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The chaetognaths of western Canadian coastal waters Lea, Helen Elizabeth 1954

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THE CHAETOGNATHS OP WESTERN CANADIAN COASTAL WATERS by HELEN ELIZABETH LEA  A THESIS SUBMITTED IN PARTIAL FULFILMENT OP THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ARTS i n the Department of ZOOLOGY  We accept t h i s thesis as conforming to the standard required from candidates f o r the degree of MASTER OF ARTS  Members of the Department of Zoology  THE UNIVERSITY OF BRITISH COLUMBIA October, 1954  ABSTRACT  A study of the chaetognath population i n the waters of western Canada was undertaken to discover what species were present and to determine t h e i r d i s t r i b u t i o n .  The plankton samples  examined were collected by the Institute of Oceanography of the University of B r i t i s h Columbia i n the summers of 1953 and  1954  from eleven representative areas along the entire coastline of western Canada.  I t was hoped that the d i s t r i b u t i o n study would  correlate with fundamental oceanographic data, and that the presence or absence of a given species of chaetognath might prove to be an indicator of oceanographic conditions.  Four species  of chaetognaths, representing two genera, were found to be present.  One species, Sagitta elegans. was the most abundant and  widely distributed species, occurring at least i n small numbers i n a l l the areas sampled.  I t was c h a r a c t e r i s t i c of the mixed  coastal waters over the continental shelf and of the inland waters.  Enkrohnla hamata. an oceanic form, occurred i n most  regions i n small numbers as an immigrant, and was abundant toward the edge of the continental shelf.  Sagitta l y r a . s t r i c t l y  a deep sea species, was found only i n the open waters along the outer coasts, and a few specimens of Sagitta decipiens. another oceanic form, were also taken i n deep hauls from areas exposed to open ocean influence.  I t was found that the outer l i m i t of  Sagitta elegans corresponded with the inner l i m i t s of a l l three oceanic forms, though Eukrohnia hamata invaded the inland waters to some extent.  TABLE OP CONTENTS Page 1.  INTRODUCTION  2.  HISTORY  3.  ZOOGEOGRAPHICAL DISTRIBUTION . . .  4.  OCEAN0GRAPHIC FACTORS INFLUENCING OCCURRENCE IN BRITISH COLUMBIA AFFINITIES OF THE CHAETOGNATHS  5.  .  1 .  2 3 . . .  6.  ANATOMY OF CHAET OGNATHS . . . . . . . . . . . . . . Geheralappearance Development and maturity stages  7.  MATERIAL  8.  TECHNIQUE OF EXAMINATION  9.  SPECIES IN BRITISH COLUMBIA Descriptions of Species Eukrohnia hamata Sagitta~eiegahs Sagitta l y r a Sagitta decipiens Keys to B r i t i s h Columbia Species  .  DISTRIBUTION AND FREQUENCY OF OCCURRENCE  11.  DISTRIBUTION IN EACH AREA I II III IV V VI VII VIII IX X XI  9  13 .  10.  4 7  16 19  . . . . .  34 36  Saanich Inlet Indian Arm Pehdrell Sound Channels north end S t r a i t of Georgia Bute Inlet Queen Charlotte S t r a i t Queen Charlotte Sound Hecate S t r a i t Dixon Entrance Masset Sound and Inlet West coast Queen Charlotte Islands  12.  EVALUATION OF THE DATA  . . . . . . . . . . . . . .  79  13.  SUMMARY . . .  80  14.  ACKNOWLEDGEMENTS  82  15.  LITERATURE CITED  84  LIST OF ILLUSTRATIONS  Plates Page I. Sagitta. diagrammatic drawing, ventral view . . . .  11  I I . Eukrohnia hamata, large maturing and small mature, dorsal views  . . . . .  21  I I I . Sagitta elegans, Sagitta decipiens^ and Sagitta l y r a , dorsal views  ...  . . .  . . . . . . . .  27  Maps I. Coast of western Canada, regions investigated . . . II. Saanich Inlet - stations  14  . . . . . . . . . . . . .  I I I . Indian Arm - stations  . . . . . . . .  40 .  45  IV. Pendrell Sound, Channels, and Bute Inlet - stations  48  V. Queen Charlotte S t r a i t - stations  58  VI. Queen Charlotte Sound and Hecate S t r a i t - stations VII. Dixon Entrance - stations  61 67  VIII. Masset Sound and Inlet - stations . . . . ,  73  IX. Queen Charlotte Islands - stations along west coast  77  Tables 1. Saanich I n l e t , d i s t r i b u t i o n of chaetognaths . . . .  41  2. Indian Arm, d i s t r i b u t i o n of chaetognaths  46  3. Pendrell Sound, d i s t r i b u t i o n of chaetognaths  ...  49  4. Channels north end S t r a i t of Georgia, d i s t r i b u t i o n of chaetognaths  . . . ...  . . . . . . . . . .  5. Bute Inlet, d i s t r i b u t i o n of chaetognaths  . . . . .  49 55  Page 6. Queen Charlotte S t r a i t , d i s t r i b u t i o n of chaetognaths.  59  7. Queen Charlotte Sound, d i s t r i b u t i o n of chaetognaths .  62  8. Hecate S t r a i t , d i s t r i b u t i o n of chaetognaths  62  9. Dixon Entrance, d i s t r i b u t i o n of chaetognaths  . . . .  68  10. Masset Sound and Inlet, d i s t r i b u t i o n of chaetognaths  . . . . .  74  11. West coast Queen Charlotte Islands, d i s t r i b u t i o n of chaetognaths  . . . . . . . . .  # » *  78  1.  INTRODUCTION  Chaetognaths, or arrow worms, are conspicuous members of the plankton communities of the oceans of the world.  More-  over i n some l o c a l i t i e s they have been found to be important indicator organisms, c e r t a i n species being confined to waters with c h a r a c t e r i s t i c properties.  When the requirements of var-  ious species are known, i t may be possible to predict the character and o r i g i n of a water mass on the basis of the presence therein of a p a r t i c u l a r species of chaetognath.  In the English  Channel, f o r example, where two species are predominant, the abundance of either one of the species gives information concerning the source of that p a r t i c u l a r water, and t h i s knowledge i s of value to the herring industry (Kemp,1938). While chaetognaths have been and are being studied extensively i n other parts of the world, including the east coast of Canada (Huntsman,1919), very l i t t l e i s known about the spec i e s present off the west coast of Canada or about t h e i r d i s t r i bution.  Except f o r the work of Michael (1909-1919) i n the San  Diego region of C a l i f o r n i a , there are no other published studies of chaetognaths f o r any area i n the eastern P a c i f i c .  Therefore,  the present study was undertaken to acquire information about the chaetognath fauna of the coastal waters of Canada's western province of B r i t i s h Columbia, and with the hope, a l s o , that the d i s t r i b u t i o n study would correlate with fundamental oceanographic data, and perhaps form a basis f o r more extensive studies.  plankton  2  2.  HISTORY  Chaetognaths were f i r s t discovered i n 1775 by Martin Slabber, who c l a s s i f i e d them as worms, and gave the species the generic name of Sagitta.  The arrow worm was not mentioned  again u n t i l 1827, when Quoy and Gaimard rediscovered It i n the Mediterranean and published a description under the name of Sagitta bipunctata.  They also c a l l e d i t i n French  "Fleche  deux points," or arrow with two dots, both names r e f e r r i n g to the shape and to the two black spots which they thought might be the eyes.  The description was very inadequate, since the  animals are transparent and the microscope used was not as good as the modern instruments.  Present day interest i n the  arrow worms dates from the publication of Quoy and Gaimard, but the confusion as to which species of arrow worm was Sagitta blpunctata was not cleared up f o r many years. Leuchart (1854) created the Order Chaetognatha (Gr. chaite, b r i s t l e ; gnathos, jaw).  Two  genera were recognized at  that time, one Sagitta (Slabber) and the other Spadella (Langerhans).  In 1883 Grass! produced a general work on the  whole group, but probably the most important taxonomic c o n t r i butions were made i n 1911 by Ritter-Zahony, whose careful and complete descriptions and good drawings have been the basis f o r a l l work on i d e n t i f i c a t i o n since that time.  Also important were  the contemporary works of Michael (1909, 1911) f o r the San Diego region.  Thomson (1947) i n A u s t r a l i a has brought up to date a l l  the Information on c l a s s i f i c a t i o n , technique, synonymy, and d i s -  3 t r i b u t i o n , and produced an excellent key f o r a l l v a l i d species besides compiling an extensive bibliography. Thomson, there are now one f o s s i l form.  According to  ten genera of chaetognaths, including  Seven of these genera are monospecific, i n  one genus there are two species, i n another three, and the genus Sagitta contains twenty-six v a l i d species.  Several forms that  have been described are s t i l l considered doubtful species, and further investigation w i l l be required, e s p e c i a l l y as to the environmental influence on the c h a r a c t e r i s t i c s used f o r c l a s s i fication.  3.  ZOOGEOGRAPHICAL DISTRIBUTION  While chaetognaths occur i n a l l oceans, the i n d i v i d u a l species are r e s t r i c t e d to d i f f e r e n t regions, some being deep sea forms, others l i v i n g i n the epiplankton of the open sea, and some inhabiting only the mixed waters over the continental shelves near land.  None of the species i s completely cosmo-  p o l i t a n , though many have a very wide d i s t r i b u t i o n .  Thomson  (1947) states that eight of the Indo-Pacific forms do not reach the A t l a n t i c , while f i v e A t l a n t i c species have not been reported from the Indo-Pacific.  Species of deep oceanic waters have a  wider d i s t r i b u t i o n than those dwelling near the surface, since they are subject to very l i t t l e temperature change, though i n the warmer parts of the world they are found at greater depths than they are i n the colder regions.  Also the immature stages  are often nearer the surface, while the mature ones are i n  4  deeper water.  Thomson says that the bulk of the chaetognath  population, as with the plankton i n general, i s concentrated in the upper one-hundred meters.  Some of the species l i v e at  much greater depths, however, and according to Ritter-Zahony (1911b) they have been taken at depths of over 1200 meters.  It  Is possible that some species could be found i n deeper hauls than are o r d i n a r i l y made.  Praser (1949) states that one speci-  men of Krohnitta subtalis (Grassi) was taken where the depth exceeded 1800 meters. In a regional study, one must be aware of the fact that the chaetognath population may vary with the season, from one year to another, or with s h i f t s i n the currents.  Some intensive  regional studies have been undertaken, but much of the informat i o n available at present has been obtained through examination of material c o l l e c t e d on occasional expeditions.  As more regions  are thoroughly studied, i t w i l l be possible to form a much better picture of the global d i s t r i b u t i o n of the chaetognaths.  4.  0CEAN0GRAPHIC FACTORS INFLUENCING OCCURRENCE IN BRITISH COLUMBIA  In the north P a c i f i c Ocean, the chaetognath fauna has been investigated i n the Philippines (Michael,1919), i n Japan (Tokioka,1940), and In southern C a l i f o r n i a o f f San Diego (Michael,1909,1911).  I t might be expected that species found  i n any of these regions could also occur i n the B r i t i s h waters.  Columbia  The North Equatorial Current flowing past the P h i l i p pines becomes the Euroshio Current along the south and east of Japan.  Here i t i s joined by cold waters from the north and con-  tinues eastward across the P a c i f i c , approaching the coast of America i n the v i c i n i t y of Vancouver Island.  About four hundred  miles offshore i t divides, part turning north and the remainder south (fully,1953).  I t c l o s e l y approaches the shore i n the  region of the northern Queen Charlotte Islands and Dixon Entrance. Some of the waters of the Japanese Current pass along the coast of B r i t i s h Columbia as the southerly flowing Alaskan Current.  This current follows a serpentine path to and from  shore, according to T u l l y (1937). The coastal counter current carrying the fresh waters drained from the land, e s p e c i a l l y by the r i v e r s large and small, tends to flow northward along the coast from San Diego to the Aleutian Islands of Alaska.  Off the west coast of Van-  couver Island, t h i s current flows northwestward regardless of the ebb and flow of the t i d a l currents, though part of i t i s dissipated i n the gyros of the Alaskan current.  The  counter  currents are strongest i n May and June, when the spring freshets of the big r i v e r s reach the sea.  At t h i s time the counter cur-  rents are ten or more miles wide and carrying a layer of brackish waters at the surface, but l a t e r i n the season they recede as the r i v e r flow decreases (Tully,1953').  A marginal  turbulence  between the coastal and the Alaskan currents i s present,  and  zones of sinking and r i s i n g waters occur throughout the area  6  (Tully,1937). The d i s t r i b u t i o n of the f i s h i n the waters of B r i t i s h Columbia i s known.  Sub-arctic, sub-tropic, and temperate spe-  cies are found i n various areas at a l l times of the year, or are seasonal or occasional v i s i t o r s (Clemens and Wilby,1946). The oceanic isotherm of the sub-tropical zone, which i s oppos i t e San Francisco, curves northward and reaches the shores of the Queen Charlotte Islands and farther north.  