to nine endopodal denticulations on the terminal segment. Exopod of leg two (Figure 106D) similar to161leg one, except second segment bears lateral seta , and third segment bears four pinnate setae, plus one semipinnate seta with setules along the medial edge and a finelyserrated membrane along the lateral edge, one slender seta bearing a lateral membrane and a small naked lateralmost seta. Endopod of leg two (Figure 1 06D) similar toendopod of leg one, except second segment bears seven to eleven endopodal denticulations, and segment three bears eight to ten endopodal denticulations. Exopod of legthree (Figure 106E) as in leg two. Endopod of leg three (Figure 106E) similar to leg twobut segment three bears only four pinnate setae, segment two bears nine to tenendopodal denticulations, and segment three bears nine to eleven endopodal denticulations. Exopod of leg four (Figure 106F) as in leg three. Endopod of leg four (Figure106F) similar to leg three except second segment medially bears pinnate seta, and terminal segment bears one stout seta bilaterally bearing serrated membrane plus twopinnate setae. Second and third segments bear eight to nine and eight to elevenendopodal denticulations respectively.Male: not acquired.Comments: Kroyeria sphyrnae was originally described by Rangnekar (1957)from an unknown species of hammerhead, Sphyrna sp. in India, presumably in theBombay region. The next record of K. sphyrnae came from the gills of the smoothhammerhead, Sphyrna zygaena (Linnaeus, 1758) from Trivandrum, India (Pillai, 1967).Kabata (1970) presented a tentative find of K. sphyrnae from a single non-ovigerousspecimen collected from the brownbanded bamboo shark, Chiloscyllium punctatumMuller and Henle, 1838 (Orectolobiformes: Hemiscylliidae), from Moreton Bay,Queensland, Australia. Unfortunately, no illustrations or dimensions accompanied thatreport, and specific identification of the specimen remains open to question. Cressey(1970) claimed to have discovered it from the blacknose shark, Carcharhinus acronotus(Poey, 1860) from the West coast of Florida. Again, no illustrations accompanied thatreport, but Cressey did include total length of the specimens, which were reported to bevery small (2.2 mm). PilIai (1985) superficially describes the species and summarizesreported host associations of this parasite.Lewis (1 966a) described a new species, Kroyeria praelongacicula, from the scalloped hammerhead, Sphyrna lewini (Griffith and Smith, 1834) from Kaneohe Bay,Oahu, Hawaii. These specimens appear to be conspecific with K. sphyrnae. Thestrange irregular bifid tip of the dorsal stylet illustrated in Lewis’ description of K. praelongacicula, was not observed in the paratypes I examined. Based on the .paratypespecimens examined and specimens collected from the same host species in the162southern Sea of Cortez, and southern California Bight in the eastern North Pacific, andthe descriptions offered by Rangnekar (1957) and Pillai (1967, 1985), K praelongacicuIa is considered a synonym of K. sphyrnae.Cressey’s (1 970) record of K. sphyrnae is suspect. Cressey reports the length ofK. sphyrnae as only 2.2 mm, which is quite small considering the original description byRangnekar measures this species at 4.7 mm. Lewis (1966a) reports a range of 6.58-8.12 mm, and a total length of approximately 8.7 mm was found herein. It is unlikelyCressey’s (1970) record represents the same species. Cressey notes that the smallsize combined with the last two segments of the endopod of the fourth leg bearing onlytwo or three lateral spinules (the endopodal denticulations herein) make specific identification easy. Neither of these characteristics apply to K. sphyrnae. What speciesCressey’s (1970) record represents is uncertain.K. sphyrnae is a parasite of smooth and scalloped hammerheads, Sphyrnazygaena and Sphyrna lewini, respectively. My unpublished field observations from bothsouthern California and the southern Sea of Cortez suggest S. zygaena is the preferredhost as the parasite load is higher on this host.The long, acute, lissome dorsal stylets, the formula of the seven-toothedmandible, and the relatively short interpodal stylets which barely reach the distal marginof the basipods of legs two, three, and four readily distinguish this species.Kroyeria triakos Fukui, 1965 nom. emend.