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The morphology and cytology of Audouinella sp. (Rhodophyta, Acrochaetiaceae) Hymes, Beverly Joy 1981

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THE MORPHOLOGY AND CYTOLOGY OF AUDOUINELLA SP. (RHODOPHYTA, ACROCHAETIACEAE) by BEVERLY JOY HYMES B . S c , Univers i ty of Toronto A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES Department of Botany We accept th i s thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA A p r i l , 1981 (c) Beverly Joy Hymes, 1981. In presenting th is thesis in par t ia l fu l f i lment of the requirements for an advanced degree at the Univers i ty of B r i t i s h Columbia, I agree that the Library shal l make i t f ree ly avai lab le for reference and study. I further agree that permission for extensive copying of th is thesis for scholar ly purposes may be granted by the Head of my Department or by his representat ives. It is understood that copying or publ icat ion of th is thesis for f inanc ia l gain shal l not be allowed without my written permission. Department o f . The Univers i ty of B r i t i s h Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1W5 D E - 6 B P 75-5 1 1 E i i ABSTRACT Audouinella sp. (Rhodophyta, Acrochaetiaceae) was co l lected seasonally between May 1978 and Apr i l 1980 from the North Alouette River, B r i t i s h Columbia and occasional ly from other regions in B r i t i s h Columbia, Washington and Oregon states. The plants were attached to rocks, moss, or the freshwater red a lga, Lemanea. In general, macroscopic specimens were co l lected in the winter and spring and germlings in the summer and f a l l . Audouinella i s a uniser iate branched fi lament with erect and basal systems. The basal system pers is ts most of the year. Each ce l l contaihs one par ie ta l chloroplast which varies from sp i ra l to i r r egu la r l y band shaped; pyrenoids are absent. Large l i p i d bodies of unknown function are common in most ce l l s of f i e l d and cultured material and tend to aggregate near the p i t plugs. Hair c e l l s and monosporangia are commonly found on the t ips of short branches. Regeneration of the monosporangia, hair c e l l s and f i l a -ments i s common. Sexual reproduction was not observed. Growth and elongation, observed with the aid of ca lcof luor white ST, i s l imi ted to the apical c e l l s of the main axes, branches and branchlets. Morphological p l a s t i c i t y i s evident in the varying ce l l s izes obtained from f i e l d and cultured material at d i f fe rent l i gh t i n t ens i t i e s . Four chromosomes represent the haploid condit ion; there are two larger (ca. 0.4 ym) and two smaller (ca. 0.3 ym) chromosomes. Audouinella sp. has typ ica l red algal u l t ras t ruc tura l features. Un ice l lu la r hairs are described u l t r a s t ruc tu ra l l y in the red algae for the f i r s t time. They contain a prominent nucleus, several mitochondria, endoplasmic ret iculum, golgi bodies and many ves ic les . Chloroplasts or proplast id type of organelles are absent. Audouinella sp. was compared to 24 descr ipt ions of other freshwater members of the Acrochaetiaceae and i t was concluded that at present i t i s not possible to provide a species name for the plant observed in th i s -study. The generic name Audouinella was chosen in agreement with current taxonomic studies. Dedicated in loving memory to my uncle Charles Abramson and to my aunt El l i e Hymes. V TABLE OF CONTENTS Page ABSTRACT i i LIST OF TABLES v i i LIST OF FIGURES v i i i LIST OF APPENDICES ix ACKNOWLEDGEMENTS x I. INTRODUCTION 1 A. TAXONOMIC STUDIES 4 B. PREVIOUS STUDIES OF THE ACROCHAETIACEAE 7 I I . MATERIALS AND METHODS 10 A. NATURAL POPULATIONS 10 B. CULTURES 11 C. LIGHT MICROSCOPY 12 D. ELECTRON MICROSCOPY 13 E. CHROMOSOMES 14 F. PRELIMINARY GROWTH STUDY AT DIFFERENT LIGHT INTENSITIES . . . . 14 G. OTHER EXPERIMENTS 19 I I I . RESULTS 20 A. FIELD COLLECTIONS OF AUDOUINELLA SP 20 B. CYTOLOGICAL OBSERVATIONS OF FIELD AND CULTURED MATERIAL 24 C. CHROMOSOME COUNTS AND CELL DIVISION 27 D. PRELIMINARY STUDIES ON THE GROWTH OF AU. SP. AT DIFFERENT LIGHT INTENSITIES 29 E. SPECIES DESCRIPTION 30 IV. DISCUSSION 31 A. TAXONOMY 31 vi B. MORPHOLOGICAL PLASTICITY 33 C. SEASONALITY 34 D. CYTOLOGY 35 E. HAIR CELLS 36 F. MONOSPORE RELEASE AND REGENERATION 39 G. CHROMOSOMES 3 9 H. GROWTH USING CALCOFLUOR DYE 4 1 I. CONCLUSION 41 V. LITERATURE CITED 42 VI. APPENDIX 75 v i i LIST OF TABLES Table Page I. Samples of Audouinella sp. co l lected from the North Alouette River, B. C 16 I I . Co l lect ions of Audouinella sp. from outside the North Alouette River study area 17 I I I . Composition of Enriched A r t i f i c i a l medium g .1" 1 18 IV. Cel l measurements 21 v i i i LIST OF FIGURES Figure Page 1-5. Light micrographs of the basal and erect systems 53 6-9. L ight micrographs of the erect system 54 10-12. U l t rast ructure of ce l l cross-sect ions 55 13-16. U l t ras t ructura l features of the c e l l s showing ch loroplasts , 56 nucleus and f lor idean starch deposits 57 17-21. Fine structure of mitochondria, golgi bodies, endoplasmic reticulum and l i p i d deposits 58 22-26. L i p id bodies in ce l l s of the erect axis 59 27-31. Monosporangia and hair c e l l s 60 32-40. Monosporangia and germination of the monospore 61 41-43. Ul t rastructure of empty monosporangia 62 44-46. Hair c e l l s 63 47-48. Fine structure of hair c e l l s 64 49-52. Fine structure of hair c e l l cross-sect ions 65 53-57. U l t rast ructure of p i t plugs and ce l l wall features 66 58-60. Fine structure of the nucleus and blue-green epiphyte 67 61-66. Unusual ce l l features in cultured material 68 67-72. Cel l d i v i s i on in c e l l s of the erect axes 69 73-79. Ce l l d i v i s i on in ce l l s of the erect axes 70 80-84. Growth using ca lcof luor white ST as a label 71 85-88. Growth of the main axis and branch c e l l s 72 89-92. Growth using ca lcof luor white ST as a label 73 93. Number of new ce l l s vs day 74 94-95. Length of new t i p c e l l s and the ce l l below the t i p vs day . . . 75 i x LIST OF APPENDICES Page A. Twenty-seven descr ipt ions of freshwater members of the Acrochaetiaceae 75 X ACKNOWLEDGEMENTS I am deeply indebted to Dr. K. M. Cole f o r her extreme pa t ience and constant encouragement. The p leasan t atmosphere she c rea tes i n her l ab i s o f much b e n e f i t to everyone and her en joyab le ' t e a ' sess ions w i l l always be remembered. I would a l s o l i k e to thank Dr. J . R. S t e i n f o r her help throughout the course of t h i s work. Thanks to Drs . P. J . Har r i son and R. E. DeWreede f o r read ing the t h e s i s and g i v i n g me he l p fu l sugges t ions . A spec i a l thank you to Dr. R. G. Sheath who in t roduced me to f reshwater red a l gae . F i e l d c o l l e c t i o n s cou ld not have been pos s i b l e w i thout the he lp o f D. MacDonald, H. Contant , M. Chamberl in and H. Vandermeulen. C. Parke a s s i s t e d me w i th some o f the chromosome work and sus ta ined me w i th her bak ing . I am g r a t e f u l to Dr. D. Garbary f o r p rov i d i ng l i t e r a t u r e , Dr. C. M. Pueschel f o r a s s i s t ance w i th EM m a t e r i a l , J . van Ve lzen f o r t r a n s l a t i n g German papers and Fay French f o r t yp ing the manuscr ip t . I would a l s o l i k e to thank Herb Vandermeulen f o r h i s f r i e n d s h i p and a s s i s t ance w i t h many aspects o f t h i s t h e s i s . I am a l s o very g r a t e f u l to my paren ts , my aunt Go ld ie Abramson and a l l my f r i e nd s f o r t h e i r support and unders tand ing. The work f o r t h i s t h e s i s was supported by N.S .E .R .C . ope ra t i ng grant 670645, an N.S .E .R .C . graduate f e l l owsh i p and a U.B.C. f e l l o w s h i p . 1 INTRODUCTION The red alga Audouinella Bory (1823) i s a member of the family Acrochaetiaceae (Florideophyceae, Nemaliales). This family of plants comprises 200 - 300 marine and freshwater species. Genera included in 1 2 •• 3 the family are; Audouinella , Acrochaetium Nageli 1861, Rhodochorton Nageli 1861, Balbiania Sirodot 1876, Colaconema Batters 1896, Ky i in ia Rosenvinge 1909, Chromastrum Papenfuss 1945, Grania (Rosenvinge) Kyi in 1944, L iagorophi la Yamada 1944, Rhodothamniella Feldmann 1954 and Chantransia Desvaux 1809 (see Drew 1928; Woelkerling 1971, 1973; Garbary 1979a). Members of the Acrochaetiaceae consist of smal l , uniser iate branched/ unbranched f i laments. Several growth forms are apparent in th i s group; plants may be composed of both basal and erect systems; a well developed basal system but almost no erect system; a basal system composed of a loose aggregation of f i laments and a well developed branching erect port ion; and a basal system consist ing of one ce l l only and an elaborate system of erect axes. In some plants rh izo ids occas ional ly extend down-ward from the bases of the erect axes. The algae vary from ca. 20 ym to 10 mm in height. Their colour ranges from dark stee l-b lue to green to v io le t - red to rose. The chloroplasts may be d i sco id , elongate, lobed, sp i ra l or s t e l l a t e in shape and they may be e i ther par ieta l or a x i a l . There can be one to many ^abbreviated Ay., in text 2 abbreviated Ac., in text 3 abbreviated R.in text 2 chloroplasts per ce l l and they may or may not contain pyrenoids. There i s always one nucleus per c e l l . Much confusion occurs in the taxonomy of th i s group because one species can have several of the morphological forms described above. Reports of sexual reproduction in the Acrochaetiaceae are rare but asexually developed monosporangia are common. Cytological behaviour during sporangial formation i s poorly known. Tetrasporangia can be formed me io t i ca l l y , apomeiotical ly or possibly m i t o t i c a l l y . Gametangial p lants, when present, can be e i ther monoecious or dioecious. Spermatangia are formed s ingly or in c lus ters . The carpogonial branch i s un i ce l l u l a r and the carpogonia are terminal , l a te ra l or in terca lary . After fusion the carpogonium does not associate with an aux i l i a r y c e l l ; i t develops d i r e c t l y into a carposporophyte. Some of the species produce a "carpotetrasporophytic" generation. Members of the Acrochaetiaceae appear to have exploited a very wide range of the environment and have adapted to many d i f fe rent niches. Plants grow in f resh, marine or brackish water; epiphyt ic on moss, water plants or other algae; endophytic; endozoic; e p i l i t h i c or ep ipe l i c . Some of the f r ee - l i v i ng marine species grow high in the i n t e r t i da l region, on rocks in damp well shaded areas; the endozoic,endophytic, and epiphytic marine species are found throughout the in te r t i da l . and subtidal regions (Dixon and Irvine 1977). The freshwater species are usual ly found in co ld , c l ea r , fast-running streams and r ivers in shaded areas attached to rocks, submerged mosses or other species of red algae Lemanea and Batrachospermum (Skuja 1938). Occasional ly these species grow in more open, l ighted areas in muddy brown, slower moving streams (D i l l a rd 1966). 3 Complete circumscript ions of th i s family have been recorded by Drew (1928), Papenfuss (1945), Kyi in (1956), Woelkerling (197i, 1973) and Garbary (1979a). 