Sub-arctic tem-  peratures occur north of that to the Aleutian Islands.  Off  shore at the surface of the ocean, where the water i s warmer, the southern forms of f i s h are found.  The northern species  occur i n deep water, or may appear i n the upwelled cold water near shore. In view of the facts just presented as to oceanic currents, temperatures, and the known d i s t r i b u t i o n of f i s h , i t was expected that there would be a varied chaetognath fauna along the western Canadian coast.  F i f t e e n species have been i d e n t i -  f i e d from the P h i l i p p i n e s , eighteen from Japan, and thirteen from San Diego.. However, four species.only, representing two genera, were collected from the areas sampled i n Canada.  One  additional species has been i d e n t i f i e d from the region (Sagitta planetonls) by Dr. J.M. Thomson of A u s t r a l i a f o r Mr. R. Le Brasseur, student of the University of B r i t i s h Columbia.  The  specimen may have been an i s o l a t e d immigrant, since i t was not found i n the present survey, either i n the region from which i t had been reported or from any other.  Since no stations were  located i n the deep waters o f f the coast or beyond the contin-  7  ental shelf, future work i n the deep ocean could reveal the presence of many more species. The species found at any time i n the B r i t i s h Columbia waters and t h e i r presence or absence i n the other three regions of the north P a c i f i c ocean, where the. chaetognath fauna has been investigated, are shown i n 'the following table:  PHILIPPINES JAPAN CALIFORNIA (Michael,1919) (Tokioka,1940) (Michael,1911)  In order of Abundance Sagitta elegans  -  +  -  Eukrohnia hamata  +  -  +  Sagitta l y r a  -  +  +  +  -  -  +  Sagitta decipiens i Sagitta planctoriis  +  The d i s t r i b u t i o n i s of i n t e r e s t , though there i s insuff i c i e n t information about the l i f e h i s t o r i e s of the d i f f e r e n t species and t h e i r occurrence i n intervening areas to draw s i g n i ficant conclusions.  5.  AFFINITIES OF THE CHAETOGNATHS  The position of arrow worms i n the Animal Kingdom i s uncertain.  The Phylum Chaetognatha i s usually grouped with  miscellaneous other small phyla and the issue avoided.  In the  8 Zoological Record chaetognaths are found under "Vermes." Burf i e l d (1927) says that they have been c l a s s i f i e d variously as Coelenterata, Nemathelminthes, Arthropoda, Mollusca, Vertebrata, Enteropneusta, and Annelida, but suggests that the chaetognaths probably originated from a very ancient, freeswimming stock, having a coelora s t i l l communicating with the gut, and c a l l e d Protocoelomata by some writers.  According to  t h i s theory, a l l coelornate animals have descended from that hypothetical stock, and the Chaetognatha would be considered as a very ancient and not greatly modified offshoot.  Walcott (1911)  found adult chaetognaths i n B r i t i s h Columbia Middle Cambrian shales which were very much l i k e the young animals of the present day just emerged from the egg, since there was no t a i l septum and the i n t e s t i n e terminated a l i t t l e beyond the center of the tail. Meek, discussing the c l a s s i f i c a t i o n i n 1928, mentions the same long l i s t of phyla to which the arrow worms had at some time been assigned, adding Echinodermata, Rotifera, and Brachiopoda.  He says that i t has long been known that developmentally  the Chaetognatha come c l o s e l y into relationship with the Echinodermata and the Enteropneusta.  The s t r u c t u r a l features of the  adult, however, have been a puzzle and have lead to the confusion  i n classification.  Meek thinks that chaetognaths are almost  vertebrate i n t h e i r organization, and that the Echinodermata, Enteropneusta, and Pterobranchia present such an assemblage of similar characters, sharing besides such a p e c u l i a r i t y of development, that he proposes the combination of a l l four groups into a  9  new phylum, c a l l e d Hydrocoela.  6.  ANATOMY OP CHAETOGNATHS  Arrow worms are slender, transparent animals, the l a r gest of which may reach a length of over seven  centimeters.  The body i s divided by transverse septa into head, trunk, and t a i l regions.  Delicate f i n s along the sides are used f o r b a l -  ance and buoyancy rather than f o r swimming, and there i s also a caudal f i n at the end of the t a i l .  On the head are l a t e r a l  hooks and two paired rows of teeth used f o r s e i z i n g prey and crambing:$?t into the ventral mouth.  A hood, o r i g i n a t i n g i n the  neck region, p a r t l y covers the hooks.  The eyes usually appear  as two dark spots on the dorsal surface of the head.  On the  trunk a prominent structure i s the swollen ventral ganglion located on the ventral surface toward the anterior end.  Just  anterior to the t a i l septum i s the anal opening, and the surrounding tissues may be quite enlarged and protruding.  In the  larger specimens, spots consisting of groups of sensory f i b e r s may be seen scattered r e g u l a r l y over the surface of the body and the f i n s . Since the animals are transparent, the i n t e r n a l organs may also be seen.  The i n t e s t i n e i s a straight tube leading  from the mouth to the anus, the part i n the head often being c a l l e d the pharynx.  Mature or maturing specimens have ovaries  extending forward from the t a i l septum and seminal v e s i c l e s projecting l a t e r a l l y at the sides of the t a i l .  Chaetognaths  10  usually have longitudinal muscles only, and they swim i n short, vibrating spurts. In the i l l u s t r a t i o n , (Plate I ) , the most obvious external and i n t e r n a l structures, which include those for  necessary  species i d e n t i f i c a t i o n , are drawn and labeled. Very small chaetognaths just emerged from the egg look  l i k e adults, though the proportions are d i f f e r e n t .  The t a i l i s  longer, and the ventral ganglion, which does not increase much in s i z e as the animal grows i n length, i s almost as long as the trunk.  Meek (1928) presents an excellent diagram of the r e l a -  t i v e rates of growth of the various parts of the body of Sagitta elegans. The animals lengthen considerably before they start to mature, though the length at maturity i s greatly influenced by the temperature of the water.  Individuals of a given species  mature e a r l i e r i n warmer water, and i n cold water often grow to a comparatively large s i z e before maturing. Chaetognaths are hermaphroditic  and protandric.  A des-  c r i p t i o n of the maturity stages of Sagitta elegans, as observed during t h i s study, w i l l serve to i l l u s t r a t e f a i r l y well the development of chaetognaths i n general.  The male reproductive  organs are located i n the t a i l , and eventually the entire t a i l becomes completely f i l l e d with sperms. est  Even before the s l i g h t -  trace of ovaries can be seen, the t a i l may  be so f u l l of  spermatocytes and sperms as to be opaque and yellow i n c o l o r . The seminal v e s i c l e s then begin to push out at the sides of the tail.  At t h i s time, short, r o d - l i k e ovaries make t h e i r appear-  ance.  The seminal v e s i c l e s grow r a p i d l y and the sperms are ex-  ANTERIOR  TEETH  POSTERIOR  HOOD  ANTERIOR  -TACTILE  TEETH  SEPTUM  PAPILLA  -VENTRAL  GANGLION  -INTESTINE  -ANTERIOR  -OVA  FIN  RY  -OV I D U C T  -POSTERIOR  .FEMALE -SEMINAL .ANUS -TA I L  FIN  A P E R T U R E R E C E P T A C L E  SE P T U M  -T E S T I S  -VAS  DEFERENS  -SEMINAL  CAUDAL  PLATE  I.  SAGITTA.  D I A G R A M M A T I C  VESICLE  FIN  DRAWING  -  V E N T R A L V.EW  12  traded by the time the ovaries are completely mature.  The  tail  i s then l e f t empty and transparent, and the spent seminal vesi c l e s are empty and ragged-looking.  The shape of the seminal  vesicles and t h e i r location on the t a i l i n r e l a t i o n to the l a t e r a l and t a i l f i n s are of s p e c i f i c importance, and when present they are an excellent recognition c h a r a c t e r i s t i c . As the ovaries mature they elongate, the length to which they reach a n t e r i o r l y varying with age and species.  In the  early stages they appear slender and r o d - l i k e , the eggs a l l being small and of the same s i z e .  As some of the eggs increase  i n s i z e , the ovaries become broader and bunchy i n appearance. In mature individuals the ovaries have reached t h e i r extreme length and a l l the eggs are large.  Animals that are about  spent have a few large eggs scattered along the length of the ovaries with empty spaces between.  Extrusion of the eggs ap-  pears to complete the l i f e cycle f o r almost a l l species of chaetognaths, though Sagitta enflata, according to Thomson (1947) i s thought to have two cycles of reproduction.  Of  Sagitta elegans. Meek (1928) says, "It i s evident that, a f t e r spawning as females, Sagitta disappears, or apparently disappears, and i t may be therefore that the end of maturity i s also the end event of l i f e . "  In discussing t h i s aspect of the  chaetognath l i f e history, Meek stated that two generations of S.elegans seem to develop each year i n the Northumbrian waters, one spawning i n the Spring and the other i n the Autumn.  On the  other hand, Russell (1933) says that "Sagitta i s an animal which passes through several generations i n the year, possibly f i v e or  13  six according to the species.  11  In the cold polar waters of the  Canadian eastern A r c t i c with temperatures of 1°C or below, Dunbar (1941) found that the a r c t i c sub-species of Sagitta elegans takes two years to reach maturity. Reading of Sagitta by B u r f i e l d (1927) i s indispensable for a complete study of the anatomy and development of chaetognaths.  The subject of the Memoir i s Sagitta bipnnctata.  7.  MATERIAL  The c o l l e c t i o n s studied i n t h i s investigation were made by Dr. Robert F. Scagel, assistant professor of oceanography, during cruises of the C.G.M.V.Cancolim I I i n 1953 and of the C.N.A.V.Ehkoli i n 1954.  Almost a l l of the material was c o l -  lected from June 12 to September 5 i n 1953, but one region was v i s i t e d and hauls made on May 21 and 22 i n 1954.  The stations  were located i n a variety of areas extending from the northernmost to the southernmost part of the P a c i f i c coast of Canada, as indicated on the map, Map I, and a study of the hauls gives a f a i r l y accurate o v e r a l l picture of the d i s t r i b u t i o n of the chaetognath population at that time, with the exception that there were no stations along the west coast of Vancouver Island nor i n the deep waters of the P a c i f i c Ocean.  Since the cruises  were not planned f o r the purpose of t h i s investigation, and plankton hauls were not made at every station occupied, i t i s fortunate that the stations at which hauls were made were so well placed f o r a population and d i s t r i b u t i o n study of the  15  entire region.  The material available f o r study included 139  hauls from 113 stations.  Several hauls were made at some of  the stations where the ship was anchored f o r extensive oceanographic surveys. The hauls were made with a #10 nylon net having a diameter of t h i r t y inches, the net being drawn v e r t i c a l l y from the bottom to the surface. f o r temperatures, levels.  At every station data were recorded  s a l i n i t i e s , and oxygen content at various  Since these data are indispensable i n a d i s t r i b u t i o n  study, as much use as possible was made of the information. However, when specimens are taken i n v e r t i c a l hauls, there i s no way of knowing at what depth the chaetognaths were taken and what oceanographic  conditions actually prevailed at that  particular level. The samples were preserved i n A% formalin, which has been found to be the best preservative f o r chaetognaths, and most of the specimens were i n very good condition. An unsuccessful attempt was made to keep specimens a l i v e i n the laboratory f o r a study of t h e i r development and a c t i v i t y , besides a more accurate examination  of t h e i r anatomy.  The chaetognaths were collected during two winter cruises made by the Institute of Oceanography of the University of B r i t i s h Columbia.  The animals were put immediately  into t e n - l i t e r jugs.  The f i r s t specimens collected were not aerated, but a second c o l l e c t i o n was made i n which aerators, taken on the cruise f o r the purpose, were put into use as soon as the specimens were taken.  Upon a r r i v a l at the laboratory the jars were immersed  16  i n previously prepared water baths at 7°C, an average winter water temperature i n the l o c a l i t y i n which the specimens were taken.  However i n both cases the arrow worms were dead the  next day.  B u r f i e l d (1927) also found that he was unable to  keep specimens a l i v e f o r more than twenty-four hours, though he was able to use running sea water.  8.  TECHNIQUE OF EXAMINATION  Chaetognaths do not require staining f o r examination. If the specimens have been well preserved, they can be examined most e a s i l y by f l o a t i n g them i n a l i t t l e of the 4% formalin i n which they have been preserved. Because of t h e i r s i z e , preliminary examination with a binocular microscope i s s a t i s f a c t o r y .  