(Figures 107-108)Syn: Kroyeria elongatus Fukui, 1965Kroyeria triakisae Fukui, 1965nec Kroyeria elongata Pillai, 1967Material examined. Two females collected from the secondary lamellae of the bandedhoundshark, Triakis scyllium Muller and Henle, 1839 (USNM 22607) from inshorewaters off Awa, Japan.DescriptionFemale (Figure 1 07A)Overall length in dorsal view approximately 4.6 mm. Cephalothoracic suturesarising anterolaterally and uniting posteromedially. Eyes not evident. Dorsal stylets(Figures 1 07A, B) extending to the posterior margin of the second free thoracic somite,163stylets curving inward slightly with a narrow distolateral flange. Three free thoracicsomites with slightly overlapping terga. Genital complex cylindrical, constituting approximately 66 % of total body length. Posterolateral corners of latter bearing oviducal openings. Abdomen indistinctly three-segmented. Caudal ramus (Figure 107C) lamelliform,longer than wide bearing the typical medial fringe of setules, distally bearing two elongate pinnate setae, two shorter pinnate setae and two stout semipinnate setae.First antenna (Figure 107D) indistinctly seven- or eight-segmented, armature(base to apex) as follows: 9, 1, 5, 1, 3, 1, 1, 13 +1 aesthete. Second antenna (Figure107E) chelate and prehensile, apparently four-segmented. Proximal two segmentsheavily scierotized in such a way as to suggest the capablity of relatively unrestrictedmovement. Third segment forming corpus of chela, extending into a rigid arm distallyexpanded into a receptacle to accommodate tip of fourth segment. Latter forming heavily sclerotized robust claw, bearing one elongate slender seta along concave margin inaperture of chela, and proximally, one elongate seta. Mandible (Figure 107F) of twoparts, dentiferous margin with nine (1 apical, 2 large, 2 small, 2 large, and 2 small) teeth.First maxilla (Figure 1 07G) biramous; endopod longer bearing two apical elongate, pinnate setae; exopod shorter bearing two short, naked setae. Second maxilla (Figure107H) brachiform; lacertus heavily sclerotized with long basal process arising from nearbase. Brachium with two large patches of prickles and a tuft of fine, long setae nearbase of claw. Claw bearing membranous lamellae, specifics difficult to ascertain due tosmall size. Maxilliped (Figure 1 071) subchelate; corpus two-segmented, proximal segment bearing one conical process, distolateral region of main corpus bears transversecuticular flange; subchela not divided into shaft and claw, distally uncinate and bearinga single small, slender seta.All four legs biramous and trimerite. Sympods two-segmented. All basipods withlateral pinnate seta and two distomedial membranes; first basipod bears additional distomedial pinnate seta; first coxopod bears two additional membranes. All four interpodalbars bearing elongate interpodal stylets; those of leg one smaller than others. Lateralfringe of setules on endopodal segments two and three, medial fringe of setules on thefirst segment of each exopod. Armature of rami as follows (Arabic numerals denote fullypinnate setae, Roman numerals denote conditions diverging from that state):Leg one Exopod 1-1 0-1 11,4 Endopod 0-1 0-0 6Leg two Exopod 1-1 0-1 111,4 Endopod 0-1 0-0 6Leg three Exopod I-i 1-1 1,5 Endopod 0-1 0-0 4Leg four Exopod 0-1 0-1 111,4 Endopod 0-1 0-1 1,2164Exopod of leg one (Figure 108A) bearing lateral membranes on segments one,two and three. Segment three with four pinnate setae, plus two slender naked setae.Endopod of leg one (Figure 108A) with distolateral membrane on first segment; segment two with seven endopodal denticulations; segment three bearing six pinnatesetae, and apparently devoid of typical distolateral membrane. Exopod of leg two(Figure 108B) similar to leg one, except third lateralmost seta is semipinnate withsetules along the medial edge, the two lateralmost setae slender and apparently naked.Enclopod of leg two (Figure 1080) similar to leg one, with six to eight endopodal denticulations (eight shown) present on the second segment, and a lateral membrane and sixpinnate setae on the third segment. Exopod of leg three (Figure 108D) similar to legtwo except second segment bears a small lateral seta, and the terminal segment bearson’y one naked, lateral setae and five pinnate setae. Endopod of leg three (Figure108E) with seven to ten endopodal denticulations on segment two (seven shown); segment three bears four pinnate setae and one distolateral membrane. Exopod of leg four(Figure 108F) without typical lateral setae on segments one and two, terminal segmentwith four pinnate setae, one semipinnate seta, one slender seta bearing a serratedmembrane, and the lateralmost slender seta naked. Endopod of leg four (Figure 108F)with indistinct membranous, endopodal denticulations forming the membrane, or transparent supports for the membrane (illustrated as a typical membrane) on segment two(this could be interpreted as devoid of endopodal denticulations or antithetically, possessing very many fused, membranous endopodal denticulations); one lateral stoutseta bilaterally bearing serrated membranes, and two pinnate setae tip segment three.Fifth leg not found.Comments: As noted above, Kroyeria triakos, K. branchiocetes, K. lineata, K.rhophemophaga, and K. cresseyi differ from