4 A. TAXONOMIC STUDIES Some of the f i r s t descript ions of plants in the Acrochaetiaceae involved the freshwater members. The generic name Chantransia was f i r s t used in 1805 by De Candolle in the Flore Francaise (p. 49) ( in Drew 4928). However i t was shown la te r by other workers (for deta i l s see Drew 1928) that a l l eight species he described belonged to other groups of algae and hence they were renamed. Desvaux (1809) and Fr ies (1825) both used Chantransia as a generic name to describe other species and therefore the name s t i l l e x i s t s . Desvaux (1809) l i s t e d Chantransia hermanni (Roth) Desvaux (=Conferva  nermanni Roth) growing on Lemanea incurvata Bory. Fr ies (1825) referred to two freshwater forms, Chantransia hermanni (Roth) Desvaux and Chantransia chalybea (Roth) F r i es . The name Chantransia has been con-sidered by Drew (1928) and Papenfuss C,1945) to be nomenc la tura l l y inva l id "since a l l the species o r i g i na l l y included in the genus Chantransia have been removed permanently to other genera" (Drew 1928). Today the word chantransia i s often used to denote the alternate phase of the l i f e h istory of Batrachospermum, Lemanea and other freshwater red algae. Recently, Starmach (1977) used the genus Chantransia in his F lora of Poland (Flora Slodkowodna Po lsk i ) and described a l l the freshwater members under this- name. The genus Audouinella was f i r s t described by Bory(1823) for the freshwater red a lga, Audouinella mihiata [=Audouinella hermanni i(Roth) Duby, 1830]. This genus has been accepted today by several workers as being the oldest va l i d name that can be applied to members of the Acrochaetiaceae (Papenfuss 1945, Woelkerling 1971, Dixon and Irvine 1977 5 and Garbary 1979a). Nageli (1861) described the marine genera Rhodochorton and Acrochaetium, the former reproducing by tetraspores and the l a t t e r by monospores. Balbiania was introduced by Sirodot (1876) for the freshwater species that reproduced sexual ly. The other genera in the Acrochaetiaceae include names that have been applied to marine species only and the i r or ig ins w i l l not be discussed in d e t a i l . Drew (1928) proposed that a l l members in the Acrochaetiaceae be included under the generic name Rhodochorton, the older name described (Nageli 1861). She considered that the morphological charac ter i s t i cs used to separate the d i f fe rent genera were unsat isfactory and caused confusion. However, Rhodochorton was not the oldest ep i thet , as previously stated. Papenfuss (1945) suggested that chloroplast type could be used as the chief c r i t e r i on for d is t inguish ing the genera. The group was then resolved into four c learcut genera: Rhodochorton, containing a few to many smal l , d isco id chloroplasts per c e l l ; Acrochaetium, containing one par ieta l or laminate chloroplast per c e l l ; Audouinella containing one or more sp i ra l ch lorop las ts per c e l l , t h i s includes marine and freshwater genera; and Chromastrum containing one or more s t e l l a t e chloroplasts per c e l l . The remainder of the genera were synonymized with above four genera. Papenfuss (1947) subsequently replaced Chromastrum with Ky i i n i a , the older epithet containing one or more s t e l l a t e ch loroplasts . Kyi in (1956) separated the marine and freshwater genera and recognised Audouinel la, Ky i i n i a , Acrochaetium, Grania, Rhodochorton, Colaconema, Liagorophi la and Conchocelis. Each was separated by habit , chloroplast type, means of reproduction (tetraspores vs. monospores; some sexual reproductive features) and habi tat . Audouinella was recognised as the only freshwater genus containing par ieta l chloroplasts which were more or 6 less band-shaped with i r regu lar margins. Feldmann (1962) also separated the marine and freshwater genera, and in agreement with Chemin (1937), two fami l ies were recognised, the Acrochaetiaceae and the Audouinellaceae, and eight genera were accepted. The fami l ies were circumscribed based on several features: the development of the gonimoblast, charac te r i s t i c s of the ch lorop lasts , and e i ther a haplobiontic or d ip lob iont i c l i f e cyc le . The d i f fe rent genera were separated based on po s t - f e r t i l i z a t i o n charac ter i s t i cs of the carpogonium. Bourrel ly (1970), who did not agree with Drew (1928), chose to fol low th i s c l a s s i f i c a t i o n scheme and he recognised three freshwater genera, Audouinel la, Balbianiaand Acrochaetium. Audouinella contained a few par ieta l r ibbon- l ike ch lorop lasts , and reproduced both sexual ly and asexual ly. Balbiania was separated from Audouinella because i t had a protothal lus growth phase, several par ie ta l chloroplasts and a transverse d i v i s i on in the carpogonium fol lowing f e r t i l i z a t i o n . Acrochaetium was separated from Balbiania and Audouinel!a because i t contained only one par ieta l band-shaped chloroplast and sexual reproduction was unknown. Woelkerling (.1971), Dixon and Irv ine (1977) and Garbary (1979a) a l l agreed with Drew that i t i s not va l i d to separate the plants into d i f ferent genera based on morphological features. Woelkerling (.1971) placed a l l species with sexual reproduction in the genus Audouinella and those with-out in the genus Cblaconema. Ky i in ia and Liagorophi la were not examined and the i r d i s t i n c t i on as genera remained questionable. Dixon and Irv ine (1977) and Garbary (1979a), recognizing only the family Acrochaetiaceae, assigned a l l members into the genus Audouinel la. Garbary (1979a, b) reached his conclusions by using numerical taxonomy, culture studies and a l i t e ra tu re review. As Drew (1928) and Woelkerling 7 (1970, 1971) he found that at the generic level morphological and reproductive charac ter i s t i cs were unre l iab le for use in taxonomy. He did not include de ta i l s of po s t - f e r t i l i z a t i o n because they are not known for most of the genera in th i s group. In th i s thesis I am fol lowing the generic concepts of Dixon and Irvine (1977) and Garbary (1979a) and have c l a s s i f i e d the freshwater plant that I have studied into the genus Audouinel la. B. PREVIOUS STUDIES OF THE ACROCHAETIACEAE AND INTENDED RESEARCH A l l taxonomic names given in the remainder of th is thesis w i l l be those used by the author of the paper quoted. For any emendations of the names see Woelkerling (.1971 , 1973), Dixon and Irvine (1977) and Garbary (1979a). The f i r s t freshwater genera described in the Acrochaetiaceae were from f i e l d co l lected and preserved samples. Murray and Barton (.1891) described sexual reproduction from f ixed material of Chantransia boweri Murray and Barton. Drew (1935) did seasonal co l lec t ions of Rhodochorton  violaceum (Kiitz.)Drew and described i t s morphology and sexual reproduction. Subsequently Drew (.1936) considered C_. boweri and R. violaceum as synonymous (both=Au. hermanni). Jao (1940, 1941) described the freshwater members from f i e l d co l lec t ions in China and reported four new species (see Appendix Table I ) . New freshwater species of Acrochaetium and Rhodochorton have been reported from f i e l d co l lected material in India, Venezuela and Japan (Raikwar 1962; Khan 1970; Patel 1970; D'LaCoste and Ganesan 1972; Kumano 1978). Swale and Belcher (1963) were the f i r s t to describe the l i f e h is tory of 8 a freshwater member from f i e l d and culture material (Rhodochorton  invest iens (Sirodot) Swale and Belcher). The remaining l i f e h istory and culture studies have been on marine species only. Knaggs (1965a, b, 1966a, b, 1967a, 1968) and Knaggs and Conway (1964) examined R. f lor idulum (Dil lwyn) Nag. and R. purpureum ( L i gh t f . ) Rosenvinge from B r i t a i n using f i e l d and culture mater ia l . The l i f e h i s to r ies of both species were ascertained and the morphology of P*. purpureum was studied in re la t ion to i t s environment (Knaggs 1966a, b). On the west coast of North America several cul ture studies of marine species in the Acrochaetiaceae were done by West. He observed the morphology and reproduction of Acrochaetium pectinatum (Kyi in) Hamel (West 1968); R. purpureum and JR. tenue Kyi in (West 1969 1970a); R. concrescens Drew (West 1970b) and JR. membranaceum Magnus, West (1979). In cul ture the algae were subjected to d i f fe rent temperatures and photo-periods. Using l i gh t microscopy West also studied the environmental control of the development of hair c e l l s and sporangia in Ac. proskaueri West (.1971) and the regulat ion of asexual reproduction in R. purpureum (1972). Stegenga (1978), Stegenga and Borsje (1976, 1977), Stegenga and Vroman (1976) and Stegenga and VanWissen (1979) observed the l i f e h i s to r ies of several European marine species of Audouinel la. Plants were grown at d i f fe ren t l i gh t and temperature conditions and observations were made using the l i gh t microscope. Garbary and Rueness (1980) described the l i f e h is tory of a new species Audouinella tetraspora Garbary and Rueness in cu l ture. A few other morphological studies on marine members have been done. Pearlmutter and Vadas (1978) observed regeneration of tha l lus fragments of 9 R_. purpureum in cu l ture , and Garbary (1979b) studied patterns of ce l l elongation and the ef fects of temperature on the growth and morphology of some Audouinella spp. In the Acrochaetiaceae there have been few u l t ras t ruc tura l and cyto-log ica l studies. L i ch t l e (1973a, b) invest igated the f ine structure of the chloroplast and i t s degeneration in R_. purpureum. Observations of the p i t plugs of four species were reported by Lee (1971) and others by Pueschel and Cole (1981 pers. comm.). A few cyto logica l observations were done by Magne (1964), Woelkerling (1970) and West (1969, 1970b). Because there i s a dearth of cyto log ica l information and chromosome counts in the Acrochaetiaceae, plants were co l lected and f ixed in order to study ce l l structure and count the chromosomes. Cel l measurements of f i e l d and cultured material were recorded for the determination of morphological p l a s t i c i t y . Experiments were also set up to observe the ef fects of d i f fe rent l i gh t i n tens i t i e s on the growth of Audouinel la, as previous workers had done (West 1972, Garbary 1979b). The complete descr ipt ion of Audouinella obtained in th i s study was compared to 24 other descr ipt ions of freshwater algae in the Acrochaetiaceae in order to provide an accurate species name for the plant. 10 I I . MATERIALS AND METHODS A. NATURAL POPULATIONS Audouinella sp. from the lower portion of the North Alouette River in the munic ipa l i ty of Maple Ridge, B r i t i s h Columbia; 49° 122° SW was co l lected in a shaded area close to the r i ve r bank at the point where the r i ve r meets 232nd Street (Table I ) . Wehr (1979) described the cl imate of th is area as a warm maritime-mesothermal type which i s humid to rainy. Snow i s infrequent although ra in i s common during the winter months. The r i ve r is located in the Coastal Western Hemlock Biogeoclimatic zone (Wehr 1979). The North Alouette River is a fas t flowing r i ve r and there i s l i t t l e ice cover during the winter. The r i ve r i s s l i g h t l y ac id i c with pH ranging between 6 and 7 (Wehr 1979). Specimens were co l lected from natural populations f a i r l y regular ly between May 1978 and Apr i l 1980 (Table I) and the temperature and the pH of the r i ve r were also recorded each time (Table I ) . In the North Alouette River Au^ . sp. was attached only to rock surfaces. Wehr (.1979) noted that the rocks in the streambed are acid g ran i t i c and consist large ly of quartz d i o r i t e , d i o r i t e and gabbro. No preference to rock surface was noted but plants were found on rocks in shaded areas only. The plants were ca re fu l l y removed from the rocks; some were f ixed immediately for electron microscopy and cyto log ica l work and others were brought back to the laboratory on ice for examination and cu l tu r ing . Other co l l ec t ions of Au_. sp. were made in June 1978 by Dr. R. Sheath during a f i e l d t r i p in the states of Washington and Oregon (Table I I ) . The plants in the streams were epiphyt ic on mosses and the freshwater 11 alga Lemanea. Two populations of Au. sp. were co l lected from other areas in B r i t i s h Columbia (Table I I ) . A l l of