Evenually, when the  species have become e a s i l y recognizable, the use of the binocular microscope i s a l l that i s necessary.  Any specimen  that  looks d i f f e r e n t can then be examined more c l o s e l y under a compound microscope. For examination of the animals, some type of container i s required that w i l l hold enough f l u i d to cover the specimens, but keep them from f l o a t i n g around too much, and be f l a t enough to be used with a compound microscope.  Rectangular c e l l s b u i l t  up on two sizes of s l i d e s with waterproof p l a s t i c glue met the requirements. 1 3/4  w  On a large two by three inch s l i d e the c e l l  long by 1 l / 4  tt  wide.  was  This was long enough f o r a l l speci-  mens found and wide enough to hold a row of ten or more chaetognaths at the same time f o r rapid examination with the binocular  17  microscope. 5/8°.  On a standard-sized s l i d e the c e l l was 1 l/2» by  This size was useful f o r viewing one to a few specimens  at a time with the compound microscope.  The c e l l was enough  smaller than the large one to prevent the animal*s f l o a t i n g out of view.  These two c e l l - s l i d e s were indispensable during the  entire course of the work. To remove the animals from the plankton sample, i t was found that the best method was to pour a r e l a t i v e l y thin layer of the sample into a p e t r i dish. square of black paper.  Under the p e t r i dish was a  Most of the larger animals could be seen  without l i f t i n g the dish, but some were seen more e a s i l y i f the dish was picked up and rocked slowly.  The binocular microscope  was often used f o r the f i n a l examination, though not always. Any chaetognaths that were caught i n the net used could be seen with the naked eye, the very smallest being almost two m i l l i meters long. As the animals were picked out of the sample, they were put into another p e t r i dish containing the &% formalin.  In t h i s  the copepods, other animals, and plants that had stuck to them were washed o f f . The chaetognaths were then transferred a few at a time from t h i s dish to the s l i d e with the large c e l l f o r examination under the binocular microscope. done with a p a i r of curved forceps.  A l l handling was  The animals were picked up  j u s t posterior of the neck region to avoid injury to the f i n s . Measuring was done with a t h i n , f l a t , transparent r u l e r . was e a s i l y slipped under the s l i d e .  This  18  For more thorough examination of the f i n s , or i n order to see and count the teeth and hooks, the animals were usually transferred to the small c e l l - s l i d e .  It takes a great deal of  patience to become adjusted to seeing the teeth.  I t was found  that special l i g h t i n g and adjustment of the microscope  was  required before they could be seen well enough to count. technique employed involved the use of hollow-cone  The  illumination.  Various l i g h t f i l t e r s were t r i e d , but green proved to be the most effective.  Polarized l i g h t was a d i s t i n c t a i d i n some cases,  and a phase retardation plate helped to d i f f e r e n t i a t e structures. The special l i g h t i n g technique was developed by Dr. Kenneth Graham, professor of forest entomology, of the University of B r i t i s h Columbia, to whom the writer i s greatly indebted.  The  d e t a i l s i n regard to increasing image contrast by the use of hollow-cone illumination are described by Mathews (1953). To determine the number of specimens present i n each sample, the entire sample was examined and a l l specimens were removed.  These were counted and the numbers of mature, matur-  ing, and immature individuals were recorded as shown i n the tables.  The sizes of the largest and smallest specimens of  each were also recorded.  Individuals of Sagitta elegans were  c l a s s i f i e d as mature i f they had well developed ovaries and seminal v e s i c l e s ; maturing i f they had rod-like ovaries and also had seminal v e s i c l e s ; and immature i f there were no semina l v e s i c l e s , even though i n some cases very small ovaries could be seen.  Individuals of the other three species were designated  as maturing i f they had ovaries but no seminal v e s i c l e s , and im-  mature i f they had no ovaries.  9.  SPECIES IN BRITISH COLUMBIA  Four species only, representing two genera, were found to occur i n the areas studied.  These species are:  Sagitta elegans V e r r i l l (1873) Sagitta l y r a Krohn (1853) Sagitta decipiens Fowler (1905) Eukrohnia hamata (Mtfbius, Two  1875)  of these species, Sagitta elegans and Eukrohnia  hamata, were common, while the other two were found i n small numbers only i n the open ocean waters of the Queen Charlotte Islands and i n Queen Charlotte Sound.  It i s not d i f f i c u l t to  d i f f e r e n t i a t e the species, but S.elegans presents some problems since i t varies from region to region s u f f i c i e n t l y i n transparency, proportions, and i n numbers of hooks and teeth to just i f y the recognition of three  sub-species.  In the descriptions of the species which follow, to f a c i l i t a t e the i d e n t i f i c a t i o n of the l o c a l species whether young or mature, observed p e c u l a r i t i e s and c h a r a c t e r i s t i c s are included that are h e l p f u l , but would not be encountered i n the keys or i n more formal descriptions.  Eukrohnia hamata (Plate II) This species, not as abundant as S.elegans. but apt to be present i n small numbers i n most regions of B r i t i s h Columbia  20  can not be confused with any other.  Even i n a dish f u l l of  chaetognaths, i t appears d i f f e r e n t to the naked eye.  Speci-  mens bent almost at r i g h t angles i n the region of the ventral ganglion frequently prove to be t h i s species.  The bending may  possibly be due to l o c a l i z e d muscular disintegration following the  animal's entrance into water of low s a l i n i t y , as the spe-  c i e s i s an oceanic form.  Ritter-Zahony (1911a) remarked  that  some individuals of E.hamata he observed were uncommonly transparent and appeared to be undergoing a slow muscular atrophy. Besides the bending, there i s often marked curvature of the entire body.  Also, the animals are ragged-looking along the  sides, and debris i n the form of copepods, other animals, or algae i s frequently entangled i n the l a t e r a l or t a i l f i n s or in the hooks.  Under the binocular microscope, E.hamata i s con-  spicuous because of the large o i l droplets i n the i n t e s t i n e s . In addition the hooks are usually spread, and there i s a d i s t i n c t neck, making the head appear broad.  The f i n s , wide,  d e l i c a t e , and sparsely rayed, one pair to each side, extend from i n front of the ventral ganglion to half way down the tail.  The t a i l has an angular appearance, while other species  have smoothly tapering t a i l s .  I f the animal appears to have  no eyes, one can be almost sure that the specimen i s E.hamata. since individuals l i v i n g i n cold water have no pigment i n t h e i r eyes (Thomson,1947), and none of those found i n B r i t i s h Columbia  waters did have pigment.  Examination under the compound  microscope reveals conspicuously serrated hooks i n young i n d i viduals.  Also while most chaetognaths, including a l l the others  P L A T E II.  E U K R O H N I A  H A M A T A . L A R G E MATURING AND SMALL MATURE - DORSAL VIEWS  22.  found i n B r i t i s h Columbia, have two paired rows of teeth, Eukrohnia has only one paired row. Out of the 1018 individuals of E.hamata taken i n the entire survey, 1002 were immature, 15 had rod-like or short ovaries, and only one was f u l l y mature.  The completely matured  specimen had a peculiar appearance, with the trunk almost ent i r e l y f i l l e d with large eggs, and the t a i l swollen to about twice the size of the trunk.  The drawing, Plate I I , shows a  large maturing specimen with three conspicuous o i l droplets and the much smaller mature i n d i v i d u a l mentioned above. Though, as previously stated, E.hamata i s an oceanic form, unlike the other deep sea species, i t had found i t s way into the shallow waters of many of the inland passages and i n l e t s of B r i t i s h Columbia.  According to Ritter-Zahony  (1911b),  i n the tropics t h i s species occurs at depths of from 400-1000 meters, but i n the north i t may be found near the surface as well as i n the deep waters.  Sagitta elegans (Plate I I I ) This i s the most abundant and widely distributed species i n the region.  S.elegans, unlike E. hamata, has two pairs  of f i n s along the sides.  The posterior ones are r e l a t i v e l y  long, broad, firm, and oval-shaped, with a greater proportion on the trunk than on the t a i l .  The anterior f i n s are some d i s -  tance back from the ventral ganglion and are shorter and narrower than the posterior ones. rayed.  Both pairs are completely  Sometimes on preservation the sides of the trunk f o l d  23  i n , and the anterior f i n s are folded out of sight.  If the  f i n s can not be seen, they w i l l be exposed by f l a t t e n i n g the body gently i n the f i n region. The neck of S.elegans i s broad, and the head usually does not look any wider than the body.  However, should the  animal be k i l l e d i n the act of eating, the head w i l l appear very wide, and the hooks may even be inserted into the mouth.  Very  relaxed specimens may have the hooks spread. S.elegans i s usually quite s t i f f and sometimes opaque, but most specimens taken i n B r i t i s h Columbia were transparent and many were flabby.  The species usually has ten hooks, but  though the number varies from eight to thirteen, there are never less than eight.  The only other species i n the region  with which i t could be confused, S.decipiens. never has more than seven.  The teeth are d i f f i c u l t to see and count, espe-  c i a l l y i n the more opaque specimens, but there are two paired rows of them, and they increase i n number as the animals grow longer. Mature individuals have prominent, c o n i c a l , seminal v e s i c l e s on each side of the t a i l , either touching the t a i l f i n or very close to i t , and distant from the posterior f i n s .  The  eggs are large and the ovaries extend well forward into the body cavity.  The younger but maturing specimens have f l a t t e r  seminal vesicles and slender rod-like ovaries, very short and inconspicuous i n the youngest animals, but elongated and p l a i n l y v i s i b l e i n those approaching maturity. Sagitta elegans varies s u f f i c i e n t l y from one region to  24  another to have made i t necessary to divide the species into three sub-species.  The sub-species, as designated by R i t t e r -  Zahony, (1911c), are S.elegans elegans. S.elegans a r c t i c a . and S.elegans b a l t i c a .  Both Ritter-Zahony and more recently Hunts-  man (1919), who investigated the sub-specific differences thoroughly f o r the species i n eastern Canadian waters, agree as to the general c h a r a c t e r i s t i c s separating them. for  The figures used  length of body and t a i l proportions i n the following des-  c r i p t i o n s are Dr. Huntsman's. S.elegans b a l t i c a i s the smallest of the three forms, the largest caught i n eastern Canada measuring 26 millimeters. The t a i l i s shortest i n proportion, ranging from 14-19$ of the entire body, 16$ being the usual proportion.  This  sub-species  has s l i g h t l y fewer hooks; eight i n the smaller specimens, i n creasing to ten i n longer ones, and decreasing to eight again i n the longest.  The maximum number of teeth attained i s also  lower than i n the other sub-species.  The B a l t i c form i s more  flabby, limp, and transparent than the others; the anterior f i n s are somewhat smaller; and the ovaries are shorter, reaching  no farther than the anterior end of the posterior f i n s . S.elegans a r c t i c a grows to the largest s i z e , the long-  est  specimen obtained by Dr. Huntsman measuring 52 millimeters.  The t a i l i s long i n proportion, ranging from 19-22$, with 20$ being most frequent.  A greater number of hooks develop, the  number increasing from eight to twelve as the animals lengthen, and there i s no decrease i n the longest specimens as i n the B a l t i c form.  The number of teeth also increases as the animals  25  grow longer, more being present eventually than i n the two other sub-species.  The a r c t i c form i s more opaque and  stiff  than the others, and the ovaries extend farther forward i n the trunk. S.elegans elegans i s the intermediate form, the maximum  length being 36 millimeters i n eastern Canada.  varies from 16-20#, usually being 11% of the body.  The  tail  The hooks  increase from eight to eleven and, as i n the a r c t i c form, there i s no decrease as the animals grow longer.  The number of teeth  and variations i n the f i n s , length of ovaries, and transparency i s also intermediate. Dr. Huntsman says that the differences between the three sub-species are caused by differences i n temperature development.  