their congeners in that the claw of the second antenna is armed with only two slender setae. Differences between species in thiscomplex have already been outlined in the comments section for K. cresseyl.K. triakos was originally described by Fukul (1 965) from gills of a young, bandedhoundshark, Triakis scyllium Muller and Henle, 1839, from Kurihama, in the Kanagawaprefecture collected in 1955. Although his description is incomplete, the unique shapeof the cephalothorax (almost arrowhead shaped; “the cobra with protrusions in the posterior corners” of Fukui (1965)), the similar dimensions, and the fact that both collections come from the same host species in Japanese waters leave no doubt that specimens examined here are conspecific with Fukui’s material. Fukui (1965) assigned thenew Japanese name Dochi-zame-hoso-yadori Ken-mizinko, (meaning, the elongatedKroyeria from Triakis) to this parasite. Strangely, he also assigns two binomens to this165copepod, keeping the Japanese name the same in both instances. Kroyeria elongatusis the first name to show up in the publication in the figure caption preceeding the actualdescription. The name Kroyeria triakisae occurs in the narrative, describing the species.Fukui’s K. elongatus should be K. elongata (Kroyer/a is feminine), making it ahomonym of Pillai’s (1967) K. elongata. This would force one to correct the gender ofFukul’s species and rename Pillai’s. However, for the sake of nomenclatural stabilityand to minimize further taxonomic confusion in the genus, this species will retain thename K. triakisae. Since the name is a Greek noun, its genitive singular is triakos. Ipropose, therefore to amend Fukui’s K. triakisae to K. triakos. This leaves Pillai’s (1967)K. elongata, unchanged.K. triakos is easily recognized by being the only species in the genus that hasfive elongate, pinnate setae on the third segment of the third leg. It is also the onlyspecies lacking the typical lateral setae on segments one and two of the fourth exopod.The latter feature is suggested here only tentatively, for two reasons. Firstly, it is otherwise unknown in Kroyeriidae; secondly, material available for examination was not adequate to determine it beyond a reasonable doubt.REMAINING UNOBTAINABLE NOMINAL SPECIESKroyeria consists of 18 nominal species. Three of them, (K. acanthiasvulgarisHesse, 1879, K. galeivulgaris Hesse, 1884, and K. scyliicaniculae Hesse, 1879) havenot been sufficiently well described to be recognized and must be considered speciesinquirenda. K.trecai Delamare Deboutteville and Nunes-Ruivo, 1953 was neverdescribed and remains a nomen nudum. K. aculeata (Gerstaecker, 1854) and K. sublineata Yamaguti and Yamasu, 1959 are considered junior synonyms of K. lineata vanBeneden, 1853. K. grad/is Wilson, 1 932 similarly is considered a junior synonym of K.carchariaeglauci Hesse, 1879, and K. praelongacicula Lewis 1966 is a synonym of K.sphyrnae Rangnekar, 1957. This revision resurrects K. elongata Pillai, 1967.This section is a brief (alphabetical) account of the females of the uncertainspecies above and the remaining species that were not available for this revision ofKroyeria.Kroyeria acanthiasvulgaris Hesse, 1879 was described from the spiny dogfish,Acanthias vulgar/s Risso, 1826 (=Squalus acanthias Smith and Radcliffe, 1912), fromoff Brest, France. I have examined literally hundreds of this host species, and theyonly harbored Eudactylina acanthil A. Scott, 1901. Since many triakids or smooth-hounds are morphologically similar to this reported squaloid host, host misidentification166is a likely explanation for this unlikely host-parasite association.Kroyeria echinata Rangnekar, 1956 was reported from the body surface of thesmooth hammerhead, Sphyrna zygaena (Linnaeus, 1758) from the Indian Ocean nearBombay, India. The description is too superficial for detailed comparisons. AlthoughPilIai’s (1985) redescription is helpful, some interpretations (setation on distal elementsof the caudal rami and legs, and the number of slender setae on the claw of the secondantennae) are suspect. Pillai (1985) reports this parasite from the smooth hammerheadfrom Kerala, India. The short stout dorsal stylets are reminiscent of those found in K.dispar and K. papillipes, but can be distinguished from these two by their small size(approximately 3.2-4.1 mm, compared to the 13.1 and 12.0 mm of K. dispar and K.papillipes respectively). The endopods of K. dispar are devoid of endopodal denticulations, and they are restricted to the second segment only of all four legs in K. papillipesand K. echinata. The orbicular cephalothorax of K. papillipes is quite distinct from thatof K. echinatus as is the armature of the setae on the caudal rami and the legs.Kroyeria gale/vulgar/s Hesse, 1884 was reported from the Tope shark, Galeusvulgar/s