these plants were observed and compared to Au. sp. from the North Alouette River; some were f ixed for electron microscopy and others were grown in cul ture (Table I I ) . Cel l measurements were obtained from most of the natural populations co l lected throughout the year. The majority of the measurements were done in Apr i l through June. Measurements of c e l l s in d i f fe rent plant parts were taken in order to compare th i s plant with descr ipt ions of other freshwater red algae in the Acrochaetiaceae and to show the s ize range that can be obtained for one species. Most of the data were rep l icated a minimum of ten times. Plant parts were designated as fo l lows: a) main axis = a row of c e l l s greater than ten in number, not terminating in hair c e l l s or monospores. b) secondary axis = la tera l branches, less than ten c e l l s , sometimes terminating in monosporangia or hair c e l l s . c) monosporangia. d) hair c e l l s . The s ize range, mean and standard deviat ion were calculated for each part. B. CULTURES The medium which produced the best growth of th is alga consisted of a combination of various a r t i f i c i a l s a l t s , so i l water and vitamins (Table II I) (Sheath and Cole 1980). Several clumps of plants (the number varied depending on the co l lec t ion) were teased apart and placed into p las t i c petr i dishes, 100 x 20 mm (Opti lux 1005) containing ca. 35 ml of medium and were then placed on a shaker (.91 shakes/min., each shake = 5.6 cm) 12 in a 5°C l ighted incubator. The growth chamber was maintained on a 12:12 L:D cyc le . In order to reduce irradiance paper towel l ing was placed on top of the petr i dishes. Hence the algae were exposed to ca. 2 1 6 yEin-m ,-s . A l l i rradiances were recorded using a LiCor Quantum Meter Model L.I.-185A. Plants that were removed from the shaker and kept on a she l f in the chamber grew poorly and began to senesce. In order to observe regeneration and to i n i t i a t e faster growth, plants in cu l ture (co l lected 18 May and 1 3 Ju ly 1978 from the North Alouette River and 24 June 1978 from the r i ve r north of Humptulips, WA; see Tables I and II) were removed, chopped with a razor blade into small pieces 5-10 c e l l s long and then placed into petr i dishes containing fresh medium. The cultures were maintained under the same condit ions as out l ined above. C. LIGHT MICROSCOPY L iv ing material from the North Alouette River and cultures were observed using a regular d issect ing microscope and a compound microscope. In order to detect some of the c e l l u l a r de ta i l s an Olympus microscope with the Hoffmann modulation contrast system was also used. Samples of cultured material were f ixed for l i gh t microscopy using the J .B . -4 methacrylate embeddment technique (Polysciences Inc. Warrington PA 18976). Filaments were f ixed in 2.5% glutaraldehyde buffered in phosphate (pH 7.2) for two hours at 4°C, r insed in buffer and d i s t i l l e d water followed by dehydration in methanol plus 0.5% NaCl in increasing increments from 25 to 100% alcohol . I n f i l t r a t i o n was done using the technique out l ined in the J .B. -4 k i t . Sections 4.0 ym thick were cut 13 using glass knives and a J .B . -4 Porter Blum microtome. Sections were stained with per iodic ac id- S ch i f f ' s (PAS) (Jensen 1962), counterstained with an i l i ne blue (PAS/AN) and mounted permanently with Euparal (supplied by Gurr, England). D. ELECTRON MICROSCOPY Samples of Au. sp. to be examined with the electron microscope were f ixed for two hours in 2% glutaraldehyde/phosphate buffer (pH 7.2) at 4°C. The plants were then washed with phosphate buffer 3-4 times at ten minute in te rva l s . Pos t - f i xa t ion followed using 1.5% osmium tetroxide/ phosphate buffer at 4°C. The material was then washed again in several changes of buffer. The buffer was washed out with d i s t i l l e d water in three stages. Dehydration followed using a graded ser ies of a lcoho l -acetone or jus t acetone. A l l specimens were embedded in a 4-step i n f i l t r a t i o n of Spurr 's low v i scos i ty res in and hardened for 12 h at 70°C (Spurr 1969). Sections were cut using glass knives or a Guido Sasso diamond knife on a Reichert Ultramicrotome OmU 3. Sections were picked up on carbon coated copper grids of various mesh s i zes , stained for 45 min with a saturated so lut ion of uranyl acetate, washed and then stained with lead c i t r a t e (Reynolds 1963) for 10-20 min. Sections were viewed with a Zeiss EM 10 electron microscope. Cultured material from the North Alouette River was exposed to a -2 -1 higher l i gh t in tens i ty , ca. 36 yEin-m -s , for 4 wks. Germinated monospores were then removed from culture dishes with a micropipette and f ine tweezers and then f ixed for electron microscopy according to the 14 above techniques. E. CHROMOSOMES For the study of chromosomes, plants from both natural populations a cultured material were f ixed in Carnoy's f l u i d I consist ing of 3:1 absolute ethanol:glacia1 acet ic acid (3:1; Sharma and Sharma 1965). In some species of red algae, ce l l d i v i s i on in cul ture occurs between the end of the l i gh t cycle and the beginning of the dark cycle (Cole pers. comm.). Therefore in an attempt to l o ca l i se ce l l d i v i s i on , plants of ALK sp. were removed and f ixed every 10 min, one hour before the dark cycle began and one hour a f ter (plants were growing on a 12:12 L:D cyc le ) . The alga was also maintained on a 24 h l i gh t cycle for one week and then f ixed at one half hour in terva ls one hour before the l i gh ts were switched of f in the incubator and one hour a f te r . Filaments were stained with wittmann's aceto-iron-haematoxyl in-chloral hydrate solut ion (Wittmann 1965). F. PRELIMINARY GROWTH STUDY AT DIFFERENT LIGHT INTENSITIES In order to assess the growth of Au^ . sp. the ca lcof luor white f luorescent technique of Cole (.1964) was used. Calcof luor White ST (.4,4'-bis [4-ani l ino-6-bis(2-hydroxyethyl)amino-s-tr iaz in-2-y lamino]-2,2 ' s t i l bened i - su l fon i c acid) was discovered to bind to the ce l l wall of plants because of i t s a b i l i t y to hydrogen bond with g-1,4 and 3-1,3 polysaccharides (Haigler et a l . 1980). Plants were exposed to 0.01% Calcof luor White ST (Cyanamid Can. Inc. Baie d'Urfe P.Q.) added to 15 culture medium for 24 and 48 h al lowing the dye to bind with ce l l wall mater ia l . Each plant was then washed several times in fresh medium and set up under experimental condit ions. Any new growth of the alga should not be labe l led with the dye unless the ce l l wall already formed contributed to the production of new ce l l wall mater ia l . Petr i dishes containing labe l led plants in normal cul ture medium were placed on a shaker in a growth chamber at 5°C on a 12:12 L:D cyc le. T r i p l i c a t e samples were set up at three d i f fe rent l i gh t i n tens i t i e s : -2 -1 l i gh t in tens i ty A- f u l l l i gh t 35 , yEin-m -s ; l i gh t in tens i ty B- under -2 -1 paper 6 pEin-m -s ; complete darkness. Portions of the plants were removed randomly at various in terva ls and observed using a Wild M20 fluorescence microscope (blue l i g h t ) . New plant growth was not labe l led with the dye and did not f luoresce. The white secondary fluorescence induced by the dye was easy to d is t ingu ish from the red primary f luores-cence of the chlorophyl l wi th in the ch loroplasts . New ce l l s were counted, measured and photographed using Tr i-X f i lm at 4 min exposures, as out l ined by Waaland and Waaland (1975). Ten d i f fe rent f i laments were observed each time and 10-15 ce l l s were measured. TABLE I . Samples of Audouinella sp. col lected from the North Alouette River, B. C. (see text for de ta i l s ) Co l lect ion pH Temp. Presence of: Culture °C ALL sp. Hairs Monospores Number 1978 18 May - - +++ + + Rl 13 July - - +++ + + _ 15 Sept. - - + - - -29 Sept. - 12.7 - - - -23 Nov. - - +G + - _ 2 Dec. - - +G - - _ 1979 11 Jan . i 5.4 1.5 +++ + + R2 15 Feb.* 5.7 2.5 +++ + + R3 20 Mar.+ 5.5 5.2 ++E + + R4 9 May 4.4 11.2 +++ + + -21 May - 11.0 +++ + + -21 June+ 7.1 9.4 ++E + + _ 19 July - 19.7 ++E + + -15 Aug. 5.8 - +G - - -1 Nov. 6.9 7.0 +G + - _ 1980 2 Jan. 6.0 5.0 +G - - _ 25 Jan. 5.6 2.0 +G + + _ 22 Apr i l 6.2 9.0 ++ + + R5 cn ^prepared for EM; +, +++=relative quant i t ies; -=no data or structure absent; G=present in a germ!ing state; E=algae heavily epiphytized. 17 TABLE I I . Col lect ions of Audouinel!a sp. from outside the North Alouette River study area (made in June 1978 by Dr. R. Sheath). Co l lect ion 1978 20 June Satiam R. at Hwy 22, Oregon 21 June Umpqua R. at Hwy 138, Oregon 21 June Rock Creek at 138, Oregon *'23 June Neskoun Crk. at Hwy 101, Oregon *'24 June River a few miles north of Humptulips, Wash. *25 June Lake Creek at Hwy 101, Wash. 13 July Kanaka Crk. B. C. 1979 1 Sept. River 19 miles from Bamfield B. C. S i te Descript ion Temp. OC epiphyt ic on moss at r i ve r bank, slow flowing 8.5 epiphytic on Lemanea at r i ve r bank, par t ly shaded 12.5 ephiphytic on Lemanea near bank on shoulders at water surface 16.5 epiphyt ic on Lemanea in middle of r i ve r 11.0 epiphytic on moss under tree overhang at r i ve r bank 12.8 epiphyt ic on Lemanea throughout r i ve r 16.0 e p i l i t h i c e p i l i t h i c in shaded area at r i ve r bank River Velocity^ cm*s - l 16.9 90.5 54.5 120.4 90.5 36.8 * = f ixed for EM; 1 = grown in cu l ture; 1 = average of two recordings. 18 TABLE I I I . Composition of enriched a r t i f i c i a l Medium g 1 ! - (Sheath and Cole 1980) SALT 9 .1" 1 NaCl 0.028 KC1 0.007 MgS04.7H20 0.07 MgCl 2 '6H 20 0.04 CaCl 2-2H 20 0.015 NaHC03 0.16 + 50 ml so i l extract (Provasol i 1968) + 20 ml ES stock so lut ion (Provasol i 1968) + 1 ml vitamin so lut ion (Provasoli 1968) 19 6. OTHER EXPERIMENTS Audouinella sp. was also grown in media of varying s a l i n i t i e s using the same technique as out l ined for the l i gh t in tens i ty experiment. A r t i f i c i a l seawater and freshwater media were used and four d i f fe rent conditions were set up, 0.6%* 0.9%c 15.51, 27.6%0(Sheath and Cole 1980). After 28 days plants in a l l four experimental condit ions were growing. However the plants in medium of 27.6%, produced smaller c e l l s and growth was slower. Due to contamination the experiment was discontinued and i t i s not included in the resu l t s . 20 RESULTS A. FIELD COLLECTIONS OF AUDOUINELLA SP. Material co l lected from the North Alouette River between May 1978 and Apr i l 1980 w i l l be described according to the season in which i t was obtained. The ce l l measurements referred to in th is section are presented in Table IV. During the f a l l (September through November ) Au^ . sp. co l lected in rock scrapings was in microscopic form only; the overal l development was very poor. The r i ve r temperature averaged 9.9°C and pH 6.9 (Table I ) . Green filamentous algae (CJedogoniales, U lo t r i cha les ; for deta i l s see Wehr 1979) were abundant in the r i ve r during the f a l l and in most cases the germlings were mixed with these green algal mats. Small germlings were found with erect f i laments growing out in a runner- l ike fashion from a cushion of basal c e l l s (F ig . 1, 2). Ce l l s of the erect axis ranged in length from 12 to 38 ym and the i r diameter from 5 , to IT , ym. The basal system consisted of many interwining fi laments (F igs. 3, 4). In general the c e l l s of the basal system were smaller than those of the erect axes, with ce l l lengths ranging from 8 to 19 ym and ce l l diameters from 4 to 14 - ym. Monosporangia did not develop but branches with/without hair c e l l s developed even when germlings were only 9 c e l l s long (F ig . 5). These hair c e l l s varied in length from 16 , to 74 ym and the diameter at the base of the c e l l s was 2 ym. In the winter (December through February) and the spring (March through Ap r i l ) growing macroscopic plants were abundant (F ig . 