during  He found that the t a i l percentages did not vary  much i n the young individuals of the three kinds and concluded that t h i s was due to the fact that the young of a l l occurred near the surface, where the water was r e l a t i v e l y warm and the temperature  did not vary much from one region to another.  How-  ever, the older individuals occupy the deep water, which does vary i n temperature from place to place, and i n these older animals differences i n t a i l percentages appear.  RLtter-Zahony  (1911b) attributes the differences between the sub-species to the variation i n the s a l i n i t y of the water. In the early stages of the work in. i d e n t i f i c a t i o n of the species i n the western Canadian waters, there was some delay  caused by the fact that Michael had confused S.elegans with  some other species i n his i d e n t i f i c a t i o n i n 1911  (Plate 2,  26  p. 173) and i n h i s key i n 1919, i n which he located the seminal vesicles adjacent to the posterior f i n s rather than adjacent to the  tail fin.  Later, a f t e r t h i s d i f f i c u l t y was cleared up, the  sub-specific differences seemed great enough at times to cause some doubt as to the species observed.  Consequently Dr. J.M.  Thomson, senior research o f f i c e r of the Commonwealth  Scienti-  f i c and Industrial Research Organization, D i v i s i o n of F i s h e r i e s , in A u s t r a l i a was requested to i d e n t i f y specimens from Canadian waters.  This he kindly consented to do, and sixteen unlabeled  specimens, including thirteen S.elegans of a l l s i z e s , proportions, stages of maturity, and differences i n transparency were sent to him. His  Specimens of S.lyra and S.decipiens were included.  i d e n t i f i c a t i o n s confirmed the conclusions reached by t h i s  investigator, and cleared up a l l doubt as to the i d e n t i f i c a t i o n of S.elegans i n a l l i t s forms. In the d i s t r i b u t i o n survey of the species i n the western Canadian waters, no attempt was made to d i f f e r e n t i a t e between the sub-species. Neither d i d Dr. Huntsman f i n d i t worth while to consider them separately i n h i s work i n eastern Canada, since he found the sub-species were not d i s t i n c t but were connected by intermediates.  Fraser (1937) also observed that  there i s very l i t t l e clear-cut difference between the v a r i e t i e s of S.elegans, and that a complete sequence of types can be found. In the entire survey, 9564 specimens of S.elegans were taken.  Of this 654 were mature, 473 maturing, and 8437 were  immature.  There were almost ten times as many S.elegans as  27  s. E L E G A N S  P L A T E III. S A G I T T A  S. LYRA  E L E G A N S , S . D E C I P 1 E N S . AND S . L Y R A  - D O R S A L V.EWS  28 there were E.hamata, which was second i n abundance.  In ad-  d i t i o n , 12% of the specimens of S.elegans were mature or maturing,  compared with 2% f o r E.hamata. S.elegans has now been d e f i n i t e l y established as the  dominant species of chaetognath on both sides of the northern A t l a n t i c and P a c i f i c oceans, l i v i n g i n the c o l d , l e s s s a l i n e waters of the continental shelves.  In eastern Canada, Dr. Hunts-  mans c a l l s i t "the c h a r a c t e r i s t i c Sagitta of our A t l a n t i c waters, because of i t s general occurrence i n the shallow water a l l along the coast.  Very few specimens were collected by him i n the deep  waters beyond the continental shelf,.  Tokioka (1940) states that  S.elegans i s common i n the cold waters of north-east Japan.  Ritter-Zahony  Tyosen i n  (1911b) found that i t inhabited the north-  ern European coasts, and Meek (1928) found that i t was most often the dominant species i n the Northumbrian plankton,  while  Fraser (1937) stated that i t was dominant where A t l a n t i c water mixes with the coastal waters of western and northern  Scotland.  The species does not occur i n the southern hemisphere.  Sagitta l y r a (Plate III) This species i s s t r i k i n g l y d i f f e r e n t from either E.hamata or S.elegans. The body i s flabby and exceedingly parent.  trans-  The entire trunk appears wide, c o n s t r i c t i n g abruptly at  the neck and also at the t a i l septum.  The head i s broad and,  in contrast to the transparency of the body, i s opaque, while the t a i l i s noticeably slender and very transparent.  The two  pairs of l a t e r a l f i n s are d e l i c a t e and sparsely rayed, the  w  29  anterior ones being longer than the posterior.  Because the  f i n s are joined together, they appear almost l i k e the single l a t e r a l f i n s of E.hamata,however they do not extend as f a r f o r ward, reaching just short of the ventral ganglion, rather than extending anterior of i t .  The caudal f i n s appear both d e l i -  cate and unusually large.  The rich-brown-colored  hooks are con-  spicuous i n comparison with the tan ones of the other species. The location of the anal opening i s d i s t i n c t i v e i n S.lyra.  In  most species, including the others found i n B r i t i s h Columbia, the opening i s adjacent  to the t a i l septum, but i n S.lyra i t i s  very d e f i n i t e l y anterior of the t a i l septum. S.lyra are also c h a r a c t e r i s t i c .  The teeth of  They are often very few i n  number, and the anterior ones are long and projecting upwards. The western Canadian specimens had only two to four anterior teeth and two to seven posterior ones i n each row, ber i s variable, and large specimens may  but the num-  have as many as eight  anterior teeth on each side and up to twelve i n the posterior rows. Of the s i x specimens taken, only two were maturing and had very slender rod-like ovaries.  The longest one, twenty-  eight millimeters, had seminal vesicles just s t a r t i n g to develop. Mature specimens have small, conical ones l y i n g half way between the posterior and t a i l f i n s (Ritter-Zahony, the transparent  1911a, I l l u s . ) .  In  t a i l , unlike S.elegans with i t s opaque t a i l , the  male reproductive  organs are p l a i n l y v i s i b l e .  This species  grows to a very large s i z e , and while animals over f o r t y to f i f t y millimeters are seldom captured, Ritter-Zahony  (1911a)  30  gives seventy-one millimeters as the maximum size f o r S.gazellae, which i s now  considered the cold water form of S.lyra.  S.lyra i s an almost cosmopolitan  oceanic form usually  found at a depth of 300-1000 meters, according to Ritter-Zahony (1911b).  He found the young ones i n the epiplankton and the  mature ones deeper i n the mesoplankton.  The specimens obtained  i n the B r i t i s h Columbia region were taken along the west coast of the Queen Charlotte Islands, none occurring i n any of the inland waters.  Sagitta decipiens (Plate III) This species resembles S.elegans somewhat. s t i f f and transparent and the f i n s d e l i c a t e .  The body i s  The l a t e r a l f i n s  are separated as i n S.elegans. but the anterior ones are longer than the posterior and reach almost to the ventral ganglion. The caudal f i n i s small, and the t a i l i s proportionately longer than i t i s i n the other two species of Sagitta i n the region. In those taken the t a i l was 25$ of the t o t a l body length, but the possible range generally given i s 20-31$. i n h i s o r i g i n a l description, gives 25-40$.  Fowler (1905),  Compared with the  usual 16-20$ f o r S.elegans and 16$ f o r S.lyra, 25$ i s noticeable.  The head i s usually d e f i n i t e l y wider than the body,  rather rectangular i n shape, and also quite transparent.  The  hooks are slender, scarcely pigmented, and few i n number, varying  from f i v e to seven.  were observed.  Specimens with f i v e , s i x , and seven  S.elegans does not have l e s s than eight.  The  eyes of S.decipiens are c h a r a c t e r i s t i c and d i f f e r e n t from those  31  of  other chaetognaths (Ritter-Zahony, 1911a, I l l u s . ) .  They  are longer than wide, looking l i k e two joined slender beads. The species i s a small one, seldom reaching f i f t e e n m i l l i meters.  Though Ritter-Zahony (1911c) stated that i t attained  a size of twenty millimeters, Thomson (1947) gives twelve to thirteen millimeters f o r mature specimens i n A u s t r a l i a .  The  largest taken i n B r i t i s h Columbia was fourteen millimeters long and not f u l l y mature. Pour excellent specimens of S.decipiens were taken, as well as three others damaged beyond certain i d e n t i f i c a t i o n . The four that were d e f i n i t e l y S.decipiens had well developed ovaries, the longest reaching to the posterior end of the ante r i o r f i n s , but none had seminal v e s i c l e s .  The t a i l s were  c l e a r , and though one contained quite a number of transparent sperms, the t a i l was not opaque, as i n S.elegans at the same stage of maturity.  Neither were the t a i l s as transparent as  those of S . l y r a . since the internal male reproductive organs were not v i s i b l e .  Ritter-Zahony (1911a) and Michael (1919)  have pictured the seminal vesicles of S.decipiens as comma shaped, widest at the anterior end, and adjacent to the t a i l fin. S.decipiens. l i k e E.hamata and S.lyra, i s an oceanic form, which according to Ritter-Zahony (1911b) i s found between 200 and 1200 meters.  As with S.lyra, the mature forms  are also found at the greater depths.  The B r i t i s h Columbia  specimens were taken i n two deep hauls of 249 and 366 meters i n open ocean areas.  32  It i s not suggested that a l l species of chaetognaths which occur i n B r i t i s h Columbia waters have been obtained.  In  the present investigation, S.decipiens i s reported f o r the f i r s t time, and S.planetonis was not taken. undoubtedly  Other species  occur i n the deep oceanic waters and could be c o l -  lected i n offshore hauls.  Also some of these might be carried  into coastal waters from time to time. The following keys were constructed f o r the i d e n t i f i c a tion of specimens collected during t h i s investigation.  It i s  intended that the use of the keys, with the a i d of the descriptions, w i l l enable one to i d e n t i f y the species most commonly found i n the area.  Any specimen that could not be i d e n t i f i e d  would possibly represent a new record.  Because so few species  are involved, d i f f i c u l t s t r u c t u r a l c h a r a c t e r i s t i c s , such as the numbers of teeth, and structure and a r t i c u l a t i o n of parts of the hooks, can be avoided i n the keys.  The f i r s t key i s f o r use  with well preserved individuals with a l l f i n s present, the c h a r a c t e r i s t i c s being obvious enough f o r i d e n t i f i c a t i o n under a binocular microscope only.  In the other key, no use of the  f i n s i s made, but examination with a compound microscope, and perhaps some manipulation, i s necessary f o r counting the hooks.  33  KEYS TO THE SPECIES OP BRITISH COLUMBIA CHAETOGNATHS  FOR  WELL-PRESERVED SPECIMENS  1. One p a i r of l a t e r a l f i n s or two connected pairs 2. No pigment i n the eyes; anal opening at t a i l septum; o i l droplets i n the i n t e s t i n e . . .E. hamata 2. Eyes pigmented; anal opening anterior of t a i l septum; no o i l droplets i n the i n t e s t i n e . . 1. Two  S. l y r a  pairs of l a t e r a l f i n s widely separated 2. Anterior f i n s longer than posterior and almost reaching ventral ganglion; hooks 5-7, usually 6 . . . .  S.  2. Anterior f i n s shorter than posterior and some distance behind ventral ganglion; hooks 8-13, usually 10 . . . . . . . .  FOR  decipiens  S. elegans  SPECIMENS WITH DAMAGED PINS  1. Anal opening anterior of t a i l septum  S.  lyra  2. Anal opening at t a i l septum 2. No pigment i n eyes  E. hamata  2. Eyes pigmented 3. Hooks 5-7  S.  3. Hooks 8-13  decipiens S. elegans  * * «  34 10.  DISTRIBUTION AND FREQUENCY OF OCCURRENCE  The stations studied i n the B r i t i s h Columbia survey were located i h eleven representative areas, as indicated on the map (Map I ) , extending along the entire coast of Canada, from Saanich Inlet i n the south to Dixon Entrance i n the north. The coastl i n e i s characterized by i t s ruggedness, steep shores, s c a r c i t y of beaches, and many deep and long i n l e t s and channels. Numerous r i v e r s of g l a c i a l o r i g i n discharge large enough volumes of fresh water into the sea to have a marked effect upon the fauna and f l o r a of the region. The d i s t r i b u t i o n of the chaetognaths r e f l e c t s both the geographic and oceanographic character of the area. Following i s the d i s t r i b u t i o n of chaetognaths by areas. Area  No. Sta.  Saanich Inlet Indian Arm  No. S.elegans E. hamata S.lyra S.decipiens Hauls  19  19  1456  7(4)  12  837  23  Pendrell Sound  3  3  55  Chan. North Str.of Georgia  3  3  204  1  Bute Inlet  8  26  594  17  Queen Charlotte Strait  19  19  498  8  Queen Charlotte Sound  2  2  342  58  Hecate S t r a i t  9  10  9  1  19  19  2656  836  Masset Sd.& In.  4  4  1847  W. Queen Charl. Islands  20  22  1066  Dixon Entrance  74  3  1+3? 4  6  35  The areas covered i n the survey are l i s t e d i n order from south to north, and the number of stations occupied and number of hauls made are indicated, besides the t o t a l numbers of each species of chaetognath taken i n the region. It i s obvious that S.elegans, the c h a r a c t e r i s t i c species of mixed coastal waters, occurred i n abundance i n most areas, and was present at least i n small numbers i n every region sampled. The oceanic E.hamata was most abundant i n l o c a l i t i e s connected with the open ocean, though a few i n d i v i d u a l s had invaded most of the inland passages and i n l e t s .  