Fleming, 1828 (=Galeorhinus galeus (Linnaeus, 1758)). This may represent K.lineata, considering the host and geographic locality (Brest, France).Kroyer/a minuta Pillai, 1968 was described from gill filaments of the milk shark,Scoliodon sorrokowah (Bleeker, 1853), (=Rhizoprionodon acutus (Ruppel, 1837)), fromKerala, India. This is a small species, only about 3.0 mm in length. The long bifid dorsalstylets reaching the posterior margin of the fourth free thoracic somite, coupled with thesupposed and questionable serrated medial margins (I suspect these serrations are thetypical endopodal denticulations characteristically found throughout the genus), and theatypical patch of spinules on the lateral margin of the coxopod of leg two, plus the existence of six fully pinnate setae on the terminal segment of the exopod of leg two, readily distinguish this species.Kroyeria scyllicaniculae Hesse, 1879 was originally reported from the small-spotted catshark, Scyllium canicula (=Scyliorh/nus canicula (Linnaeus, 1758)), fromBrest, France. Unfortunately, K. scyllicaniculae a species /nquirenda comes from theScyliorhinidae, a host family with very little parasitic copepod information.Kroyeria trecai Delamare Deboutteville and Nunes-Ruivo, 1953 was reportedfrom the smooth hammerhead, Sphyrna zygaena (Linnaeus, 1758) and from the scalloped hammerhead, Sphyrna diplana Springer, 1941 (=Sphyrna lewini (Griffith andSmith, 1834)) from off the coast of Senegal. Although no description was ever published, they mention the species is characterized by its styliform processes projectingpast the level of the genital segment, by having a one-segmented abdomen and by itscaudal rami ending in 4 subequal setae, the 2 longer being ciliated. The long dorsal167styets coupled to the fact that this species is found on the same sphyrnid hosts asKroyeria sphyrnae suggests that these two species may be synonyms.PHYLOGENETIC ANALYSISCLADOGRAM CONSTRUCTIONA phylogenetic analysis was conducted of the 1 6 species of Kroyeria revisedherein. The outgroup was composed of the presumed sister taxon, Kroeyerina, andProkroyeria (presumed sister to Kroyeria and Kroeyerina) (Figure 109; see Deets,1987 for details). A total of 44 characters (see Appendix C for data matrix and definition of characters) were analyzed using an exact search Branch and Bound algorithmof PAUP. The most parsimonious tree for Kroyeria (Figure 110) had a tree length of165, a consistency index of 0.75 (maximum value = 1.00), a retention index of 0.75(maximum value = 1.00), and an F- ratio of 0.0589 (maximum value=0). Change and/orsynapomorphy lists may be obtained from the author.The first two branches arising from the base of the cladogram are representedby K. dispar and K. papillipes respectively, both parasites of the tiger shark, Galeocerdocuvier. The next dade is composed of parasites specific to the Triakidae: the majordichotomy in this dade separates K. lineata (parasites of Galeorhinus galeus andMustelus spp.) and K. rhophemophaga (parasite of Californian Galeorhinus galeus)from K. triakos and K. cresseyl, parasites of the Japanese and Californian ‘eopardsharks, Triakis scyllium and Triakis semifasciata, respectively. The next dade up thecladogram holds two species, K. sphyrnae and K. gemursa, parasites of the hammerhead genus Sphyrna. A paraphyletic triad follows consisting of the bizarre, mesoparasitic K. caseyl, parasitic on the night shark, Carcharhinus signatus, K. spatulata, foundon various species of Carcharhinus, Negaprion, and Rhizoprionodon, and K. procerobscenum a parasite of the bull shark, C. leucas. The final major bifurcation leads to onedade composed of K. branchiocetes, K. longicauda, and K. elongata, parasites of various species of Carcharhinus, and a dade composed of K. decepta, specific to thedusky shark, C. obscurus, and K. carchariaeglauci parasitic on the epipelagic silkyshark, C. falciformis, the pelagic whitetip, C. longimanus, and the blue shark Prionaceglauca.168PARASITE-DERIVED HOST CLADOG RAMSThe Kroyeria cladogram was recoded by additive binary coding and a host byparasite data matrix was created (Table Ill).The phylogenetic analysis conducted from the recoded species of Kroyeria byhost matrix (Table 3) resulted in a single most-parsimonious tree (Figure 111). TheBranch and Bound generated tree had a tree length of 30, and a consistency indexwith a maximum value of 1.00.The parasite-derived host cladogram shows some unexpected patterns. Thefirst two branches at the base of the tree posit a paraphyletic relationship for the presumably monophyletic tiger shark, Galeocerdo cuvier. This artifact is due to this hostpossessing two different species of Kroyeria. Using parasite species as characters inthis case would be analogous to coding an organism for phylogenetic