6). Winter water temperatures averaged 3.8°C and pH 5.7 (Table I ) . A current reading TABLE IV. Cel l measurements (ym, n=10-20) Plant Germlings (North Alouette River) August through November & Jan. 1980 erect axes basal c e l l s length range 12-38 8-19 mean 25.9 14.2 sd 12.83 5.08 diameter range 5-11 4-14 mean 8.07 11.16 sd 3.33 5.93 Adult Plants (a l l co l lec t ions) May 1978 through to July 1979 main axes secondary axes monosporangia hair c e l l s +spores -spores 27-65 38-50 15-19 11-19 16-243 46.3 41.8 16.6 13.5 94.6 11.0 5.37 1.7 1.97 68.83 9-19 8-11 11 8-11 2-6 12.0 10.3 11 9.34 5.0 3.13 1.85 0 1.89 1.38 22 of 73 crtirs - (average of three readings) was recorded for 15 February 1978 (Wehr 1979). During the winter of 1979, many healthy macroscopic plants were observed. The measurements of various ce l l parts and the appearance of the hair c e l l s and monosporangia were s im i la r to those found in the spring co l lec t ions (Table IV). However, heavy f looding during la te December 1979 and ear ly January 1980 resulted in an in f lux of s i l t and sediment into the North Alouette River having adverse ef fects on the growth of the plants. In January and February 1980 only plant germlings were found and i t was not unt i l March that macroscopic plants were seen again. The germlings were s im i la r in s ize to those co l lected during the f a l l . Filamentous green algae (CJedogoniales, U lot r i cha les) and blue-green algae (Osc i l l a to r i a l e s ) were intermixed on the rocks with the Au. sp. In March and Apr i l small plants were mixed with blue-green (Chamae-siphonales, Osc i l l a t o r i a l e s ) and filamentous green algae (Klebsormidiales, Oedogoniales, U lo t r i cha les ) , while in May the population became dominant in the shaded areas and many "clean" (non-epiphytized) macroscopic plants were found (F ig . 6). Filamentous green algae were s t i l l present Tn the r i ve r but they were mainly concentrated in the sunny areas. In the spring water temperature averaged 6.7°C and pH, ca. 5.3. A current reading taken on 18 May 1978 was 73 cm-s-^ (average of three readings, Wehr, 1979). During the winter (1979) and spring (1978-80), plants reached a maximum of 2 cm in height. They were eas i l y recognizable as pink-grey clumps on the rock surfaces and they bore many branchlets terminating with hair c e l l s and monosporangia (Figs. 6, 7). In the summer months, June through August, most of the Audouinella co l lected was badly contaminated with the epiphyt ic blue-green alga Chamaesiphon (F ig. 60) and diatoms. Plants that were heavi ly epiphytized 23 had notably fewer ha i r s . In August, only germlings were observed in rock scrapings. The water temperature of the r i ve r , during the summer months averaged 14.5°C and pH ca. 6.5 (Table I ) ; current 147 c n r s - 1 (Wehr 1979). In summary, the winter and spring months appeared to be the best seasons for the growth of Au. sp. in the North Alouette River. Water temperatures were colder, water current faster and the competition for l i gh t and space in the shaded areas seemed to be reduced. Nutr ient leve ls in the r i ve r were not measured. Competition for l i gh t and space i s suggested based on seasonal observations of the area. Sexually reproductive plants were not found, even during periods of act ive growth. I t should also be noted, however, that the seasonal i ty for Au. sp. appears to vary depending on the r i ve r and year in which the plant populations were studied. Following completion of th i s study, in the f a l l , 1980, macroscopic plants were found in the North Alouette River. The r i ve r temperature was 10.5°C and pH 6. ;These recordings are s im i la r to the data obtained in 1978-79 (Table I ) . Col lect ions made in Oregon and Washington (Table II) at the end of June 1978 contained "clean" macroscopic p lants . River temperatures varied from 8.5 to 16.5°C and the alga was epiphyt ic on another freshwater red a lga, Lemanea or submerged mosses (Table I I ) . Plants were occasional ly found in shaded areas but not always (Table I I ) . Macroscopic, non-epiphytized plants were also found in September in a r i ve r near Bamfield, B. C. (Table I I ) . Large clumps grew near the r i ve r bank on rocks in a shaded area. Audouinella was the dominant alga in the area. 24 B. CYTOLOGICAL OBSERVATIONS OF FIELD AND CULTURED MATERIAL U l t r as t ruc tu ra l l y Audouinella sp. had typ ica l florideophycean features (Dodge 1973). The alga was characterized by a number of in teres t -ing morphological and u l t ras t ruc tura l features. The d i f f i c u l t y in obtaining good th in sections was due, in part , to the extremely th ick ce l l wall (F ig. 10) which appeared to be f i b r i l l a r in nature (F ig . 56). Occasional ly, a th in electron-dense outer ce l l wall layer was also observed (F ig . 57). Each ce l l contained one chloroplast which varied s i gn i f i c an t l y in i t s morphology. Occasional ly i t assumed a sp i ra l form, but more often i t was per iphera l ly located in the ce l l with lobes extending towards the centre (F igs. 9-14). Thylakoids within the chloroplast were in a typ ica l para l l e l arrangement with one or more enc i rc l ing the others (Figs. 10, 12, 15, 16). In some electron micrographs, phycobilisomes were present on the surface of the thylakoid membranes (Figs. 15). P lastoglobul i varied in shape from spherical (F ig. 15) to d i s c - l i k e structures (F ig . 11). A number of e lectron translucent DNA areas were evident in the chloroplast (F ig . 14). With the aid of Hoffmann opt i cs , large vacuolar regions were seen within each ce l l (F ig . 8) . These vacuoles were also observed in electron micrographs and contained membrane material (F ig . 11). Electron micro-graphs also revealed other ce l l features. Floridean starch was accumulated in large amounts in the ce l l cytoplasm (F igs. 10, 13, 14). Golgi bodies were always associated with mitochondria (Figs. 17-19) and often a complex of several golgi bodies and mitochondria was observed (F ig. 17). Mitochondria had tubular somewhat i r regu lar c r i s tae and varied in shape from spherical (F igs. 17, 18) to elongate (F ig. 19). The nucleus (F ig . 25 14) containing a prominent nucleolus (F ig . 58) was occasional ly surrounded by endoplasmic reticulum (F ig . 59). In some electron micrographs, endoplasmic reticulum was present along the ce l l periphery adjacent to the plasma membrane (F ig . 20). As in most red algae, p i t plugs were present between adjoining ce l l s (F ig . 26). The p i t plugs were dumb-bell in shape and bound on each end by a two layered plug cap (Figs. 53, 54). Convolutions of d i la ted endoplasmic reticulum surrounded the plug area (F ig. 55). Large l i p i d - l i k e bodies were very common in natural and culture co l l ec t i ons . L ight microscopy revealed prominent ves icu lar bodies in l i v i ng (F ig. 22) and haematoxylin stained material (F igs. 23-26). These bodies were shown to be l i p i d s , using the sta in Sudan IV (Jensen 1962). In most of the material observed the l i p i d bodies appeared to aggregate at the p i t plugs (F ig . 26) and sometimes seemed in a divided state (F ig . 25). Electron micrographs revealed small and large dense l i p i d bodies between the starch granules in the cytoplasm (Figs. 10, 21). Monosporangia and hair c e l l s were produced terminal ly and l a t e r a l l y on branches and branchlet c e l l s (F igs. 27, 44). Monosporangia were of common occurrence (Figs. 30-33), but occas ional ly bisporangia were observed (F ig . 28). Monosporangia ranged in s ize between 11 and 19 ym in length and 8 and 11 ym in diameter with no dif ference between f i e l d and cultured material (Table V). Regeneration of the monosporangia was common, development occurring l a t e r a l l y in a dichotomous-1ike pattern (Figs. 30-32, 41-43). The ce l l subtending the empty monosporangium elongated into the empty sporangium, the nucleus divided and a new monospore developed (F ig . 30). Several successive monosporangia developed (F ig . 42) and as many as s ix old monosporangia! wall layers were present 26 (Fig. 32). Often after several regenerations a new branch cel l extended into the empty monosporangium which in turn divided to produce a new monosporangium above i t (Figs. 29, 31, 32). Monospores were released through an opening at the top of the mono-sporangium (Figs. 23, 33, 41) and often a piece of wall layer remained in the centre of the empty sporangium (Figs. 31, 32). Prior to release the monospores became granular in appearance and when released they assumed a spherical shape (Fig. 34). After release of the monospore the pit plug separating the monosporangium from its subtending cel l remained intact (Fig. 43). In culture, monospores never settled to the bottom of the petri dish but germinated whilst attached to the free floating mother plant. Prior to in i t ia t ion of a germ tube, the spore became oval in shape (Figs. 35, 36) and monopolar germination occurred (Fig. 37). A rhizoidal-type of filament was formed (Figs. 38, 39) and the cytoplasm moved into the developing filament before a cross-wall was formed, leaving an empty spore behind (Fig. 40). The new filament contained an abundance of floridean starch and chloroplasts. New filaments were pale pink in colour and became easily contaminated with bacteria in culture. Attempts to trigger monospore release in culture were unsuccessful. The thin-walled hair ce l ls were colourless (Figs. 27, 44) and varied in length from 19 to 243 ym. The absence of chlorophyll in the hair ce l ls was demonstrated by fluorescence microscopy (Figs. 91, 92). A cross-wall between a hair cel l and i ts subtending cel l was always observed and i t was concluded that i t developed early in the production of a hair c e l l . As the hair ce l l grew outward the cytoplasm became concentrated at the t ip of the cel l (Fig. 45). A pit plug occurred between each hair cel l and i ts 27 subtending ce l l (F ig . 46). The f ine structure of the hair c e l l s was characterized by the presence of a nucleus and lack of chloroplasts or any proplast id type of organelle (F ig . 50). However, many mitochondria and associated golgi bodies were-present (F igs. 47-52). The golgi bodies appeared to be very act ive in the production of ves ic les (F igs. 48, 49, 51, 52) and in many of the c e l l s a substantial amount of endoplasmic reticulum was present (F ig . 49). A few of the golgi ves ic les contained an electron-opaque substance which has not been iden t i f i ed chemically (F ig . 52, arrow). Cultured material displayed some morphological var iat ions not observed in plants from the f i e l d . Often some of the fi laments became rh izo ida l (F ig . 62), with lengths ranging between 38 and 46 ym (+ 3.8) and diameters between 6 and 7 ym (+ 0.5). Ce l l s of the erect axes often formed chains of short bulbous c e l l s (F ig . 61) with s izes ranging from 19 to 27 ym in length (.+ 3.7) and 8 to 9 ym in diameter (+0 . 6 ) . In general, the ce l l s of the erect axes did not reach the maximum length of those co l lected in the f i e l d . Irregularly-shaped t i p c e l l s occas ional ly developed (F ig . 63). New apical c e l l s commonly grow by pushing through dead c e l l s (F ig . 64-66) and remnants of the dead ce l l s were s t i l l evident even af ter the new c e l l s had developed completely (Figs. 64, 65). C. CHROMOSOME COUNTS AND CELL DIVISION The aceto-iron-haematoxylin-chlor.al hydrate so lut ion read i l y stained the chromatin in the nuc le i . However, chromosome counts were d i f f i c u l t to obtain because ce l l d i v i s i on was not synchronous and i t was l imi ted to the growing t i p s , developing l a te ra l branches and monosporangia. When 28 d is t inguishable, chromosomes were very small and not evenly spread. Condensed chromosomes were found occasional ly at the t i p of hair c e l l s . There were four chromosomes, two very small ones ca. 0.3 um and two larger ones ca. 0.4 ym. During la te prophase eight chromatids were v i s i b l e (F ig . 