No specimens  were taken i n the three i n l e t s , Indian Arm, Pendrell Sound, and Hasset Sound and Inlet.  The mouths of Indian Arm and Masset  Sound are blocked by shallow, warm, water, and the warm temperature and lack of c i r c u l a t i o n i n Pendrell Sound are a barr i e r to other plankton animals as well as to chaetognaths.  As  mentioned previously, few specimens of E.hamata were maturing. Also, no very young ones were taken from the inland waters, and i t appears that, on the whole i n most l o c a l i t i e s , those present may have been migrants carried there by the currents.  Redfield  and Beale (1940) found the same s i t u a t i o n i n the Gulf of Maine, where E.hamata also ranked second i n abundance to S.elegans. They concluded that because E.hamata l i v e s near the surface o f the ocean, i t comes into the Gulf with the currents, where as a terminal migrant from other regions i n which i t breeds endemic a l l y , i t l i v e s as long as circumstances permit and dies without leaving progeny.  36  S.lyra. another species of the deep sea, i s r a r e l y taken near shore.  The s i x specimens obtained were a l l found o f f the  west coast of the Queen Charlotte Islands very near the edge of the continental shelf.  In eastern Canada, Dr. Huntsman found i t s  inner l i m i t was s i x t y miles off the continental shelf i n May  and  June, but that i t was near the edge of the shelf i n July and August.  The B r i t i s h Columbia specimens were taken i n August  within a mile or two of the continental shelf.  However, there  are no data as yet i n western Canada f o r the occurrence of t h i s species during other parts of the year. A less common oceanic form i s S.decipiens. The two regions where i t was  taken are open coast areas, and both of the  hauls were deep, being 249 meters i n Queen Charlotte Sound and 366 meters at the outer end of Dixon Entrance.  At least four  specimens were taken, and i n addition three damaged portions of chaetognaths appeared to be S.decipiens also.  E.hamata was  unusually abundant at the stations where S.decipiens was found, and i t appears that the inner l i m i t s of S.decipiens  overlap  somewhat with the outer l i m i t s of S.elegans and the region of increasing abundance of E.hamata.  11.  DISTRIBUTION IN EACH AREA  The eleven areas sampled are discussed separately, s t a r t i n g with the southernmost and working northward to the region most approaching oceanic conditions off the west coast of the Queen Charlotte Islands.  Maps showing the locations of  37  the stations i n each area, besides tables giving detailed data f o r the hauls are included.  Evident p e c u l i a r i t i e s i n the d i s -  t r i b u t i o n of the animals are pointed out, and  oceanographic  factors possibly influencing the d i s t r i b u t i o n are  suggested.  Fortunately each area i s quite different i n geography and water conditions, a fact which adds to the value of the survey.  I  SAANICH INLET  Map  I I ; Table 1  Saanich Inlet, near the southeastern t i p of Vancouver Island, i s an i n l e t with a wide mouth, bounded by low h i l l s along i t s lower portion, but the upper part, extending into a canyon, i s s i m i l a r to a Norwegian f j o r d .  The i n l e t i s approxi-  mately f i f t e e n miles i n length, and varies i n width from f i v e miles at the widest part to about one mile along Squally Reach i n the canyon.  The greatest depth of 231 meters i s just with-  i n the entrance of Squally Reach.  Because there i s a r e l a -  t i v e l y shallow s i l l at a depth of 62-73 meters at the mouth, the bottom water i s stagnant, being p r a c t i c a l l y devoid of oxygen and reeking with hydrogen s u l f i d e .  Carter (1932) gives 90 meters as  the depth at which the water becomes stagnant both p h y s i c a l l y and chemically.  In 1954  there was p r a c t i c a l l y no oxygen below  75 meters. The water i n the i n l e t i s comparatively warm at the surface, the summer surface temperature ranging between 13.4-15°C, with a sharp drop of two to three degrees three meters below the surface.  The bottom temperature drops another 2-5°C.  The  38  s a l i n i t y i s lower than f o r the P a c i f i c Ocean i n t h i s l a t i t u d e (Sverdrup, et a l , 1952,  give 33.64 °/oo f o r the P a c i f i c Ocean  at 40°N), and i n August i t varies from 29.20 °/oo face to 31.43  °/oo  at the bottom.  at the sur-  A small r i v e r enters the  Inlet at the head and several streams add some fresh water, i f only during the spring freshet, but most of the fresh water probably enters by way of the mouth from Stuart Channel, down which an almost continuously flowing ebb t i d a l current brings fresh water from the huge Eraser River, from various smaller r i v e r s , and the run-off of the abundant r a i n f a l l of the region. The material from Saanich Inlet was collected on May and 22, 1954.  21  Twenty stations were occupied, and most of the  samples collected were examined.  Unfortunately only eleven sta-  tions could be located on the map  (MapH), the data not  been assembled f o r the remaining ones.  having  Most of the eleven sta-  tions are toward the entrance of the Inlet, one being i n the middle, but none at the head.  The Saanich plankton samples  look different from those taken from any other region.  A l l of  them are a bright, clear-green color and almost gelatinous i n consistency, due to the presence of great numbers of f i n e green algae. Because each sample from Saanich was preserved i n two or three b o t t l e s , a method of counting was used f o r most of these stations d i f f e r e n t from that used i n a l l the other areas. For only two of the eleven stations was the entire sample examined.  For the others, one of the bottles was selected at  random and the number of specimens present determined.  This  39 number was then multiplied by two or three, as the case might be, to approximate the probable number of chaetognaths i n the complete sample.  present  Counts were made f o r the entire sample  for the hauls that could not be located geographically. Some i n t e r e s t i n g observations can be made from the data obtained f o r the stations shown on the map.  Along the deeper  mid-channel at stations 1, 3, 5, 8, and 13, S.elegans occurred f a i r l y abundantly, and many specimens were maturing or mature. Out of the 341 estimated specimens caught at these f i v e stations, 171 or 50% were immature, 29 or 9% were maturing and had seminal v e s i c l e s and rod-like ovaries, and 141 or 41$ were f u l l y mature.  At the other stations, immature individuals were abun-  dant, with the exception of the shallow hauls made at stations 6 and 10 i n bays at opposite sides of the i n l e t .  At station 9,  near shore but i n deeper water, a l l stages were f a i r l y abundant. At some of the stations that could not be located, and which were possibly i n the upper part of the Inlet, the population was quite dense, and a large number of mature specimens was present.  Since a l l the maturity stages occurred i n s i g n i f i c a n t  numbers i n Saanich Inlet, one can conclude that the Inlet provides a suitable habitat f o r the species, and that S.elegans i s probably endemic. E.hamata was also present i n the Inlet, though i n small numbers.  Only twenty-three specimens, a l l immature and rather  large (13-17 mm.) were taken i n the deeper hauls.  One must  assume, since there were neither mature specimens nor very small ones, that the ones taken probably found t h e i r way into the i n l e t by way of Stuart Channel and were not indigenous to the i n l e t .  49° 35'  I 2 3° 30' MAP  II.  SAANICH  INLET  - STATIONS  Position Station Channel N  Hauls f Depth Sagitta elegans Eukrohnia hiimata per Sta. in Meters Numbers & Maturity [Size i n mm. Numbers & Maturity Size i n mm. 1  66  Mature 1x3= Immature 10x3=  3 30  3  1  99  Mature Maturing Immature  35 21.5 - 29 15 14 - 20 41 5.5 - 14.5  5  1  155  Mature 41x2= Maturing 1x2= Immature 20x2=  82 2 40  8  1  192  Mature 5x3= Maturing 3x3= Immature 14x3=  15 21.5 - 24 Immature 9 17 - 20.5 42 7-14  1x3= 3  14  13  1  123  Mature Maturing Immature  2x3= 1x3= 6x3=  6 3 18  20 - 20.5 Immature 17.5 7.5 - 13.5  2x3= 6  13 - 15  2  1  80  Maturing 2x2= Immature 43x2=  4 86  13 - 14 4.5 - 16.5  6  1  18  Immature  9x2=  18  4.5 - 7.5  mm  7  1  40  Immature 49x2=  98  4.5 - 12  *m  4  1  42  Immature  75  4-14  •m  10  I  22  Immature  14  4.5 - 8.5  mm  9  1  84  Mature 5x2= Maturing 13x2= Immature 37x2=  S West N  S  East N  S  -  1  Table 1 - SAANICH INLET  7x2=  22.5 4.5 - 13  17 - 26 16.5 5.5 - 14  10 21.5 - 27 14 - 20.5 26 74 6.5 - 15.5  -  -  -  D i s t r i b u t i o n of Chaetognaths (Con. next page)  i  i i  i  P  Not located  Eukrohnia hamata Depth Sagitta elep;ans Position Station Hauls per St a. In Meters Numbers & Maturity Size i n mm. Numbers & Maturity Size i n mm. Immature  4  Mature Maturing Immature  12 24 65  Immature  133  Mature Maturing Immature  28 28 185  Mature Maturing Immature  192  1  1  12  1  14  1  15  1  16  1  -  17  1  -  18  1  19  20  Totals  6-10  —  Immature  2  16  14 - 28.5 12 - 20 6-16  Immature  4  13 - 15  11 11 49  20 - 25 16 - 19 7-14  Immature  4  14 - 16  Mature Maturing Immature  41 6 5  18 - 25.5 18 - 21.5 9.5 - 13.5  Immature  4  15 - 17  139  Mature Maturing Immature  96 6 2  1.5  Immature  3  Mature Maturing Immature  339 134 983  229  Table 1 - SAANICH INLET  20.5 - 26 14-19 7 - 14.5 7-14  20 - 26 17 - 21 16-23 5.5 - 8 ) ) )  1456  mm  •  Immature  23  D i s t r i b u t i o n of Chaetognaths  Cruise 54/l j May 21-22, 1954 ; C.N.A.V. Ehkoli j Nineteen stations, nineteen hauls.  42  II  INDIAM ARM  Map I I I ; Table 2  Indian Arm i s a long, narrow branch of Burrard Inlet, near the c i t y of Vancouver, extending about fourteen miles inland.  At i t s widest point, not f a r from the mouth, i t i s a  mile and a half across, but most of the arm i s only about half a mile wide.  The entrance i s narrow, and l i k e Saanich I n l e t ,  i t has a s i l l  that i s considerably shallower than the average  depth. is  Consequently the bottom waters are stagnant.  The s i l l  only 35 meters deep, and the average depth of the arm, ac-  cording to Carter (1932), i s from 146 to 183 meters, with depths up to 220 meters i n parts where the mountain walls are the most precipitous. The September surface temperature i s very high compared with Saanich i n August, the highest temperature being I9°C at the head.  The surface water gradually cools as i t progresses  toward the mouth, where the temperature was only 15°C.  The-  water i s colder at the bottom, dropping to about 8°C i n the deepest part i n the middle of the Arm. the  surface there i s both a d i s t i n c t  At three meters below  thermocline and h a l o c l i n e .  The temperature drops suddenly four to f i v e degrees, and the s a l i n i t y increases 4-6 °/oo.  The s a l i n i t y varies from  18.06 °/oo at the surface at the head to 28 °/oo i n the deepest water.  At the bottom the water i s even less saline than the  surface water of Saanich.  The low s a l i n i t y r e s u l t s from the  large volume of water poured i n at the head by the Indian River.  43  The material from Indian Arm was c o l l e c t e d on September 4 and 5 i n 1953. There were seven stations i n four areas, twelve hauls being made.  Duplicate stations occupied on two successive  days were located near the entrance, i n the middle, and near the head.  A single station was at the very upper end. S.elegans constitutes the entire chaetognath  population  of Indian Arm, t h i s i n l e t being one of three among a l l the areas sampled where no E.hamata were taken.  The d i s t r i b u t i o n of  S.elegans was especially i n t e r e s t i n g .  In one haul near the  entrance there were no chaetognaths and i n a haul i n the same location the next day there were only three large, immature ones, while halfway up the Arm, S.elegans was both large and abundant and i n a l l maturity stages.  Near the head there were fewer i n d i -  viduals, but more of them were mature. mostly small.  The immature ones were  At the s t a t i o n near the extreme t i p of the Arm,  where the water was only forty-nine meters deep, chaetognaths were completely  absent.  At the location approaching the head, seven hauls i n a l l were made.  The proportions f o r the d i f f e r e n t maturity stages  were about the same i n every haul made.  The average f o r the s i x  hauls at station 174 was 9 mature, 4 maturing, and 43 immature, as compared with the one haul i n the same location at station 172 e a r l i e r i n the day, i n which there were 7 mature, 7 maturing, and 44 immature i n d i v i d u a l s . When c o l l e c t i n g material with v e r t i c a l hauls i t i s impossible to know at what depth the specimens were l i v i n g , but i n the middle of the Arm where the hauls were deepest, as pre-  44  viously stated, S.elegans was both largest and most abundant. It i s known that the larger specimens go into the deeper water. However, great depths may not be a factor, e s p e c i a l l y when the bottom waters are stagnant. Perhaps the length of the l i f e cycle i n combination with the rate of flow of the currents i n the Arm determine at what point the d i f f e r e n t s i z e s and stages w i l l be at any given time.  