analysisthat possessed two different character states of a given character simultaneously. InclusiveOR’ing, a technique previously used to code for the occurrence of more than one parasite taxon per host could have been used to force Galeocerdo into monophyly, howeverthis technique, if not restricted to treatment of parasite sister taxa, creates a chimeraout of unmodified data, resulting in the distortion of phylogenetic information (seeO’Grady and Deets, 1987 for details).The next dade contains members of the Triakidae. This dade consists of onegroup housing the leopard sharks Triakis semifasciata from the California coast ,and Tscyllium from Japanese waters. The remaining dade contains the soupfin sharkGaleorhinus galeus functioning as the sister taxon to a dade composed of the G.galeus and various species of Mustelus from the western North Atlantic andMediterranean. The monophyly of G. galeus with the many Mustelus species is due tothis host complex sharing the common parasite, K. lineata. The other branch leading toG. galeus stands alone as this soupfin shark from California waters possesses its owncopepod K. rhophemophaga.The next dade contains all hammerheads of the genus Sphyrna. Thegreat hammerhead, Sphyrna mokarran is sister taxon to the dade consisting of scalloped and smooth hammerheads, Sphyrna lewini and S. zygaena, respectively. Thenight shark, Carcharhinus signatus is the first Carcharhinus to appear on the cladogram followed by a dade consisting of the bull shark, C. leucas and the lemon shark,Negaprion brevirostris both possessing K. spatulata. C. leucas is unresolved with twoclades, one with five the other with four taxa. The five taxon dade consists of the Greyreef shark, C. amblyrhynchos which is the sister taxon to a dade composed of two169smaller groups. The first group contains the spinner shark, C. brevipinna and the black-tip, C. limbatus. The remaining group is composed of the spot-tail shark, C. sorrah andthe milk shark Rhizoprionodon acutus. The four taxon dade on consists of the duskyshark, C. obscurus, the sister taxon to an unresolved trichotomy of pelagic tropical totemperate carcharhinids, the silky shark, C. falciformis, the pelagic whitetip, C. longimanus, and the blue shark, Prionace glauca.COMBINING PARASITE CLADOG RAMSIf parasites can be used as characters, and if they possess symplesiomorphic,synapomorphic, or autapomorphic relationships with their hosts as do typical charactersin phylogenetic analyses, then we should gain resolution regarding host relationshipswith addition of parasite phylogenies (assuming an hypothesis of strict co-speciation).Additionally, Brooks and McClennan (1991, 1993) claim the methods appliedin singledade analysis can be used for multiple clades simultaneously.Kroeyerina Wilson, 1932 (Figure 112) is a genus of copepods dwelling in olfactory Iamellae of elasmobranchs. Deets (1987) generated a parasite cladogram and aparasite-derived host cladogram of the genus. During the course of this studyKroeyerina cortezensis Deets, 1987, originally reported from the silky shark,Carcharhinus falciformis, was discovered from olfactory lamellae of the pelagic whitetip,Carcharhinus longimanus, captured in a tuna seine off the Revillagegedos Islands,Mexico in September of 1988. Hence the parasite-derived host dladogram forKroeyerina is slightly different from the original with the incorporation of the pelagicwhitetip (Figure 113).The Kroeyerina cladogram from Deets (1987) was converted into a binary code(Table Ill), and then added to the binary code for Kroyeria (Table II) resulting in the combined matrix for both genera (Table IV). A phylogenetic analysis was conducted for thishybridized data set using the exact search Branch and Bound algorithm in PAUP.Three equally parsimonious trees with a tree length of 49, a CI of 0.90 (maximijm value= 1.00), and an RI of 0.96 (maximum value = 1.00) resulted. One tree preserved theparaphyly of Galeocerdo cuvier, as in the previously generated Kroyeria cladogram(Figure 110). One tree had the thresher shark, Alopias vulpinus and the mako, Isurusoxyrinchus both lamnids, tucked between the triakids and Galeocerdo cuvier resultingin the paraphyly of the carcharhinids and lamnids. The remaining tree that maintainedmonophyly of the aforementioned specific and supraspecific taxa was chosen (Figure114).The resultant tree accommodates both sets of parasite data (the additive binary170recoded cladograms from Kroyeria and Kroeyerina) with little conflict. The holocephaIan dade represented by Callorhynchus callorhynchus (Linnaeus, 1758) is the sistertaxon to the remaining elasmobranchs. The batoid dade composed of the generaMobula, Dasyatis, and Rhinobatus is the sister dade to the remaining components ofthe tree composed of the two lamnids, A/op/as and Isurus