67). Several other morphological features of c e l l d i v i s i on were noted. Interphase nuclei in monosporangial branch c e l l s d i f fered in appearance from those in c e l l s of the main axes. The nuclei consisted mainly of densely sta in ing chromatin surrounded by a small amount of nucleoplasm and in some 3 to 4 d i s t i n c t masses of chromatin could be counted (F ig . 68). Interphase nuclei in c e l l s of the main axes were not always v i s i b l e but when evident (usual ly in the t i p ce l l s ) they contained a d i s t i n c t nucleolus and chromatin surrounded by a c lear area of nucleoplasm (Figs. 69, 70). Pr ior to d i v i s i on , the apical ce l l of the main axes often elongated leaving the nucleus in a central "bulge" (F igs. 69, 71). During la te interphase, chromatin began to condense in associat ion with the nuclear envelope (Figs. 71, 72). At metaphase the chromatin formed dark sta in ing disc-shaped metaphase plates in several or ientat ions. The plates were e i ther p a r a l l e l , perpendicular (F ig . 73) or oblique to the long i tu-dinal axis of the c e l l . Metaphase plates were also found in hair c e l l s (F ig . 74). Chromatids separated as two masses and moved towards the poles in horse-shoe configurations (F igs. 75, 76). Cytokinesis occurred af ter the two new nuclei were in the interphase condit ion (F igs. 77, 78). Occasional ly, two interphase nuclei were observed in the ce l l s subtending monosporangia (F ig . 79). 29 D. PRELIMINARY STUDIES ON THE GROWTH OF AU. SP. AT DIFFERENT LIGHT INTENSITIES Growth in cul ture was studied using ca lcof luor dye as an ind icator . In general, plant cross-wal ls stained darker with the dye than the remainder of the c e l l (F ig . 80). New developing t i p c e l l s of the main axes and branches were eas i l y d ist inguishable (Figs. 81, 82, 85, 86) and ce l l elongation was also noted (Figs. 83, 84). Elongation occurred by the production of new ce l l wall material only. I f the or ig ina l ( label led) ce l l wall had contributed to the area of elongation the labe l led part would have become dif fused through the ent i re ce l l wa l l . This did not occur (Figs. 83, 84). New ce l l s tended to be l i gh te r in colour not only when observed with blue l i gh t (F ig . 86, 88, 90), but also when seen with regular white l i gh t (F igs. 85, 87, 89). The monosporangial wall exposed to the dye did not absorb i t well so that i t was not possible to d i f f e ren t i a te the monosporangia which developed l a te r (F igs. 91, 92). Under d i f fe rent l i gh t i n t ens i t i e s , plants grew s i gn i f i c an t l y faster (probab i l i ty level p<0.05) at the higher l i gh t in tens i ty (A) than at the lower l i gh t in tens i ty (B), (F ig. 93). The diameters of new t i p ce l l s and the eel 1 s iirmediately below the t i p ranged between 8 and 9 ym at both l i gh t i n tens i t i e s . However, c e l l lengths for both these c e l l s were s i g n i f i -cant ly larger at the higher l i gh t in tens i ty (A), ranging from 20 to 65 ym. At the lower l i g h t in tens i ty c e l l lengths ranged from 15 to 50 ym (Figs. 94, 95). The ce l l lengths for the higher l i gh t in tens i ty were comparable to the c e l l s izes recorded for f i e l d co l lected material (Table IV). Samples of 'Au. sp. labe l led with ca lcof luor dye and then placed in the dark showed no new growth af ter 3 months. The plants were s t i l l a l i ve 30 and r e i n i t i a t ed the i r growth when returned to normal culture condit ions. E. SPECIES DESCRIPTION The fol lowing descr ipt ion of Audouinella sp. was derived from the present study: Uniser iate f i laments in t u f t s , reaching a maximum of 2 cm in height; plants composed of an erect and prostrate system; the basal system made up of many branched intertwining f i laments; the erect system wall developed and much branched; c e l l s of main axis c y l i n d r i c a l , lengths range from 27-65 ym; diameters range from 9-19 ym; ce l l lengths increase under higher l i gh t i n t ens i t i e s ; branch ce l l lengths 38-50 ym, diameters 8-11 ym; chloroplasts one per c e l l , sp i ra l shaped but more often i r r egu la r l y band shaped, par ieta l in the c e l l , thylakoids s ingle in a para l l e l arrangement with one to three peripheral thylakoids, pyrenoids absent; nucleus one per ce l l with a prominent nucleolus, chromosomes n=4, two ca. 0.4 ym, two 0.3 ym; many long and short l a te ra l branches along the main ax i s , denser towards the base; short l a te ra l branches often terminating in hair c e l l s and/or monosporangia; monosporangia lengths 11-19 ym, diameters 8-11 ym; hair c e l l s mainly on la te ra l branches, occas ional ly terminal on the main ax i s , lengths 16-243 ym, diameters 2-6 ym tapering towards the t i p ; sexual reproduction unknown; plants attached to rocks, moss or other freshwater red algae in fastrunning creeks and streams mostly in shaded areas; abundant in the winter and spr ing; germlings common in rock scrapings during the summer and f a l l . 31 DISCUSSION A. TAXONOMY The Audouinella sp. in the present invest igat ion was o r i g i na l l y i den t i f i ed as Au. violacea (Stein and Borden 1979), although i t should have been assigned the older epithet A L L hermanni (Israelson 1942). In order to confirm the i den t i f i c a t i on , the species descr ipt ion derived from th i s study was compared to descr ipt ions of 24 freshwater species in the Acrochaetiaceae (Appendix Table I ) . Nine of the species l i s t e d : Chantransia beardslei Wolle; C^ . hercynica Kutz.; C^ . compacta Ra l fs ; C^ . dalmatica Ki itz.; C. serpens Israelson; C. subt i l i s Mobius; C_. l e i b l e i n i i Kutz.; C^ . ramellosa Kiitz.; and Balbiania meiospora Skuja have descr ipt ions with so few charac ter i s t i cs that they cannot be dist inguished from Audouinel!a observed in th i s study. Seven of the freshwater species have been reported to have more than one chloroplast per c e l l : C^ . cy l i nd r i ca Jao; C^ . tene l la Skuja; C.. eugenea Skuja; Au. glomerata Jao; Au^ . s inensis Jao; Acrochaetium godwardense Pate l ; and Rhodochorton venezuelensis D'LaCoste and Ganesan. However the number of chloroplasts per ce l l can eas i l y be mistaken in A I K species. A s ingle lobed chloroplast viewed through the l i gh t microscope can appear to be more than one. Therefore I suspect that most of the numbers provided for the above species are questionable with the exception of those for R_. venezuelensis which appear sat i s fac tory (D'LaCoste and Ganesan 1972). Based on vegetative charac ter i s t i cs alone, A L L sp. could be any one of the above asexual species as well as the remaining seven asexual species which have been described in more de t a i l : A L L lanosa Jao; C^ . macrospora 32 Wood; C^ . pygmaea Ku'tz.; Au_. chalybea Bory; Ac. indica Raikwar; Ac. sarmaii Kahn, and Ac. amahatanum Kumano. However, most of these species do not appear to be unique and require further study. Sexual reproduction has been reported in two freshwater species: Audouinella violacea [- C.. boweri Murray and Barton (Drew 1936)] and Rhodochorton investiens (Lenorm.) Swale and Belcher [= Balbiania investiens (Lenorm) S i rodot] . In concluding the i r study Swale and Belcher (1963) remarked that " i t appears that there is no fundamental di f ference between Balbiania and members of the Rhodochorton-Acrochaetium complex, such as Rhodochorton violaceum (K'utz.) Drew (= Au. v io lacea) . In agreement with Drew (.1928) they used the generic name Rhodochorton and named the i r plant R. invest iens. I bel ieve that th i s plant should have been synonymized with R_. violaceum (for complete descr ipt ions see Appendix Table I ) . Sexual reproduction was not observed in the Au. sp. studied here and unt i l i t i s found the alga should not be ca l led Au. hermanni (= Au. v io lacea) . In th i s study Aju. sp. was not compared to the many type descr ipt ions of the marine members of the Acrochaetiaceae. Using descr ipt ions provided in current l i t e r a tu re (Woe!kerling 1971; Dixon and Irvine 1977) f i ve marine species were found to be s im i la r in only a few aspects- These include ' Au. eff lorescens ( J . Ag.) Papenfuss, Au. pectinatum (Kyl in) Hamel, Au_. thuret t i (Bornet) Woel kerl ing, Au^ . corymb i f era (Thuret) Dixon and Au. purpurea (L ight f . ) Woelkerl ing. A l l the species l i s t ed have both erect and basal systems; the f i r s t four species reproduce asexually by monospores and the c e l l s contain one par ieta l ch loroplast , varying in shape from i r regu lar and band-l ike to sp i ra l and r ibbon- l i ke (note: Au. eff lorescens can have more than one ch lorop las t ) . These species are s t r i c t l y marine in habitat except for Au. purpurea which i s reported as 33 growing t e r r e s t r i a l l y and in i n te r t i da l regions where freshwater runoff i s predominant (Rosenvinge 1900; Knaggs 1967b). B. MORPHOLOGICAL PLASTICITY The current study showed that the number of chloroplasts per ce l l and the general habit of the plant are the only stable vegetative character is-t i c s of Au. sp. There was always one chloroplast per ce l l and both erect and basal systems were present even in the germ!ing state. The remainder of the morphological features general ly used in taxonomic descr ipt ions were var iable and were not included in the preceding d iscuss ion. These features were: the length and diameter of hair c e l l s , c e l l s of the main axes and branch c e l l s ; chloroplast type which varied from sp i ra l in the apical c e l l s to more band-shaped in the older c e l l s ; and the basal system composed of many intertwin ing fi laments which varied depending on the s ize of the "clumps" that were co l lected and whether or not they were teased apart. These features could be used to d i f f e ren t i a te species only i f allowances are made for morphological p l a s t i c i t y . A l l the studies on morphological p l a s t i c i t y in the Acrochaetiaceae have been done exc lus ive ly on marine members. West (1968, 1971) noted in Au. pectinatum and Acrochaetium proskaueri that during ontogeny there was much v a r i a b i l i t y in chloroplast morphology, o r ig in and frequency of sporangia, branches and hair c e l l s . He concluded that these character is-t i c s were unre l iab le as taxonomic c r i t e r i a . While studying temperature effects on various species of Audouinella Garbary (1979b) also found that branching was var iab le . In addit ion he reported that sporangial s i ze , other ce l l dimensions, and the thickness of the ce l l wall were extremely 34 var iab le. Stegenga and various co-workers (Stegenga and Borsje 1976, 1977; Stegenga and Vroman 1976; Stegenga and Mulder 1979) in the i r studies of the l i f e h i s to r ies of Ac. polyblastum (Rosenv.) Borg., Ac. hallandicum (Kyl in) Hamel, Ac. dasyae Co l l i n s , Ac. densum (Drew) Papenfuss and Au. microscopica (Nag.) Woelkerling found that branch frequency and pattern, presence of hair c e l l s , morphology of the basal system, number of erect axes and the number of pyrenoids were var iab le . But, unl ike West (1968, 1971) and Garbary (1979b), they noted that chloroplast type, ce l l diameter and to some extent the monosporangial dimensions were stable charac te r i s t i c s . The general plant s t ructure, type of spore germination and carposporophyte were also considered stable charac te r i s t i c s . The s t a b i l i t y of the general plant structure in Au_. sp. agrees with the