The surface water flows toward the mouth, and Carter  (1932) states that the progress from the head toward the sea i s slow.  The deep current flowing i n the opposite d i r e c t i o n  would then likewise be slow.  Since there were more mature spe-  cimens at the head than anywhere else, i t may be that as the deep current moves slowly toward the head, the large immature specimens are carried that way, and are ready f o r spawning by the  time they reach the head.  The younger forms l i v e near the  surface (Huntsman,1919) and would travel i n the d i r e c t i o n of the  surface current.  These young individuals may a t t a i n the age  when they seek greater depths by the time they reach the middle of the Arm.  And so the cycle continues, few i n d i v i d u a l s ever  reaching the mouth of the i n l e t .  The c i r c u l a t i o n then would  account f o r the d i s t r i b u t i o n of the indigenous population. The location i n the Inlet of the various maturity stages could also be explained by Meek's (1928) observation that at spawning time S.elegans seeks the more shallow (less saline?) inshore waters, and that the maturing individuals migrate outward into deeper water. The high temperatures from top to bottom i n the shallow  MAP  III.  INDIAN  ARM  - STATIONS  Depth Sagitta ele eahs Position Station Hauls per Sta.i n Meters Numbers & Maturity Size i n mm. Mouth  f  Middle*  r Head '  176  1  70  Immature  3  23 - 25  171  1  209  Mature Maturing Immature  6 4 242  19 - 21 16 - 22 13.5 - 25  175  1  217  Mature » Maturing * Immature *  6+ 3+ 182+  13 - 22 22 - 24 11-26  172  1  78  Mature Maturing Immature  7 7 44  16 - 22 14 - 18 9-22  174  1  86  Mature Maturing Immature  52 21 260  18 - 23 13-18 8-25  Some had been removed. Totals  Table 2 - INDIAN ARM  Mature Maturing Immature  71 35 731  ) ) )  837  D i s t r i b u t i o n of Chaetognaths  Cruise 53/7 j September 4-5, 1953ij C.G.M.V.Cancolim II ; Seven(four) stations, twelve hauls.  47  water toward the mouth, could be a b a r r i e r to the chaetognaths i n the Arm, as well as one preventing the entrance of migrants from the outside, including occasional v i s i t o r s l i k e the oceanic B.hamata.  Polution of the waters near the entrance by sewage  from the c i t y of Vancouver could be another factor.  Ill  PENDRELL SOUND  Map IV; Table 3  Pendrell Sound, seven miles long and one-half to one and a quarter miles wide, almost bisects the westernmost of the two Redonda Islands at the head of the S t r a i t of Georgia.  The depths  to which the v e r t i c a l hauls i n the present survey were made i n d i cate that the bottom slopes gradually from the head to a depth of 347 meters at the mouth.  The surface temperatures were high,  though lower than the maximum i n Indian Arm a month l a t e r .  At  the head of Pendrell, the temperature at the surface was 16.7°C, and i t dropped almost exactly one degree toward the mouth. Unl i k e Indian Arm, there was no thermocline, the temperature decreasing gradually to just over 8°C at the bottom.  The water  was less saline at the surface, but was least saline at the mouth, rather than at the head.  V e r t i c a l l y the s a l i n i t y also  varied gradually from 18.24 °/oo t the surface to 30.80 °/oo at a  the bottom.  There i s no r i v e r discharge into the Sound, the  fresh water supposedly entering by way of Waddington Channel from nearby Toba or Bute Inlets.  An exploratory survey made by the  Institute of Oceanography of the University of B r i t i s h Columbia  48  —s—  I 25°  MAP  IV.  PENDRELL  S O U N D , C H A N N E L S , AND  BUTE  INLET  - STATIONS  Sagitta elet<;ans Position Station Hauls Depth per Sta ,in Meters Numbers & Maturity Size i n mm. 151  1  347  Immature  49  Middle . 154  1  240  Immature  6  Immature  55  Mouth  Total Table 3 - PENDRELL SOUND  11 - 20.5 12-16  D i s t r i b u t i o n of Chaetognaths  Cruise 53/7 j August 24-25, 1953 ; C.G.M.V.Cancolim II j Three stations, three hauls.  Eukrohnia heimata Sagitta elei jans Depth Position Station Hauls per Sta. In Meters Numbers & Maturity sTze i n mm. Numbers & Maturity Size i n mm. SE  150  1  439  Immature  65  SW  149  1  183  Immature  58  147  1  366  Mature Maturing Immature  3 2 76  Mature Maturing Immature  3 2 199  North  Totals  12 - 19.5 10.5 - 23 22-27 19 - 21 9 - 22.5 ) ) )  Table 4 - CHANNELS NORTH END STRAIT OF GEORGIA  204  mm  mm  Immature  1  Immature  1  17  D i s t r i b u t i o n of Chaetognaths  Cruise 53/7 ; August 23, 1953 j C.G.M.V. Cancolim ; Three stations, three hauls.  \  50  in the summer of 1951 also established the fact that there was very l i t t l e c i r c u l a t i o n i n the Sound. Pendrell Sound was one of the three areas where S.elegans was the only chaetognath  present.  However, the d i s -  t r i b u t i o n of t h i s species was unique i n that the population was a l l concentrated toward the entrance, and a l l specimens taken were small and immature, ranging i n size from 11-20.5 millimeters.  The chaetognaths i n the Sound must have entered  at the mouth through random swimming.  Lack of food supply t o -  ward the head may have been a factor i n preventing deeper penet r a t i o n into the Inlet.  Examination  of the specimens during  t h i s survey showed copepods to be an important source of food for chaetognaths,  and i n Pendrell Sound, the copepods are also  concentrated toward the entrance.  IV  (Le Brasseur,1954, unpub;).  CHANNELS NORTH END STRAIT OF GEORGIA Map IV; Table 4  Three hauls were made on August 23, 1953 i n the channels at the north end of the S t r a i t of Georgia off the Redonda Islands and leading to Bute Inlet.  The stations were located at i n t e r -  vals covering a distance of fourteen miles.  One was i n Desola-  tion Sound, o f f the southern shores of the Redonda Islands, another at the entrance of the narrow Lewis Channel, on the west side of the same islands, and the t h i r d i n Calm Channel, off the mouth of Bute Inlet.  The depths of the hauls indicate that the  channels are f a i r l y deep, the deepest haul being made i n Desola-  51  tion Sound at a depth of 439 meters.  The surface temperatures  were a l l higher than those just within Bute Inlet and reach 16.4°C at the entrance of Lewis Channel.  At t h i s station the tempera-  ture decreased gradually from the surface to 8.4°C at the bottom, the s a l i n i t y also increasing gradually, but at the station f a r ther north i n Calm Channel, the surface water was four degrees warmer than i t was at a depth of three meters.  In Desolation  Sound, the warmest water was ten meters below the surface.  The  waters from top to bottom f o r a l l stations were less saline than the open P a c i f i c , increasing from 16.66 °/oo at the surface to 30.90 °/oo at the bottom.  The t i d a l currents i n a l l three loca-  tions are weak (Great B r i t a i n . Hydrographic Office, 1951), and the temperature and s a l i n i t y data do not give evidence of much mixing. At the two southern stations, as i n Pendrell Sound, S.elegans only was found, and though i t was present i n some numbers, a l l individuals were immature.  In Calm Channel, a l l mat-  u r i t y stages of t h i s species occurred, and i n addition one rather large immature E.hamata was taken.  Since both species occur i n  Bute Inlet i n a l l maturity stages, and the water conditions i n Calm Channel are s i m i l a r to those i n Bute, i t i s not surprising to f i n d a similar population just outside the mouth of the Inlet.  52  V  BUTE INLET  Map TV; Table 5  Bute I n l e t , not f a r beyond the northern end of the S t r a i t of Georgia, i s one of the long, narrow, deep i n l e t s c h a r a c t e r i s t i c of the B r i t i s h Columbia coastline.  Only one to  two miles wide, Bute Inlet extends f o r t y - s i x miles inland between mountains that r i s e abruptly 5000-8000 feet to snow-covered peaks.  It i s one of the deeper i n l e t s along the coast, the  deepest haul reaching to 636 meters.  There i s no pronounced  s i l l at the entrance, though the bottom of Calm Channel o f f the mouth, i s over 200 meters above that of Bute just inside the mouth.  There i s at most 41$ less oxygen at 600 meters than  there i s at the surface, and the bottom i s d e f i n i t e l y not stagnant. At the head of the Inlet there are two v a l l e y s , and a large r i v e r of g l a c i a l o r i g i n flows out of each, making the head waters of Bute s i l t y .  A layer of t h i s cold, "milky," water  of low s a l i n i t y ten meters deep flows seaward over a warmer, more saline layer below.  The surface temperatures i n August were from  71-8.5°C i n the upper reaches, while ten meters below the surface, the temperature was around 10°C.  Below the thermocline, the tem-  perature decreased gradually to 8°C at the bottom.  Toward the  middle of the Inlet the thermocline was only three meters below the surface, and the surface had warmed to 10°C with the layer below only just over one degree warmer.  Pickard (1932) states  that seasonal cooling and warming penetrate to about 300 feet  53  (91.4 meters), but that below t h i s depth changes appear to take place slowly and probably  irregularly.  The water at the head of Bute Inlet i s almost fresh. At station 140 i n August, the surface s a l i n i t y was  0.61  °/oo.  Though the surface s a l i n i t y increases as the water flows toward the entrance, i t was only 7.14  °/oo  at the mouth.  meter l e v e l below the surface at station 140, increased sharply to 27.36 °/oo.  At the ten-  the s a l t  content  During the progress of the  water toward the mouth, the difference i n s a l i n i t y of the surface and under layer becomes less pronounced, u n t i l near the mouth there i s a difference of only f i v e parts per thousand. At a l l stations the deep water was between 30 and 31  °/oo.  As the surface water flows out of Bute Inlet the replacement from Calm Channel enters at greater depths.  The cur-  rent i n the deep water then flows toward the head, the d i r e c tion of flow being opposite to that of the surface current. Twenty-six hauls were made at eight stations i n Bute Inlet from August 20 to 23 i n 1953.  These stations were approxi-  mately equidistant along the entire length of the i n l e t .  Both  S.elegans and E.hamata occurred i n a l l maturity stages. S.elegans was abundant only toward the mouth, though almost a l l of the specimens taken were rather small and immature.  In the center  of the Inlet the population was not large, but a few i n d i v i d u a l s were mature or maturing.  Toward the head, though even fewer  specimens were taken, 30% of them were maturing.  Neither  was  E.hamata present i n great numbers, but conditions i n the Inlet appear to be favorable to the extent that most of the few  indi-  54 viduals taken were maturing.  Also, the only f u l l y mature speci-  men obtained throughout the entire survey (Plate II) came from the middle of Bute Inlet.  A l l of the specimens of B.hamata  taken were i n the lower half of the Inlet, and most of these were toward the mouth. The explanation of the d i s t r i b u t i o n of S.elegans i n Bute Inlet might be similar to that f o r the species i n Indian Arm, though the mouth i s not blocked by a shallow s i l l , and the haul i n Calm Channel below the mouth shows that the d i s t r i b u t i o n i s continuous with the outside waters.  Considering the Inlet  only, toward the mouth the animals were immature but not very small and may have reached the stage where they had sought deeper waters.  These specimens then would be at a depth at which  the current would be flowing toward the head.  As they progressed  i n that d i r e c t i o n , they would be maturing, eventually coming near the surface to spawn farther up the i n l e t .  The young then would  be i n the upper waters moving seaward, where they would l a t e r migrate into the deeper water near the mouth. The d i s t r i b u t i o n of E.hamata appears to be quite random. Perhaps migrants entering at the mouth, because conditions are suitable i n the Inlet, are able to mature as they progress up the Inlet with the current i n the deep water.  Since the i n l e t  i s a long one, the time f o r spawning may arrive before they penetrate the waters near the head.  Then when spawning takes place,  the young near the surface are swept out the mouth i n the seaward flowing surface current.  Depth Position Station Hauls Sagitta ele gans Eukrohnia hamata per Sta.i n Meters Numbers & Maturity Size i n mm. Numbers & Maturity Size i n mm. Mouth  Head  146  1  594  Immature  181  20 - 23  Maturing  4  17 - 19  144  5  600  Maturing Immature  1 175  23 12 - 23.5  Maturing Immature  2 6  23 - 27 14 - 17  145  1  636  Immature  13  14 - 20  143  8  600  Mature Maturing Immature  2 4 115  20 - 24 15 18 10 - 21  Mature Maturing Immature  1 2 1  14 13-15 11  142  1  500  Maturing Immature  4 10  18 - 23 12.5 - 18  Immature  1  13  141  1  411  Maturing Immature  2 6  18.5 - 21 13 - 19  139  8  300  Maturing Immature  27 45  16 - 25 10.5 - 18  140  -1  200  Maturing Immature  1 8  21 12.5 - 17  Mature Maturing Immature  2 39 553  Totals  Table 5 - BUTE INLET  ) ) )  594  Mature Maturing Immature  1 8 8  ) ) )  17  D i s t r i b u t i o n of Chaetognaths  Cruise 53/7 j August 20-23, 1953 ; C.G.M.V.Cancollm II j Eight s t a t i o n s , twenty-six hauls.  