plus the remaining carcharhinids. Ga/eocerdo, previously showing a paraphyletic relationship with itself dueto the sharing of Kroyeria dispar and K. papi//ipes becomes a monophyletic entity heldtogether by the presence of Kroeyerina elongata Wilson, 1932.Also of interest is the placement of the blue shark, Prionace g/auca. In theKroeyerinacladogram (Figure 113) Prionace is basally placed in the carcharhinid-lamnid lineage, in the Kroyer/a-derived cladogram (Figure 111) Prionace was at the top ofthe cladogram, and the combined tree (Figure 114) (in fact all three of the combinedKroeyerina-Kroyeria trees) maintained this placement of Prionace. This placement ofPrionace is consistent with that of Compagno (1988) and Lavery (1992) in their morphologically- and molecular-based cladograms, respectively. The taxonomic or phylogenetic congruence (see Lanyon, 1993) amongst three independent data sets suggeststhat the presence of Kroeyerina e/ongata, on Prionace is a result of colonization fromGaleocerdo.Not mentioned in other studies however, the method used equally combinesparasite species from one genus with those from another genus to generate the hostcladogram. The more species a cladogram contains, the more nodes and branches orinformation the binary code must contain, resulting in a significantly longer binary stringin order to represent that topology. Having more character states in a parsimony analysis will functionally weight that set of data as graphically illustrated in this example.Serendipitously, this combination of data sets has almost no overlap. With allthe Kroyeria species restricted to the Carcharhiniformes, and Kroeyerina extendingover a broad range of host taxa, minimal character conflict or competition occurs,Although the specific results are not included in this effort, combining this hybriddata matrix composed of Kroeyerina and Kroyeria with the recoded Eudactyll;’7a cladogram resulted in thousands of rival trees with heavily conflicting topologies (data setmay be obtained from the author). Surveying hundreds of these trees revealed thateach tree possessed subsets of clades from each of the three data sets. Due to the differential possession (via sampling bias or extinction) of a given parasite group orgroups, members of putative host clades apparently well resolved in the independentanalyses would be ripped away from one another. The general problem here has beentouched upon superficially by Page (1994) and specifically herein by me. The problemis in the treating of parasites strictly as characters and not as lineages with their own171independent histories. Generating a host phylogeny with multiple parasite lineages thatare differentially possessed by the host complex under analysis is somewhat analogousto generating a copepod parasite tree based on the maxilliped from a couple of speciesof one genus, the antennae of another, and on the legs from yet another with only someof these characteristics overlapping across the taxa under study. The result will beuninterpretable noise and artifact at best. If cladists recognize that clades or lineages,have independent histories, then single parasite lineages are what cospeciation analyses should focus on. Despite this, informative analyses are possible if the parasitetaxa are restricted to: 1) a single lineage, 2) multiple parasite taxa equally distributedand weighted across the host axis, or 3) parasite lineages that occur in different hostlineages minimizing character conflict. This is nothing more than following the sameprotocol one follows in using typical character data. Point one is analagous to character state analysis of a single character, point two is the same as undifferentially usingall character data available from organisms, and point three is equivalent to synapomorphic or autapomorphic character data distributions. Therefore, though combined analyses may consolidate information into a single tree under the above conditions, cladograms may offer more information separately than when combined in other situations.Subsequent tree comparison or tree reconcilation methodologies can proceed from thatpoint. Of course tree comparison/reconciliation can be conducted with the parasite orassociate phylogeny directly, a parasite-derived host phylogeny need not be generateda priori.COMPETING HOST CLADOGRAMSThe several parasite-derived host cladograms generated herein function asindependent tests or hypotheses of other elasmobranch phylogenies previously reported in the literature.Two of the most comprehensive phylogenetic analyses of relationships of thesqualoids, squatinids, pristiophorids (Shirai, 1992a, b), and batoids (Nishida, 1990) arehybridized herein for comparative purposes (Figure 115), with the irrelevant or non-parasitized host taxa excluded. The topology is