reports by Stegenga and co-workers. Those features which West and Garbary considered var iable were also var iable in A I L sp. (note: the thickness of the ce l l wall was not measured in Au. sp . ) . C. SEASONALITY In general Au_. sp. was most abundant in the winter and spr ing. Drew (1935) also noted that R. violaceum was abundant in the winter and spr ing. D i l l a rd (.1966) found in North Caro l ina, that Au. violacea was dominant only when water temperatures were less than 15°C. The North Alouette River rare ly exceeded 15°C and the disappearance of Au. sp. in macro-scopic form did not appear to be re lated to the temperature. The seasonal i ty of Au. sp. appeared to be very spec i f i c to the r i ve r or stream and the year in which i t was co l l ec ted . Wehr (1979) hypothe-35 sized that the change in species composition in the Alouette River water-shed could possibly be due, in part, to per iodic disturbances, such as nutr ient pulses and f loods. He also suggested that the d i s t r i bu t i on of red algae was shade l im i ted . A better understanding of the seasonal i ty of Au. sp. can be achieved by a long term ecological study. D. CYTOLOGY In the current study of Au. sp. the f ine structure was constant throughout the year and in a l l the samples that were processed for electron microscopy. Several cyto logica l features of interest were observed. Large l i p i d bodies were evident in many of the c e l l s in f i e l d and cultured mater ia l , often located close to the p i t plug. Pearlmutter and Cole (1980) reported the same structures in a clone of f*. pur- pureum. Using cytochemical tests they showed that these bodies were l i p i d s and that they were formed i n i t i a l l y in the c e l l cytoplasm. They also noted that the l i p i d s aggregated at the p i t plugs and were in close associat ion with the endoplasmic ret iculum. Pueschel (1977) found large l i p i d bodies surrounded by an apparent reticulum of b i furcat ing membranes in the outer cortex of Palmaria  palmata (L.) 0. Kuntze. These l i p i d bodies were s im i la r to the "corps en cer ise" located in the co r t i ca l c e l l s of several Laurencia spp. (Bodard 1968; Feldmann and Feldmann 1950). A membrane surrounding the l i p i d bodies in AIJ . sp. was not observed. Young et a l . (1980) showed that the "corps en cer ise" in Laurencia snyderae Dawson contained the brominated natural product e-synderol, a halogenated sesquiterpenoid. The l i p i d bodies of Au_. sp. in l i gh t micrographs look s im i la r to those in 36 the t r i chob las ts and co r t i ca l c e l l s of L_. snyderae but further work on the i r contents i s merited. The function of the l i p i d bodies in Au. spp. i s unknown. According to some electron micrographs of s ingle sections of Au. sp. i t may appear that there was more than one chloroplast per c e l l . However i t was c l ea r l y seen as a s ingle unit in l i g h t microscope observations. The chloroplast was sp i ra l to i r regu la r band-shaped and lacked pyrenoids. Hara and Chihara (1973) claimed that a l l freshwater red algae contained chloroplasts of the Polysiphonia or Batrachospermum types, lacking pyrenoids. These types in fe r that there were many d isco id par ieta l chloroplasts per c e l l ; a claim which cannot be applied to a l l freshwater red algae (e.g. ALL sp. , Au. hermanni, Chroodactylon ramosum (Thwaites) Hansg.) (Sheath and Hymes 1980). P i t plugs of Au^ . sp. were dumb-bell shaped and bound by a two layered plug cap. A l l members of the Acrochaetiaceae that have been observed u l t r a s t ruc tu ra l l y contained p i t plugs s im i la r to these (Lee 1971; Pueschel and Cole 1981 pers. comm.). This type of p i t plug is s imi la r to the Nemalion-type described by Feldmann et a l . (1977). Di lated endoplasmic reticulum in the area of the p i t plug was common in Au. sp. and other species of red algae ( e .g . , Feldmann et a l . 1977; Aghajanian and Hommer-sand 1978). E. HAIR CELLS The most in terest ing feature observed in Au. sp. was the un i ce l l u l a r hair c e l l . The u l t rast ructure of these c e l l s has not been described before. Hair c e l l s appear to be t o t a l l y lacking in members of the 37 Bangiophyceae, while in the Florideophyceae they have never been detected in members of the Gigartinaceae and Phyllophoraceae (Gigart inales) or in the Delesseriaceae, Dasyaceae and Rhodomelaceae (Ceramiales) (Dixon 1973). In his survey of the Florideophyceae, Rosenvinge (1911) noted that un i ce l l u l a r hair c e l l s were the most common. These hair c e l l s were usual ly terminal on branches or c e l l s of the main axes. They developed as out-growths of peripheral c e l l s , contained no chloroplasts (except for Plumaria elegans (Bonnem.) Schm.) and were separated by a transverse wall as a small c e l l , ear ly in development. He also observed that the young hair c e l l s contained a nucleus and were f i l l e d with dense protoplasm. As the c e l l lengthened i t became vacuolate, forc ing the nucleus to the t i p surrounded by a th in layer of protoplasm. West (.1971) noted the same type of development of un i ce l l u l a r hair c e l l s in Ac. proskaueri. However, he also found short l a te ra l projections along the axis of some of the hair c e l l s and he did not detect any chloroplasts or a nucleus within the c e l l s . Rosenvinge (1911), West (1971) and Akatsuka (1978 Gelidiaceae ) reported that hair c e l l s did not always develop but usual ly occurred when growth was act ive . Hair c e l l s were shor t - l i ved; they developed ear ly and died long before plant growth stopped (Rosenvinge 1911). Dixon (1973) commented that in the northern hemisphere red algal hair c e l l s were abun-dant in the spring and ear ly summer and absent in the winter. He suggested that th i s might be related to periods of act ive growth. In Au_. sp. hair c e l l s were common a l l year on large healthy plants as well as germlings. Development of the hair c e l l s followed the same pattern described by Rosenvinge (1911). The nucleus of the hair c e l l was eas i l y discernable in haematoxylin stained material and often the 38 chromatin appeared to be in a condensed state at the t i p of the c e l l s . Occasional ly metaphase plates were observed but not any other stages of mitos is . In the hair c e l l s of Call ithamnion byssoides Arnott ex Harv. in Hook (Ceramiales. ) the nucleus was observed to div ide in two (Rosenvinge 1911). I t i s d i f f i c u l t to explain why nuclear d i v i s i on occurs in the c e l l s . The function of the hair c e l l s i s s t i l l unknown. In general i t i s believed that they absorb nutr ients for the alga (Rosenvinge 1911, Dixon 1973). West (1971) showed that an increase in the number of hair c e l l s in Ac_. proskaueri was contro l led by an increase in l i g h t in tens i ty . This could perhaps be due to the increase in act ive growth of the a lga. Van den Hoek and Flinterman (1968) found that hair c e l l s in the brown alga, Sphacelaria furc igera Ku'tz. developed when the cultures were depleted of nutr ients . Ky l in (1917) stated that the hair c e l l s of Dumontia f i l i f o rm i s Grev. grew in cultures that did not contain n i t rates but did not develop in cultures to which n i t rates were added. It i s possible that the f ine structure of Au_. sp. hair c e l l s supports the hypothesis that these c e l l s serve an absorptive funct ion. The ce l l wall i s extremely th in in contrast to vegetative ce l l s and the surface area of the ce l l s is great. They contain mitochondria, endoplasmic ret iculum, a large nucleus, golgi bodies and many ves i c les . A l l of these ce l l u l a r inc lus ions are instruments which could al low absorption to occur. Further studies are s t i l l required to determine the function of these c e l l s . 39 F. MONOSPORE RELEASE AND REGENERATION In an extensive study of Ac. virgatulum (Harv.) J . Ag. monospores were shown to be released in three d i f fe rent ways; i ) an apical s l i t or tear in the monosporangium wa l l ; i i ) an apical rupture; and/or, i i i ) a l a t e r a l l y placed dehiscence (Boney 1967). Monospore and fi lament regeneration in old monosporangia appeared to be common. In ALL sp. monospores were released through an opening in the apical wall of the monosporangium. Regeneration of monosporangia, fi laments and occasional ly hair c e l l s through the monosporangia was observed. Regeneration of damaged apical c e l l s also occurred. G. CHROMOSOMES During late prophase, eight chromatids (four larger ca. 0.4 ym and four smaller ca. 0.3 ym) were counted in Audouinel!a c e l l s . These chromatids were s i gn i f i c an t l y smaller than those reported by Magne (1964) in his survey of the Rhodophyta. He noted that most chromosomes ranged from 2-4-(5) ym in s i ze . Three d i f fe rent s izes of chromosomes were found in the spermatia of 15 species of Porphyra from the west coast of North America (Mumford and Cole 1977). The shorter chromosomes ranged in s ize from 0.5 to 1.0 ym and are comparable to those of A I L sp. The s ize and shape of the chromosomes in ALL sp. resemble the minute chromosomes in mosses (Ramsey 1966, 1974). Chromosome numbers in the Acrochaetiaceae have not been studied extensively, probably because ce l l d i v i s i on i s d i f f i c u l t to synchronize and the chromosomes are so smal l . Magne (1964) reported elongate 40 chromosomes in Au. f l o r i d u l a , each ce l l containing ca. 20 chromosomes (n or 2n). Woelkerling (1970) found chromosome numbers of n=5 and 2n=10 in c e l l s of Ac.botryocarpum. West (1970b) counted between 12 and 14 chromosomes in the prophase nuclei of in terca lary vegetative ce l l s of R. concrescens. In Au_. sp. 8 chromatids were counted in late prophase stage and i t i s l i k e l y that West (1970b) was also observing chromatids. Hence, his count was probably n=6 or 7. In the red algae the majority of the Florideophyceae have high chromosome numbers. Dixon (1966) recorded three ranges of counts: 30-32; 59-65; and 87-98. Ten species of algae in the Florideophyceae have chromosome counts of 4 or 5, one species in the Acrochaetiaceae, three species in the Gel idiaceae, f i ve species in the Gigart inales and one species in the Chaetangiaceae (Dixon 1966; Moore 1973, 1977). In the Bangiophyceae chromosome counts range between 2 and 5, also s im i la r to Au. sp. ( e .g . , i n Mumford and Cole 1977; Yabu and Tokida 1963; Kito 1978). I t has been observed in the red algae that the aggregation of chromosomes into clumps along the metaphase plate is common, making i t impossible to determine numbers at th i s stage (Dixon 1966; Mumford and Cole 1977). Dixon also stated that during anaphase and telophase the movement of chromosomes to the poles i s very rapid and the two sets of chromosomes separate as two masses. The chromosomes of Au. sp. also clumped at the metaphase plate and moved to the poles as two masses. The anaphase condit ion was easi ly, detectable because the chromosomes were associated in a charac te r i s t i c horse-shoe type of conf igurat ion. This has also been noted in Bangia spp. (Cole pers. comm.). 41 H. GROWTH USING CALCOFLUOR DYE Calcof luor white dye has been used as an nontoxic label in studies of algal growth (Cole 1964; Waaland and Waaland 1975). I t has also been used as a v i t a l s ta in to l o ca l i se ce l lu lose and ch i t i n (Haigler et a l . 