56  Had the object been only to discover the d i s t r i b u t i o n of S.elegans and E.hamata i n the Inlet, i t would not have been necessary to examine a l l the hauls made at three of the stations where the ship was anchored f o r a long period of time, hauls being made at regular i n t e r v a l s over a period of twentyfour hours.  However, S.planetonis had been reported from the  area, a specimen sent by Mr. Le Brasseur to Dr. Thomson i n A u s t r a l i a having been i d e n t i f i e d as that species.  A very thor-  ough examination of a l l twenty-six hauls f a i l e d to locate another specimen.  It would be rather unusual f o r t h i s deep sea  species to survive a journey into the l e s s saline inland waters, though i n the future, perhaps another specimen could again be taken unexpectedly somewhere i n the B r i t i s h Columbia coastal waters.  VI  QUEEN CHARLOTTE STRAIT Hap V; Table 6  Queen Charlotte S t r a i t , between the northern portion of Vancouver Island and the B r i t i s h Columbia mainland, opens on the oceanic Queen Charlotte Sound.  At the other end i s the  narrow, two and one-half mile wide Johnstone S t r a i t leading to Seymour Narrows, Discovery Pass, and the S t r a i t of Georgia. Queen Charlotte S t r a i t i s sixty-two miles long and twelve to twenty miles wide.  It i s not very deep i n most parts, averag-  ing l e s s than one hundred meters, though at one point near the east end of Nigei Island.not f a r from the entrance there i s a  57  deep of 406 meters.  Another deep of 470 meters i s just within  the entrance of Johnstone S t r a i t . The surface temperature of 8.5-9.7°C i n Queen Charlotte S t r a i t i n June i s about the same as the surface temperature of the P a c i f i c Ocean i n the same l a t i t u d e , and the bottom i s only one to two degrees colder.  The S t r a i t i s s l i g h t l y less saline  than the Ocean, varying from a maximum of 31.63 °/oo at the surface near the entrance to 33.47 °/oo at the bottom.  The  waters are thoroughly mixed by the t i d a l currents, the flood entering from Queen Charlotte Sound and flowing along the southern shores, and the ebb passing out along the northern side. There were nineteen hauls made at nineteen stations i n Queen Charlotte S t r a i t between June 12 and 16 i n 1953.  S.ele-  gans occurred i n every haul, and there was at least one immature E.hamata i n most hauls made i n the channel, though there were none near the coastlines. At the ocean end of the S t r a i t , the specimens of S.elegans taken were small and immature.  A greater number were  taken i n the central part of the S t r a i t and quite a few of these were mature.  The mature ones were both at mid channel and along  the north shore. ture.  Along the south shore the specimens were imma-  It would appear that the animals were maturing i n the  mixed waters of the ebb t i d a l current, while the immature forms are more widely distributed.  As previously stated, other inves-  tigators have found that S.elegans moves shoreward into the more mixed coastal waters to spawn, and the d i s t r i b u t i o n picture i n Queen Charlotte S t r a i t seems to be i n accord with those findings.  Depth Sagitta elegans Eukrohnia hamata Position Station Hauls per Sta.i n Meters Numbers & Maturity Size i n mm. Numbers & Maturity Size i n mm. Mid-chan. W  16  91  Immature  8  13  91  Immature  4  91  Mature Maturing Immature  17 20 28  71  Maturing Immature  15 55  91  Mature Maturing Immature  4 6 23  91  Mature Maturing Immature  7 12 25  3  65  Maturing Immature  4 40  15 - 19 3-14  1  91  Mature Immature  1 8  22 8.5 - 12.5  66  Maturing Immature  9 35  16 - 19 2 - 16.5  8  1  9  E Johnstone Str.  5  1  4  1  2  1  Table 6 - QUEEN CHARLOTTE STRAIT  5.5 - 9  Immature  1  9  Immature  1  7.5  Immature  1  9.5  Immature  1  Immature  3  4 - 8.5 18.5 - 23 15.5 - 19 7-16 15 - 20.5 1-15 18.5 - 25 18 - 19 6.5 - 18 19 - 23.5 14 - 19 1.5 - 14.5  mm  -  D i s t r i b u t i o n of Chaetognaths  ( Con. on next page )  16  9-12  De pt-h Sagitta elejgns Eukrohnia hamata Position Station Hauls per Sta.i n Meters Numbers & Maturity Size i n mm. Numbers & Maturity Size i n mm.  N Shore W  E S Shore W  •J' .  E North Malcolm  15  1  91  Immature  16  14  1  91  Mature Maturing Immature  10 12 27  7  1  91  Mature Maturing Immature  2 1 8  6  1  91  Maturing Immature  1 16  17  1  20  Immature  1  11.5  18  1  71  Immature  4  1 - 13  12  1  91  Mature Immature  1 13  20 6 - 10.5  10  1  91  Immature  18  3-11  11  1  46  Immature  43  1.5 - 13  19  1  10  Immature  4  Mature Maturing Immature  42 80 376  Totals  Table 6 - QUEEN CHARLOTTE STRAIT  2.5 - 12 19 - 22.5 17 - 20 9 - 18.5 23 17 7.5 - 11 16 5 - 15.5  —  -  m  Immature  1  7.5  —  1.5 - 4 ) ) 498 )  Immature  8  D i s t r i b u t i o n of Chaetognaths  Cruise 53/2 j June 12-14,16, 1953 ; C.G.M.V.Cancolim I I ; Nineteen stations, nineteen hauls.  Since the eight specimens of E.hamata taken were small, immature and scattered near mid-channel, i t would seem that they were migrants brought i n by the flood tide.  VII  QUEEN CHARLOTTE SOUND Map VI; Table 7  Queen Charlotte Sound i s the open ocean area between Vancouver Island and the Queen Charlotte Islands. i s Hecate S t r a i t .  At the north  The Sound i s about seventy-five miles long  and up to one hundred and f i f t e e n miles wide.  Since i t i s over  the continental shelf i t i s not extremely deep, the greatest depth recorded i n the 1953 cruise being 400 meters on the ocean side.  The average depth i s probably 150-200 meters l e s s .  The  surface temperature i s rather high compared with Queen Charl o t t e S t r a i t , varying from just over 12°C near the Queen Charl o t t e Islands to a high of 15°C i n the middle, and a lower 11°C near the entrance of the S t r a i t .  There i s a gradual decrease  toward the bottom, and out from shore the bottom temperatureLis about 5.5°C, which i s one to two degrees colder than the bottom waters of the S t r a i t .  The water i s also more s a l i n e , approach-  ing the s a l i n i t y of the open P a c i f i c .  The coastal current pre-  v a i l s and sets northwestward. Only two hauls made i n the region on August 10, 1953 were available f o r examination.  In one shallow haul of 42  meters, just outside the entrance of Queen Charlotte S t r a i t , a swarm of very small immature S.elegans was found.  Few animals  61  131° M A P VI.  QUEEN  C H A R L O T T E S O U N D AND H E C A T E  I28< STRAIT  -  STATION  Sagitta declipi ens Eukrohnia hamata Safj i t t a elegans Depth Position Station Hauls per Sta.in Meters Numbers & Maturity Size i n mm.Numbers & Maturity Size i n mm.Numbers & Maturity Size i n mm. Middle  135  1  249  Maturing Immature  2 139  Coastal  137  1  42  Immature  201  ••I  Maturing Immature  Tota Is  2 340  15 - 22 5.5 - 21  Immature  58  Immature  58  5-16  Maturing  3  Maturing  3  2-13 ) ) 342  Table 7 - QUEEN CHARLOTTE SOUND  D i s t r i b u t i o n of Chaetognaths  Cruise 53/6 ; August 10, 1953 ; C.G.M.V.Cancolim I I ; Two stations, two hauls.  Eukrohnia hamata Sagitta elegans Depth T Position Station Hauls per Sta. In Meters Numbers & Maturity_ Size In mm. Numbers & Maturity_ Size i n mm. East  103  1  36  Immature  2  6.5 - 7  104  1  75  Immature  7  6-25  Immature  9  Totals  Table 8 - HECATE STRAIT  -  Immature  1  Immature  1  D i s t r i b u t i o n of Chaetognaths  Cruise 53/6 ; J u l y 16-30, 1953 ; C.G.M.V.Cancolim II ; Nine stations, ten hauls  17  12 - 12.5  63  that small were taken i n the S t r a i t .  Another swarm of these  very small individuals was encountered at the other station farther off shore, and i n addition, with them were great numbers of equally small E.hamata. In the inshore hauls only larger specimens had been taken, and the population had been scattered and sparse.  S t i l l more i n t e r e s t i n g was the discovery  of three very f i n e , twelve-millimeter specimens of S.decipiens with.well-developed  ovaries, but no seminal v e s i c l e s .  The haul  at 249 meters was not an e s p e c i a l l y deep one, and i t would hardly be expected that a species of the deep ocean at that stage of development would be found there.  Ritter-Zahony (1911b)  gave the range of S.decipiens as 200-1200 meters, the young i n habiting the epiplankton and the mature ones the mesoplankton. With the young of the coastal S.elegans and the oceanic E.hamata both i n abundance, plus the deep sea S.decipiens. the station appears to be approaching the border-line between the oceanic and coastal fauna.  VIII  HECATE STRAIT  Map VI; Table 8  Hecate S t r a i t , between the Queen Charlotte Islands and mainland B r i t i s h Columbia, i s t h i r t y to eighty miles wide and about one hundred and f i f t y miles long.  It i s not very deep,  especially toward the north, where the depth i s at most only 18-36 meters.  I t deepens toward the south to a maximum of  around 183 meters, but the depths are very i r r e g u l a r .  The sur-  face temperature i n July was about 12-13°c, which i s s i m i l a r to  64 the average i n Queen Charlotte Sound, but the bottom temperature of the shallow water usually was only about two degrees colder at most.  The surface s a l i n i t y also was s i m i l a r to that of the  Sound, but there was very l i t t l e increase toward the bottom. T i d a l currents flow into and out of the S t r a i t around both ends of the Queen Charlotte Islands.  The flood currents meeting i n  the middle cause great turbulence and r i p s i n some areas. Toward the northern end of the S t r a i t the t i d a l streams are strong, but the southern end i s so wide that the t i d a l streams are quite weak, except close to the coast of the Queen Charlotte Islands. Ten hauls were made at nine stations i n various parts of Hecate S t r a i t from July 16 to 30 i n 1953, but i n only two hauls were chaetognaths present. At two stations on the east side near the northern entrance, ten specimens, a l l immature, were taken. Nine of these were S.elegans and one was E.hamata. It i s not surprising to f i n d the chaetognath population sparse and almost wanting i n such a shallow, warm area.  At s t a -  tions 103 and 104, where the only specimens were found, the bottom temperatures of 9.5 and 8.4°C were lower than at most of the other stations.  E.hamata was at the station where the bottom  was both deepest and coldest.  65  IX  DIXON ENTRANCE  Map VII; Table 9  Dixon Entrance l i e s between Graham Island of the Queen Charlottes on the south and the Alaskan islands of D a l l and Prince of Wales on the north.  At the eastern end i s Chatham Sound.  The Entrance i s about eighty-six miles long and t h i r t y - f i v e to f o r t y - s i x miles wide.  Along the Canadian shore i t i s not very  deep, but i n the channel there are depths of over 183 meters. The surface temperature between the channel and Graham Island varies from 11.8-13°C, and the bottom temperature of 5.5°C i n the channel i s f i v e to s i x degrees colder than i t i s near the coast.  The water i s s l i g h t l y more saline than i t i s i n Queen  Charlotte S t r a i t , but not as s a l i n e as the open P a c i f i c .  The  t i d a l streams i n Dixon Entrance are somewhat i r r e g u l a r , and the passage i s considered dangerous to navigation (Canada. Hydrographic and Map Service, 1945). Nineteen hauls were made at nineteen stations i n Dixon Entrance between July 19 and 29 i n 1953.  Five stations were  about equidistant along the southern edge of the channel, and others were i n various locations between the channel and the shores of Graham Island.  The two westernmost of the channel  hauls were deep ones made i n the channel i t s e l f , and the other three were not f a r from the edge of i t .  Both S.elegans and  E.hamata were found i n large numbers i n these channel hauls. Examination of Table 9 shows c l e a r l y that at the seaward end of the Entrance, both species were very abundant, and that there  66  were quite a number of mature i n d i v i d u a l s .  However, with pro-  gression eastward toward the mainland, both the population dens i t y and the number of mature animals decreases.  At station 82  more specimens of S.elegans were taken than i n any other l o c a l i t y i n B r i t i s h Columbia. large numbers.  E.hamata was also present i n unusually  Then at station 83, the number of S.elegans dim-  inished, and there were s t i l l more E.hamata.  In fact there were  more E.hamata than S.elegans. reversing the proportion of the species found i n most hauls. E.hamata were maturing.  two  Also some of the specimens of  Another unusual thing about t h i s haul  was the presence of an excellent fourteen-millimeter specimen of the deep sea S.decipiens. besides three doubtful portions of t h i s species.  The undamaged specimen had well-developed  but no seminal  vesicles.  ovaries,  The continental shelf i s very close to the west coast of the Queen Charlotte Islands, and the evidence of these hauls i n Dixon Entrance points to the conclusion that the region of the continental shelf may  form the outer l i m i t f o r S.elegans and  mark the inner boundary of the region most favorable to the oceanic forms.  