not as different as it appears compared tothat of Eudactylina-derived host trees (Figures 66 and 67). As previously mentioned,the Eudactylina-derived cladogram contains two distinct estimates of the host cladogram. One (read from left to right) bracketted by Manta and Mustelus, is essentially acarcharhinid dade with a host capture to derived epipelagic myliobatids. The otherbracketted by Squalus and Urolophus is a dade infecting the Squalea. The parasite-derived host tree corroborates Shirai’s (1992b) postulate of a paraphyletic assemblage172of shark-like squaloids, and the monophyly or existence of the hypnosqualea, consisting of Squatina as the sister taxon to the pristiophorid plus batoid dade. The parasitedata posits a more basal basal placement for Squalus relative to the etmopteridsAculeola and Etmopterus than does Shirai (1 992b).The batoid relationships from Nishida (1990) show genera (in ascending order)Torpedo, Rhinobatus, and Raja existing as a paraphyletic grade. The parasite-derivedhost tree suggests the possibility of monophyly for these respective taxa. In a somewhat complementary approach, Heemstra and Smith (1980) hypothesize a monophyletIc Raja plus Rhinobatus with Torpedo as the sister taxon to that dade. Nishida (1990)places both Dasyatis (Dasyatididae) and Urolophus (Urolophidae) as the sister group toGymnura (Gymnuridae) plus Myliobatis, Rhinoptera, Manta, and Mobula , hisMyliobatididae. The parasite-derived host tree is very similar except the group composed of ((Urolophus) (Gymnura, Dasyatis)) is the sister group to Myliobatis. The supposed horizontal transfer or colonization of the eudactylinid-infecting rhinopterid-mobulid dade from the carcharhinid lineage is congruent with the relationships proposed byNishida (1 990) with the exception that the parasite-derived host tree yields greater specific resolution between the sampled species of Mobula and Manta.With regard to carcharhiform relationships, a cladogram deduced and hybridizedfrom Compagno’s (1988) many cladograms and text is presented in Figure 116A. Anadditional cladogram derived from molecular data (Naylor, 1992) is presented in Figure11 6B. Again, non-parasitized host taxa have been excluded from the host trees. Keepin mind different host taxa are involved because many more squaloids and batoids hostEudactylina than do carcharhinids, many more carcharhinids host Kroyeria than do thesqualoids and batoids, and different sets of hosts were used from that herein, withCompagno’s (1988) and Naylor’s (1992) analyses. Host relationships derived fromEudactylina postulate an unresolved group composed of Chiloscyllium punctatum (ano recto Ic bid), Rhizoprionodon acutus, Carcharhinus brevipinna, Carcharhinus limbatus,and Sphyrna lewini to be the sister group to the rest of the tree; these four all harborE. aspera. The next carcharhiniform group is composed of triakids Mustelus andGaleorhinus. This is sister group to a dade composed of Galeocerdo which, with thedade of rhinopterid-mobulid colonizers removed, is sister taxon to a dade composed ofSphyrna which is the sister group to a small Carcharhinus dade. Additionally, if thehost association of E. aspera on the orectolobid, Chiloscylilum represents host-parasiteco-divergence, and if the other records of E. aspera indicate colonization of this speciesto those four carcharhinid hosts, then the parasite-derived host phylogeny closely parallels the hybrid host tree of Compagno (1988) (Figure 116A). The orectolobid is placedoutside the carcharhiniform group with the remaining galeomorphs. The triakid genera173Triakis, Mustelus, and Galeorhinus though shown to be monophyletic with the parasitetree, are hypothesized to be paraphyletic by Compagno (1988), even though heassigns them to Triakidae. Galeocerdo is the sister taxon to the sphyrnids and carcharhinids as in the Eudactylina-derived host tree. Interestingly, the host and parasite-derived cladograms show Sphyrna tiburo as sister taxon to S. lewini and S. mokarran.Additionally, both host morphological and molecular cladograms show Carcharhinusacronotus, well separated from the more closely related C. plumbeus and C. obscurus,while the Eudactylina-derived host cladogram (Figure 66) leaves the three as an unresolved polytomy. All three trees suggest C. obscurus and C. plumbeus are closelyrelated.The combined Kroyeria plus Kroeyerina-derived host cladogram (Figure 114)shows the holocephalan to be the sister group to the remaining members of the tree, orto all extant elasmobranchs as Maisey (1984a) has shown. The parasite-derived hostcladogram shows batoids to be removed from the next node and postulates sistergroup relationships of Carcharhiniformes and Lamniformes (Alopias and Isurus), asCompagno (1988) has suggested. The Kroyeria-Kroeyerina-derived host tree