1980). Cole (1964) showed that ac t i ve ly growing t ips of the gametophytes of some members of the Laminariales (Phaeophyta) f luoresced br ight ly when labe l led with dye but the reproductive structures in general absorbed the dye weakly. In Aud. sp. the monosporangia also absorbed the dye weakly, making i t impossible to t e l l i f new growth had occurred. Waaland and Waaland (.1975) showed that elongation in f i ve species of red algae was confined to the narrow bands at each end of the la te ra l wal ls of growing interca lary c e l l s . In contrast, a l l growth of Aud. sp. was apical and elongation was confined to apical c e l l s only. Elongation occurred by the production of new ce l l wall material at the growing t i p . I . CONCLUSION According to the present study several features of the freshwater Acrochaetiaceae merit further invest igat ion. Hair c e l l s are pa r t i cu l a r l y abundant on Au_. sp. I t would be of value to estab l ish the function of these c e l l s and to corre late th is with the u l t ras t ruc ture . A determina-t ion of the function and frequency of l i p i d bodies in the Acrochaetiaceae would be of in teres t ; an analysis of the contents would be requ is i te . 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J_. Bot. suppl. ser ies 1 : 1 - 9 1 . 1 9 7 3 . The morphology and systematics of the Audouinella complex (Acrochaetiaceae, Rhodophyta) in northeastern United States. Rhodora 7 5 : 5 2 9 - 6 2 1 . Yabu, H. and Tokida, J . 1 9 6 3 . Mi tos is in Porphyra. Bu l l . Fac. F i s h . , Hokkaido Univ. 1 4 : 1 3 1 - 6 . Young, D. N . , Howard, B. M. and Fen ica l , W. 1 9 8 0 . Subcel lu lar l o c a l i z a -t ion of brominated secondary metabolites in the red alga Laurencia snyderae. LL Phycol. 1 6 : 1 8 2 - 5 . Wolle, F. 1 8 8 7 . Fresh-water Algae of the United States; Desmids of the  United States. Bethlehem, PA. 52 FIGURE LEGENDS: A l l f igures are of Audouinella sp. from the North Alouette River unless otherwise spec i f i ed . The micrographs are from cultured material unless otherwise stated. The fol lowing abbreviations w i l l be used; 3:1 W = alga f ixed in Carnoy's 3:1 a lcoho l :acet ic ac id and stained with Wittman's aceto-iron-haematoxylin-chlorohydrate so lut ion; Hoffmann = Hoffmann modulation contrast system; Met. = fi laments f ixed in methacrylate. 53 F ig . 1. L ight micrograph of plant germlings; co l lected 15 August 1979. X 400. Figs. 2-4. Met. stained with PAS/AN. F ig . 2. Note erect and basal c e l l s . X 500. F ig . 3. Detai l of a cross-sect ion of basal c e l l s . Note d i f ferent shapes of c e l l s . X 4,200. F ig . 4. Section showing the filamentous condit ion of the basal c e l l s (arrow). X 2,300. F ig . 5. >||ew branch developing fol lowing nuclear d i v i s i on . Filament f ixed and stained in 3:1V!. X 3,000. 53 A 54 Fig. 6. Light micrograph showing the erect axes containing many hair c e l l s and monosporangia on the tips of branches; collected 21 May 1979. X 300. Figs. 7-9. Hoffmann. Fig. 7. Detail of the erect axes showing various stages of development of the monosporangia (arrows). X 4,000. Fig. 8. Detail of the erect axes. Note vacuolate condition of the c e l l s (arrows); collected 11 January 1979. X 1,500. Fig. 9. Light micrograph of the c e l l chloroplast (arrows). The chloroplast i s peripheral and somewhat l.obed; collected 11 January 1.979. X 3,200. 55 Figs. 10-12. . The f ine structure of Au. sp. ; cross sections of c e l l s . F ig . 10. Cel l with peripheral chloroplast (C), th ick ce l l wall (CW), f lor idean starch (S) deposited in the centre of the ce l l and electron dense l i p i d deposits (arrow); co l lected and f ixed 9 May 1979. X 14,400. F ig . 11. Peripheral chloroplast (C) containing p lasto-globul i (arrow) and note the vacuolate (V) area within the c e l l ; co l lected and f ixed 9 May 1979. X 17,200. F ig . 12. Mitochondria (M) and golgi bodies (double arrow) evident with chloroplast containing three peripheral thylakoids (arrow) enc i rc l ing the remaining thylakoids; co l lected 23 June 1978 from Neskoun Creek, OR. X 13,100. 56 Figs. 13-16. Plant was co l lected and f ixed 9 May 1979. F ig . 13. Section of f i lament showing the c e l l wa l l , per iphera l ly lobed chloroplast and f lor idean starch deposits (S). X 6,000. F ig . 14. Cel l cross-sect ion: note the nucelus (N), f lor idean starch (S), and chloroplast (C) con-ta in ing electron translucent DNA areas (arrows) X 14,000. F ig . 15. Detai l of chloroplast showing p lastoglobul i (electron dense), one peripheral thylakoid and phycobilisomes (arrows) on the surface of the thylakoids. X 53,600. F ig . 16. Detai l of the chloroplast (C) with one s ingle peripheral thylakoid (arrow). X 35,000. 57 Figs. 17-18. Detai l of mitochondria (M) and associated golgi bodies (G); ER = endoplasmic ret iculum; co l lected 23 June 1978 from Neskoun Creek, OR. F ig . 17 X 31,800; F ig . 18 X 39,400. F ig . 19. Elongated mitochondria (M) and the associated golgi body (G); co l lected 9 May 1979. X 27,600. F ig . 20. Detai l of the ce l l showing the associat ion of the endoplasmic reticulum (ER) with the plasma membrane: note the electron translucent DNA area (double arrow) within the chloroplast (C). X 30,900. F ig . 21. Portion of a ce l l with electron-dense l i p i d deposit in the ce l l cytoplasm (arrow). X24,000. 58 Figs. 22-26. Light micrographs showing the deposit of large l i p i d bodies (LB) wi th in the c e l l s of the erect axes. F ig . 22. Note the ves icu lar appearance of the l i p i d bodies (LB), Hoffmann, co l lected 11 January 1979. X 3,400. Figs. 23-26. Sections f ixed and stained 3:1 W. F ig . 23. L ip id bodies (LB) deposited in many ce l l s of the fi laments Hoffmann; co l lected 1 September 1979 near Bamfield, B. C. X 3,300. F ig . 24. The l i p i d bodies are prominent within the ce l l s (arrows). X 1,700. F ig . 25. L ip id body possibly in a divided state (arrow). The l i p i d bodies appear to be concentrated near the p i t plugs. X 2,600. F ig . 26. In th i s micrograph the l i p i d bodies are somewhat granular in appearance (c lear arrows) and tend to be concentrated at the p i t plugs (P). Hoffmann. X 2,600. 59 F igs. 27-31. Light micrographs of monosporangia and bispo-rangia. F ig . 27. Branch containing monosporangia (M) and a hair c e l l (H), phase contrast, co l lected 21 May 1979. X 1,200. F ig . 28 Bisporangium (arrow) adjacent to monosporangium (M); co l lected 15 February 1979. X 4,000. F ig . 29-31. Ce l l s f ixed and stained in 3:1 W. F ig . 29. Third regeneration of a monosporangium: note the old ce l l wall layers l e f t behind (arrows). X 4,600. F ig . 30. Regenerating monosporangium (arrow): note the wall layers remaining in the monosporangium and the ce l l below i t . X 4,000. F ig . 31. Note the wall layers remaining in the ce l l below the empty monosporangium (c lear arrow) and the piece of c e l l wall in the centre of an empty monosporangium (so l id arrow). X 3,700. 60 F ig . 32. Light micrograph showing empty monosporangia, a newly developed monospore (M) and the s ix remaining wall layers of the ce l l below i t , 3:1 W. X 3,600. F ig . 33. Opening at the t i p of the monosporangium where the monospores escape (arrow), co l lected 21 May 1979. X 1,700. F igs. 34-40. Germination of the monospores. F ig . 34. Monospore jus t a f ter release from a monosporan-gium. The ce l l i s granular in appearance and spher i ca l , co l lected 25 January 1980. X 2,500. F ig . 35-38. Ce l l s f ixed and stained in 3:1 W. F ig . 35,36. Monospores assuming an oval shape upon germination. F ig . 35 X 3,700; F ig . 36 X 3,400. F ig . 37. A rh izo ida l - type of f i lament emerges. X 3,900. F ig . 38. Cytoplasm (arrows) moves from the spore into the germ tube. X 3,200. F igs. 39,40. The empty monospore (arrow) cut o f f from the elongated germ tube by a ce l l wa l l . F ig . 39 X 350; F ig . 40 X 3,000. 61 F ig . 41. Fine structure of branch ce l l s terminating in monosporangia: note blue-green alga growing ep iphyt i ca l l y with in an old monosporangial c e l l wall (arrow); co l lected 18 May 1978. X 1,800. F igs. 42,43. Empty monosporangia; note the many wall layers (arrows F ig . 42) and the remaining p i t plugs (arrow F ig . 43); F ig . 42 co l lected 18 May 1978. X 9,600; F ig . 43 co l lected 9 May 1979. X 17,700. 62 Figs. 44-46. Light micrographs of hair c e l l s . F ig . 44. Hair c e l l s CH) of various lengths; phase contrast; co l lected 21 May 1979. X 400. F ig . 45. Detai l of a hair c e l l showing concentration of the ce l l cytoplasm at the t i p of the hair ce l l (arrow); phase contrast; co l lected 21 May 1979. X 1,700. F ig . 46. Hair ce l l f ixed and stained 3:1 W to show the nucleus (N). The p i t plug can also be seen. X 4,000. 63 F ig . 47. Fine structure of a developing hair c e l l . Note the presence of mitochondria (M) and golgi bodies (G) and the lack of ch loroplasts; co l lected 9 May 1979. X 18,200. F ig . 48. Longitudinal section of hair c e l l : note the mitochondria (M) and small ves ic les (VS) within the c e l l ; co l lected 9 May 1979. X 7,000. Cross-sections of the f ine structure of hair c e l l s . Samples were co l lected 9 May 1979. Note the presence of an elaborate golgi body system (G), endoplasmic reticulum (ER) and mitochondria (M). X 34,100. Section showing a prominent nucleus in the ce l l centre. X 30,400. Detai l showing the golgi body (G) and the many ves ic les produced. Note that none of the ves ic les coalesce with the plasma membrane; M = mitochondria; N = nucleus. X 47,300. Detai l of golgi body (G). Some of the ves ic les appear to contain an electron-dense substance (small arrow); M = mitochondria. X 56,300. 65 Figs. 53,54. Fine structure of the p i t plug and i t s two-layered plug cap (arrows); F ig . 53 co l lected 23 June 1978 Neskoun Creek. X 39,500; F ig . 54 co l lected 21 May 1979. X 64,900 respect ive ly. F ig . 55. Section showing d i la ted endoplasmic reticulum (ER) in the region of the p i t plug; co l lected 9 May 1979. X 40,000. F ig . 56. Micrograph showing the f i b r i l l a r nature of the ce l l wall (CW); co l lected 18 May 1978. X 31,000. F ig . 57. Electron-dense wall material (arrow) found occasional ly at the periphery of the ce l l wa l l ; co l lected 9 May 1979. X 24,000. 66 F ig . 58. Longitudinal sect ion of the ce l l nucleus CN) containing a prominent nucleolus (NU); co l lected 23 June 1978, Neskoun Creek, OR. X 39,200. F ig . 59. Micrograph showing the endoplasmic reticulum (arrows) associated with the nuclear membrane; co l lected 9 May 1979. X 21,900. F ig . 60. The f ine structure of a blue-green alga (Chamaesiphon) (BG) epiphyt ic on Aud. sp. (AUD); co l lected 9 May 1979. X 9,600. Figs. 61-63. Observations of unusual features in cultured mater ia l . F ig . 61. Small bulbous c e l l s developing on the erect axes. X 3,600. F ig . 62. One ce l l of a rh i zo ida l -1 ike f i lament developing on an erect ax is ; Hoffmann 3:1 W. X 3,400. F ig . 63. Irregular development of the t i p c e l l s : note the abnormal cross wall (arrow); 3:1 W. X 3,100. F igs . 64-66. Regeneration of the new ce l l s developing through dead c e l l s . A l l sections were f ixed and stained in 3:1 W. Figs. 64,65. Note the remains of the dead ce l l alongside the periphery of the new ce l l s formed (arrows). X 3,200 and X 3,600 respect ive ly . F ig . 66. New developing ce l l pushing through a dead t i p ce l l (arrow). X 3,300. 68 F ig . 67-72. A l l samples were f ixed and stained in 3:1 W. F ig . 67. Eight chromatids (Cr) in a ce l l subtending a branch during prophase. Note the four larger chromatids and the four smaller ones. X 4,700. F ig . 68. Monosporangial branch c e l l s containing nuclei with p a r t i a l l y condensed chromatin (arrows). In some of the c e l l s i t i s possible to count 3-4 condensed masses (c lear arrow). X 3,000. F ig . 69. An interphase nucleus (N) in a central 'bulge' of a t i p c e l l : note nucleoplasm around the large densely sta in ing nucelolus. X 3,300. F ig . 70. An interphase nucleus (N) of a t i p c e l l : note the nucleus i s not in a central 'bulge' but a c lear zone of nuceloplasm can be seen around the nucleolus. X 3,300. F igs. 71,72. Pre-prophase t i p c e l l s : chromatin beginning to condense along the nuclear membrane (arrow). X 2,600 and X 2,900 respect ive ly . 