impliesthat the tiger shark, Galeocerdo cuvier is the most basally placed carcharhinid of thisdata set. Hence the Triakidae is situated between sphyrnids and Galeocerdo. Thisrelationship is not supported by the host morphology-based cladogram (Figure 116A) ofCompagno (1988), nor by the host molecular-based cladogram (Figure 116B) of Naylor(1992). This arises because of the many plesiomorphic character states found inKroyeria dispar and Kroyeria papillipes which are specific to Galeocerdo. Becausecladistic analyses form groups on shared derived characters (synapomorphies) there isa possibility of species or groups of species being split off near the base of a cladogrambecause plesiomorphic characters invoke no particular groupings (Lambshead andPaterson, 1986). Although there is much evidence placing Galeocerdo outside of themain body of Carcharhinus (see Compagno, 1988 and Naylor, 1992) it is currently recognized as a member of the Carcharhinidae.Lavery (1992) in his phylogenetic analysis of carcharhinids from Australia usingallozyme electrophoresis concluded Galeocerdo may be more closely related to sharksof the Hemigaleidae (weasle sharks), traditionally placed between the Triakidae andGaleocerdo (Compagno, 1988 and Maisey, 1984b). Compagno (1988) mentions thatlittle has been done to elucidate the relationships of Galeocerdo because of its distinctiveness and ubiquity which invites neglect. Applegate (1978) compared dental andexternal morphology of Galeocerdo with a few triakids. It also shares similarities withthe Hemeigaleidae with regards to the nasal fontanelles. Additionally, manyGaleocerdo characters (see Compagno, 1988 for a comprehensive list) are primitive174characters by virtue of comparison with hemigaleids, triakids, proscyllilds, scyliorhinids,and noncarcharhinoid sharks. Many of these characters make Galeocerdo a transitional form between hemigaleids and the subfamily Carcharhininae, and through hemigaleids the Triakidae (Compagno, 1988). Compagno (1988) adds several characters suchas the very short snout, serrated and anaulacorhizous teeth, caudal keels, basin-likerostrum, pits and keels in front of the anterior fontanelle, great size, massive jaws,Carcharhinus-like arrangement of dorsal and anal fins, and high vertebral number areprobably derived characters, suggesting that it is specialized away from its common origin with the rest of the carcharhinids but has evolved in parallel with the large macro-predatory species of Carcharhinus, Glyphis, Negaprion, and Prionace. Galeocerdo isprobably the most primitive living carcharhinid, and may be closer to the commonancestry of all carcharhinids than any other living member of its family. It is probablythe primitive sister group of all other carcharhinids plus the Sphyrnidae. If theseCarcharhinus-like characteristics are in fact parallelisms or homoplasies, and the aforementioned primitive characteristics are found in even more basally placed families(Proscylliidae and Scyliorhinidae) than the Triakidae, then perhaps the KroyeriaKroeyerina-derived host cladogram placing Galeocerdo below the Triakidae describesan accurate relationship not readily embraced by current ichthyologists. The most parsimonious explanation for the basal placement of Kroyeria dispar Kroyeria papililpes,and Kroeyerina elongata, in their respective genera is one of host-parasite co-divergence, not three independent host captures by three plesiomorphic parasites, furthercorroborating the unorthodox placement of Galeocerdo in the Kroyeria-Kroeyerinaderived host cladogram. In any case, Galeocerdo appears to remain somewhat of anenigma, basally placed within the Carcharhinidae or possibly even outside that family.The next dade of the Kroyeria-Kroeyerina-derived host cladogram (Figure 114)posits a monophyletic Triakidae with a monophyletic Triakis dade as the sister group toa dade composed of a paraphyletic Galeorhinus plus Mustelus. Host morpholgy(Figure 116A) depicts a paraphyletic grade consisting of, in ascending order Triakis,Mustelus, and Galeorhinus. A dade composed of ((Sphyrna mokarran)(Sphyrna lewini,Sphyrna zygaena)) is found next in the parasite-derived tree (Figure 114).Relationships among these sphyrnids are unresolved in the morphological and molecular cladog rams.The parasite-based tree suggests that Carcharhinus is paraphyletic, includingwith it Prionace, Negaprion, and Rhizoprionodon. This placement of Prionace is in general consistent with its placement in morphologically-based and molecular-based hosttrees. Furthermore, Negaprion is nested within Carcharhinus in the morphologicallybased tree, and Lavery (1992) reached a similar conclusion in an allozyme study of car-175charhinids. Morphologically-based and molecular-based trees treat Rhizoprionodon asexternal to Carcharhinus. This disc