69 Figs. 73-79. A l l c e l l s were f ixed and stained in 3:1 W. F ig . 73. A metaphase plate perpendicular to the longitudinal axis of the ce l l (arrow). X 3,200. F ig . 74. A metaphase plate para l l e l to the longitudinal axis of a hair c e l l (arrow). X 7,700. F i g . 75,76. Anaphase; chromosomes are in a horse-shoe type of conf igurat ion (arrows). F ig . 75 X 3,300; F ig . 76 X 3,000. F ig . 77,78. Telophase; daughter nuclei separating to the poles: note commencement of cytok ines is . F ig . 77 X 3,200; F ig . 78 X 7,300. F ig . 79. A ce l l subtending a monosporangium containing two nuclei (arrows). X 4,800. 70 Figs. 80-92. A l l f igures are of cultured material that has been labe l led with ca lcof luor dye, washed and allowed to grow in fresh culture medium. Material in Figs. 80, 82, 84, 86, 88, 90 and 92 was photographed while exposed to blue l i g h t . Material in F igs. 81, 83, 85, 87, 89 and 91 was photographed with regular white l i g h t . F ig . 80. Development of new ce l l s 12 days af ter l abe l l i ng with dye. Note the f luorescing l i p i d bodies. X 1,000. Figs. 81,82. Development of new t i p ce l l s 2 days af ter l abe l l -ing with dye. X 1,200. F igs. 83,84. New t i p ce l l s 7 days af ter l abe l l i ng with dye. Note that the t i p c e l l elongated af ter i t was l abe l l ed . X 600. 71 Figs. 85,86. Newly developed branch c e l l s 7 days a f ter l abe l l i ng with dye. X 650. Figs. 87,88. Thirteen days af ter l abe l l i ng with, dye; development of new ce l l s of the main axis and branches. X 650. 72 Figs. 89,90. Thirteen days af ter l abe l l i ng with dye. Note development of short bulbous c e l l s . X 300. Figs. 91,92. Seven days af ter l abe l l i ng with dye. The monosporangia did not absorb the dye we l l . Note that the hair ce l l did not f luoresce. X 800. 73 Figs. 93-95. KEY; bar = standard deviat ion Light A Light B tkill = 6 = 35 uEin-m" 2-s 1 yEin-m"2-s~^ F ig . 93. Growth of Au. sp. at d i f fe rent l i gh t i n t ens i t i e s ; number of new ce l l s - day - 1 (10 apices counted). •73 A 30_ CELLS 20 4 DAY 7 DAY 37 / Growth of Au. sp. at d i f fe rent l i gh t i n tens i t i e s length (ym) of new apical ce l l s during growth. Growth of Au. sp. at d i f fe rent l i gh t i n tens i t i e s length (ym) of the ce l l below the apex during growth. APPENDIX + structure present; - no information provided; L = length; W = diameter; a l l c e l l s izes are in pm A. Twenty-seven descriptions of freshwater members of the Acrochaetiaceae. Habit • Basal System ' Erect System Alga i ) asexual specie! Height Chloroplast-type and of Color Plant (mm) Pyrenoids Sexual Reproduction Monosporangium and Monospores Tetrasporangium and Tetraspores Main Axis Ce l ls Habitat and References Used Chantransia beard-s le i Wo1)e~lB79. C. compacta Ralfs T851. C. cy l indr ica Oao T941. C. dalmatit T845. Minute, hemis- + pherical tuf ts or filamentous, fronds inter laced small , r i ca l short c e l l s , i r regular branches, l a t e r a l l y cohered filamentous,' stout, r i g i d , lo ts branching, opens out radiately arranged, branches alternate from upper part , erect , elongated, apical ce l l obtuse or rarely s i i g h t l y attenuated C. eugenea Skuja T934. C. hercynica Kutz. 1845. C. l e i b l e i n i i Kutz. T845 Single or in ter - + woven cushions, creeping, pseudo-Oao (1941) - parenchy-matous caespitose, hemi-spherical un iser ia tes , lo ts branching, a l ternate, opposite, short or long branches, secund, cy l indr ica l c e l l s not constricted at cross-wal ls , end c e l l s rounded f i laments, almost com-plete ly dichotomous, branches a l ternate, short , secund filaments upright and appressed rose-purple darker co lor blue-green, 2 -4 /ce l l laminate, i r regular ly sublobed at margins purple-viol et t ips sometimes green v io le t - red , spiral bond with more or less undulating margin; more than one chloro-p l a s t / c e l l ; Oao (1941) dark steel blue 1.05 violet grey-blue to v io le t brown on upper part of branch-lets , scattered, rarely opposite-shape cyl ind-ric-ovate, sessile or on one celled pedicel terminal, uni or bi lat-eral . L-13-18-, W=7-9 abundant on inside of side branches, in rows, sess i le or on short 1-2 cel led branches, monospores-upside down egg shape. 1=14-15 ; W-16-19 Starmach (1977) L-18.24; W=12-18 length two times the width .1*11.7-13.5; .U-4-7 L-5.4-7.2 ; H=3.6 length "shorter than two times width 1*28-80 ; "U- 7-10 L-7.6-12; W=3.8-4 Starmach (1977) L=45-85; W=13-25 On stones in rapid waters with Lemanea and Au. v io lacea; Wolle 1879. Raifs (1851) • epiphytic on leaves and stems of V a l l i s n e r i a spiral is in wells and streams. South China; Jao (1941). in Kerka River , Germany; Kutz. (1845). in pond on large water p lants , India. on submerged roots and rocks in mountain streams (China); Skuja (1934); Jao (1941). in streams on boulders and Lemanea f l u v i a t i l i s , Germany; Kutz. (1245). In streams, Germany; Kutz. (1845); Starmach (1977) C. chalybea (Roth) f r i e s 1825. Audouinella i r regular branches ar is ing from central c e l l s cm glome rata Jab" 1941.' . Au. s ines ls Jab 1940. Acrochaetium  amahatanuTi Kumano 1978. united into pseu-doparenchymatous appearance, ce l ls s l i g h t l y tumid, 2 times longer than broad of creeping base, i r re -gular and numerous branches, apical ce l l of branch obtuse, narrower than lower eel Is thal lus minute short c e l l s , l a t - erect filamentous numer-eral branches, ous, densely pulvinate c e l l s more or less with few branches or un-tumid (swollen) branched false hairs? 1.5-2 times longer present on end of f i l a -than wide thal lus densely pu lv inate , widely expanded thal lus densely caespitose or 'pulvinate ments patent, apical c e l l s s l i g h t l y attenuated with obtuse apex branches elongate, lower ones longer than upper ones, c e l l s cy l indr ica l f i laments , cel ls short , i r regular , constr icted at cross-walIs creeping f i l a -ments filaments elongate, branching alternate or i r regular , short, secund and scattered, branchlets < ID c e l l s la tera l branches blackish purple-brown or dark o l ive-green, laminate irregular margins dark steel-blue plastids el 1 ip t ic -d isco id , i r regular s i ight ly lobed margin: 2-4 per ce l l dark purple dark ol ive plast id parietal 2-4 per c e l l , laminate wi1 irregular undulated margins s ing le , i r regular lobed, parietal p last id co lo r l ess , L* 350; termin-ating vegeta-t ive and f ru i t i ng branches on short branches several times dicho-tomous or on lateral branches end in 1-2 monospores, spores ovate L-17-18; U-13.5-14.5 on branches of 1-3 c e l l s , scattered, opposite or v e r t i c i -l l a t e ; monosporangia ovate, s e s s i l e or on 1-cel led s ta lk , 2-4 or s i n g l e , usually corymbose, glonerately arranged 1*14-17; W-10-14 obovoid, sess i le or on unicel l s ta lk , opposi te or secund, ser ia te , on short branches 1-5 c e l l s , a l ternate or scattered (.=14-17; W-10-14 * ovate, on 1-celled s ta lk , rarely s e s s i l e , 2-3 per s t a l k , opposite; L=9-13.5; W=7-9 on latera l branches, single or aggregated L-7-10; W=5-8 LM8-45; W=9-14 L-16-36; W=7-9 L=42-72; H-9-10 L=9-22; K=5.4-7.2 L-5-10; w*4-7 on exposed dripping rocks 1n a pool connected to mountain spr ings, West China (color varied in hot and cold waters); Jao (1941). on rocks and submerged plants in a mounter stream in North China; Jao (1941). on concrete wall of mi l l dam, Northern China; Jao (1941) on rocks in a spr ing , well shaed by t rees, China; Jao (1940) small streams in Japan on moss mixed with Sangia  atropurpurea; Kunano (19?8) *Jsa Height Chloroplast-type and . . . 1] asexual species Habit . Basal System Erect System of Color Pyrenoids H a i r C e ' l s Sexual Monosporangium Tetrasporangium Main Axis Branch Ce l l s Habitat and References Plant Reproduction and Monospores and Tetraspores • Ce l l s Used (mm) C. pygmaea Kiitz. T645. C. ramellosa Kutz. C. s e r p e n s T s r a e l s o n 1942. C. s u b t l l i s Mobius T894. C. tenel la Skuja T934. forms brushlike bundles mats, hemisphe-r i c a l . Hansgirg (1902). Radiat-ing in a l l d i rect ions * + up to rhizoids f lxp lant branching sparse, a l ter - 15 to substrate nate or opposite at acute angle to main axis , c e l l s cy l indr ica l Mobius (1894) and filaments densely inter-filamentous twined, upper branches umbetlate, upright and . appressed. Mobius (1894). Cel ls c y l i n d r i -c a l , somewhat constr ict -ed at ends, rhizoids produced occasionally from basal c e l l s . 1-2 fi laments-upright rod-shaped, acute branches un iax ia l , singlebranch threads, lateral branches, protrude widely ( - 9 0 ° ) (Starmach 1977) creeping f i l a -ments, seldoraly developed, some branches constr ict ions at trans-verse wall of c e l l s not near apex, branches alternate or opposite in one plane, rhizoids develop creeping rhizoidal- uniser iate, no cor t i ca -l ike intei-wovon t ions, alternate to in cushion- l ike opposite branches, curv-layers ed at t ips , secund, transverse walIs con-st r ic ted grey , 'b lue , green some-times brown, plast ids parietal lobe- l ike black-violet -purple Hansgirg (1902) s tee l -blue, greenish or reddish 3.1- brownish, r o s y - r e d ol ive or dark green p last ids , r ibbon-l ike sometimes divided in segments (Starmach 1977) v io le t - red , one or more p las t ids , pa r ie ta l , spiral bands absent (Mobius 1894) ha i r l ike tips on lateral branches and sometimes terminal on main axis on lateral branches of 1-2 c e l l s , single or in pa i rs ; diameter 21-38 on side branches o f 3 c e l l s Starmach (1977) L-10-13; W=9-H terminal on short side branches or lateral or uni -la tera l round ( inversely ovate) s ing le , sess i le or on one eel led branches; L-9-11; W«7-8 L-7?-104; H-15-Z5 1 1/2-3 times longer than wide Mobius (1894) 10-14 diameter 1n pond epiphytic on s t icks and aquatic plants; Wolle (1887). .in small streams on boulders, German; Kutz. (1845); Hansgirg (1902); Mobius (1894). 4 times longer than wide L"30-60(-90); ' W-16-18 Starmach (1977) 2 times longer Kutz. (1945). than wide L-6-33; 5.5 in l i t t o r a l zones of lakes; Israelson (1942); Starmach (1977). epiphyt ic on H i te l l a (Aust ra l i a ) ; Mobius (1894). on emerged rocks (Ca l i forn ia USA); Skuja (1934). Irregular branched, branching alternate, rectangular ce l ls rarely opposite or secund, cy l indr ica l ce l ls single lobed parietal + plast id 1-2 per ce l l on 1-2 cel led bran-ches, occasional ly s e s s i l e , oblong spores leave at apex, ame-boid behavior; spherical or sub-spherical ; monospores L=14-20; W=13-16; monosporangium L=18-24.3; W-16-17 L-39-75; W«13-15 L=15-28; U=7.S-U - 3 (2-2.5 times longer than wide and at t ips 3-4.5 times longer) attached to wall in r iver , running water and on roots of Phoenix, India; Patel ( 1 9 7 0 7 : short polygonal lots alternate c e l l s , i r regular ly branching branched and l a t e r a l l y cohered well defined parietal absent p last ids; one per ce l l often lobed Ac. sarmaii Rahn" 1970V densely tufted decumbent creeping branches at acute f i laments; 10-12 angle with main axis diameter 2-3 or 4 c e l l s 4-5 single parietal and lobed plast id many on lateral branches, two types ( i ) terminal on branches limited growth, oblong ( i i ) sess i le on branch unlimited growth uni -la tera l ser ies , obo-void , regeneration seen, l iberated at apex; L=20.5-26; W=(i)14.5-15; (i i)21.5-23.4 two types ( i ) terminal on branches, oblong (11) la tera l and obovold 1iberated at apex, i ) L-9-18; W= 6-12; i f ) L-9-18; U= 10-12 L-54-72; W=7.2-7.6 on dead aquatic plants India; Raikuar (1967). 1-40-60; W=10-12 (base 55-60; apex 35-40) on moss in ou t l e t , Kahn (1970). 78 79 

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