At station 86, i n a haul made i n the open waters  just outside Dixon Entrance, E.hamata only was found.  This s t a -  tion could be beyond the l i m i t s of S.elegans. The other hauls i n Dixon Entrance were of i n t e r e s t , also, i n the study of the d i s t r i b u t i o n of the chaetognaths i n the strait.  The number of specimens decreased  with distance from  the channel and approach toward shore, and those that occurred were a l l immature.  Along the coast, no chaetognaths were taken  ^ DALL  —  O  PRINCE  OF  WALES  1 SLAN  ISLAND  S4«  00,3 °86 ^ 940 V  0  o82  ^  oBI  J ^ ^ *  "96 7  ° 9 7  B  O  08 090 \  GRAHAM  • >  O  -88 ^-v  0 54"  o7l  o92  ISLAND  y^iiC M A P VII.  \  /  ^S^-^-—  _ DIXON  10  E N T R A N C E - STATIONS  lOO  Position Station Hauls Sagitta elegans Depths Eukrohnia hamata Sagitta deci pi ens per Sta. in Meters Numbers & Maturity Size i n mm.Numbers & Maturity Size i n mm. Numbers & Maturity Size i n mm. Channel ¥  .4' E (  Near ; Channel] Shore-J ward j Coastal Ent.  83  1  366  Mature Maturing Immature  5 3 270  12 - 25 22 - 25 4.5 - 35  Maturing Immature  7 390  14 - 17 5-24  82  1  209  Mature Maturing Immature  10 4 1344  22 - 26 16 - 27 6-26  Immature  293  5-20  81  1  135  Mature Maturing Immature  4 23 - 25.5 Immature : 3 _ 17 - 23 481 2.5-27  88  4 - 18.5  71  1  128  Mature Immature  3 322  23 - 26.5 Immature 4.5 - 26  31  5 - 17  - .  100  1  91  Mature Immature  2 47  Immature  6  7 - 14  -  97  1  65  Immature  43  7-23  Immature  12  80  1  110  Immature  113  4-14  Immature  7  6-12  96  1  46  Immature  1  16  mm  72  1  54  Immature  1  8  mm  86  1  91  Immature  2  13 - 14  Maturing Immature  7 829  Mature Maturing Immature Table 9 - DIXON ENTRANCE  24 10 2622  21 - 25 3.5 - 27  ) ) )  2656  D i s t r i b u t i o n of Chaetognaths  6 - 14.5  ) )  836  Maturing 1 Doubtful por. 3  14  -  . -  mm  VP  Maturing 1 ) Doubtful por. 3 ) 4  (Stations with chaetognaths present).  Cruise 53/6 ; July 19-30, 1953 ; C.G.M.V.Cancolim I I ; Nineteen stations, nineteen hauls.  0 0  69  i n the nine hauls made.  These hauls were i n shallow water, but  i n other parts of B r i t i s h Columbia, equally shallow hauls d i s closed large populations of chaetognaths.  An examination of the  data f o r the temperatures of a l l the stations i n Dixon entrance, leads to the conclusion that i n t h i s part of the world chaetognaths do not occur where temperatures are r e l a t i v e l y high. None occurred where the bottom temperature was much over 9°C. They were most abundant where the bottom temperature was 5.5 C, &  and as the temperature increased, the numbers of chaetognaths decreased. In Hecate S t r a i t , where many hauls were made without finding chaetognaths, the bottom temperatures were also high. A few were taken where the bottom temperature dropped to 8.4-9.5°C.  X  MASSET SOUND AND INLET Map VIII; Table 10  Graham Island, the northernmost and largest of the Queen Charlotte Islands, i s divided almost i n two by Masset Sound and Inlet extending forty-three miles inland from Dixon Entrance. Both the Sound and Inlet are shallow and bordered by f l a t country and low h i l l s .  The entrance to Masset Harbor from Dixon Entrance  i s blocked by two sand bars which are covered by only f i v e and one-half and four and one-half meters of water.  The Sound i s  twenty-two miles long and only one-half to one mile wide.  The  average depth of the channel i s from eighteen to thirty-seven meters, though i n some places i t i s only thirteen meters deep.  70  There are a few deeper places, one near the entrance of Masset Inlet being 238 meters.  Because only one station was located i n  the Sound, there i s l i t t l e information as to the temperature and salinity.  At this one station near the entrance, the temperature  was about 12.5°C and the s a l i n i t y low at 27.5-28 °/oo. The t i d a l streams are strong i n t h i s long, narrow body of water. Masset Inlet, running more or less east and west, i s twenty-one miles long by three to seven miles wide.  The eastern  end i s almost completely occupied by shoals with depths of only one to f i v e and one-half meters.  However the western end i s  deeper, and a depth of 101 meters i s reached near station 89. The water i s warm i n most of the Inlet, the surface temperature in July being around 14.5°C.  The bottom temperature varies with  depth, but i n the deepest parts i s approximately 8.5°C.  There  is a colder layer of water below the surface i n some places, and under that, at between ten to twenty meters, a layer as warm or warmer than the surface.  Below that l e v e l the temperature  decreases gradually and regularly.  Fresh water flows into the  Inlet from several small r i v e r s , besides the A i n , which drains three lakes, and the s a l i n i t y i s low.  The surface s a l i n i t y i s  not as low as i n Indian Arm, Bute Inlet, or Pendrell Sound, but the bottom s a l i n i t y of 22.4-23.25 °/oo i s the lowest encountered in any region studied i n the survey. t i d a l currents are strong.  As i n Masset Sound the  The water i s very well oxygenated,  as there i s not less than 11% oxygen i n the deepest places and up to 96$ at the bottom i n the shallower ones. The material from four stations collected between July 20 and 25, 1953 was available f o r examination.  One station was i n  71 Masset Sound, and three were i n widely separated regions i n Masset  Inlet. No chaetognaths were taken a t the single s t a t i o n near  the entrance of Masset Sound where the depth was only f i f t e e n meters.  This does not mean that none was present anywhere i n  the Sound, but since chaetognaths were also absent along the coastal waters of Dixon Entrance, one may conclude that i n July, there probably were no chaetognaths i n the shallow, warm parts of the Sound. In Masset Inlet S.elegans only was present, but i t occurred i n great abundance and i n a l l sizes and maturity stages. Off the shoals at the eastern side a swarm of extremely small individuals was encountered,  i n the one haul there were 1201  specimens, mostly much under f i v e millimeters i n length.  On  the northern side of the Inlet, s l i g h t l y larger specimens were f a i r l y abundant, while at s t a t i o n 89, near the deepest part, there were hundreds of very large, opaque i n d i v i d u a l s .  Fifty-  seven percent of these animals measured over 20 millimeters, and more were close to 30 millimeters than to 20.  Fifty-five  of the 490 specimens taken i n the one haul were mature and four others were maturing.  For average size these were the largest  specimens of S.elegans taken anywhere, though there were a few almost as large i n Saanich Inlet, and one extra large i n d i v i dual i n Dixon Entrance measured t h i r t y - f i v e millimeters.  Nine  hauls were made at this same Masset station at three-hour i n t e r vals over a period of twenty-four hours.  In only one were  the specimens counted, but the other samples were inspected  72 and found to contain approximately the same number of very large, opaque specimens as the sample counted, i n d i c a t i n g that the large S.elegans were residents i n the area and not a passing swarm. The abundance of S.elegans i n Masset Sound poses several problems.  Evidently the very young of the species are not  repelled by high temperatures, since they were present i n unusually large numbers where the temperature ranged from 14.6°C at the surface to 12.3°C at the bottom.  Neither i s cold water  a barrier to the very small ones, since a large number of them were also found i n Queen Charlotte Sound where the temperature ranged between 11°C to 8°C from top to bottom.  The high oxygen  content of the water i n Masset may offset seemingly unfavorable high temperatures.  However, Davis (1950) found that i n F l o r i d a  waters immature specimens of Sagitta were sometimes obtained i n places where one would never f i n d adults.  He thought that i t  was probable that the eggs had been carried by currents to less favorable regions, where the young are either k i l l e d i n time or are retarded i n t h e i r  development.  The opaqueness and size of the large individuals at station 89 would suggest that they were a colder water form of S.elegans, but the temperature at the bottom i n July was around 8.5°C, corresponding to the highest bottom temperature i n places where only a few stragglers occurred i n Dixon Entrance.  Perhaps  S.elegans i s tolerant of the warm temperatures during part of the year, i n cases where i t i s impossible to move to colder regions.  E.hamata i s completely absent from the warmer regions.  73  132* 3 0 '  MAP  VIII.  MASSET  SOUND  AND  INLET  -  STATIONS  Position Station Hauls Depth Sagitta elej'ans per Sta. i n Meters Numbers & Maturity Size i n mm. Inlet E  w  78  1  34  Immature  1201  75  1  30  Immature  156  3-17  89  1  75  Mature Maturing Immature  55 4 431  21 - 30 23 - 30 2-29  Mature Maturing Immature  55 4 1788  Totals  1.5 - 18  ) ) )  1847  Table 10 - MASSET SOUND AND INLET D i s t r i b u t i o n of Chaetognaths (No chaetognaths taken i n Masset Sound). Cruise 53/6 ; July 20-24, 1953 ; C.G.M.V.Cancolim I I ; Pour stations, four  hauls.  75  As i s c l e a r l y shown i n considering the problem of presence and d i s t r i b u t i o n of the chaetognaths i n Masset Inlet, i t i s very d i f f i c u l t , when specimens have been collected at one season only and by v e r t i c a l hauls, even to t r y to suggest poss i b l e reasons f o r the apparent d i s t r i b u t i o n .  XI  WEST COAST QUEEN CHARLOTTE ISLANDS Map  IX; Table 11  The Queen Charlotte Islands are a compact one hundred and f i f t y - f i v e mile long archipelago of islands approximately f i f t y miles off the coast of B r i t i s h Columbia.  The three p r i n -  c i p a l islands are Graham, the largest and northernmost, Moresby i n the center, and much smaller Eunghit at the south.  Two  nar-  row channels separate these islands, Skidegate between Graham and Moresby, and Houston Stewart between Moresby and  Eunghit.  On the east i s Hecate S t r a i t , and t h i r t y - f i v e to f o r t y - s i x miles across Dixon Entrance on the north are the southern i s lands of Alaska.  The edge of the continental shelf i s only one  to two miles off the west coast of the group.  The twenty-two  hauls made along the west coast between August 5 and 9 i n 1953 were mostly located i n the numerous bays and i n l e t s of that deeply serrated coastline, none having been made beyond the continental s h e l f . In most of the bays and i n l e t s there were no gnaths, but Van and Tasu Inlets were exceptions.  chaeto-  In the  one  haul i n Van Inlet, S.elegans was not only exceptionally abundant,  76  though a l l specimens were unusually small, but the proportion of mature and maturing individuals to immatures was much higher than i n any other haul made anywhere i n any of the areas studied. Of the 805 animals obtained, 15$ were^mature, 19$ maturing, and 66$ were immature.  At t h i s s t a t i o n there was a wide range of  temperature from a high of 15°C at the surface to 7°C at the bottom.  The water was somewhat less saline than the surface  waters of the open P a c i f i c . Similar oceanographic conditions prevailed i n Tasu Inlet, where f i v e stations were occupied.  S.elegans was again abun-  dant , though fewer specimens were taken i n each haul and none was mature.  One small immature E.hamata was also found i n the  inlet. Two off-shore hauls of unusual interest were made at station 114 o f f Skidegate Narrows and at station 132 o f f Cape St. James.  At both of these stations, and also at station 130  i n Houston Stewart Channel, the oceanic S.lyra was found.  The  specimens at 114 and 130 were rather small and immature, but the three taken o f f Cape St. James were larger and two were maturing.  These had rod-like ovaries and some spermatocytes  could be seen i n the t a i l s .  Since t h i s species, l i k e S.decipiens,  i s a deep sea form, i t was not surprising to f i n d S.lyra near the continental s h e l f .  Though Dr. Huntsman found i t i n association  with S.elegans i n one haul only i n eastern Canadian waters, i n a l l three hauls i n which S.lyra was taken i n western waters, S.elegans was also present, as was E.hamata except i n the shallow haul i n Houston Stewart Channel.  Eukrohnia hamata Sagitta e l e ^ans: Sagitta l y r a Depth Position Station Hauls per Sta.i n Meters Numbers & Maturity Size i n mm.Numbers & Maturity Size i n mm. Numbers & Maturity Size i n mm. Port Loals  106  Van Inlet  111  Offshore Skidegatc /  Tasu / Sound  Immature  1  119  Mature Maturing Immature  118 152 535  114  164  Immature  12  121  36  Immature  3  119  175  Maturing Immature  . 11 130  15 - 20 5-18  54  Immature  12  5-12  104  Maturing Immature  2 25  18 - 19 5-18  30  Immature  6  5-8  120  1  !  122  V  Gowgala Bay Flaialngo Inlet Adam Rock Houston Stewart  Off Cape St.James  3.5  26  123  1  125  17 - 23 15 - 19.5 2.-18  5 - 19.5 Immature  Immature  1  6 - 14.5  Immature  2  9.5 - 7  50  Immature  2  13 - 14.5  !  120  Immature  3  8.5 - 13.5  130  !  41  Immature  3  6.5 - 7  132  v  205  Maturing Immature  2 49  18 7.5 - 18  118 + 167 + 781 • 1066  -  9.5  *m  -  -  mm  —  Immature  36  Totals  5  5 - 6.5  !  127  —  mm  1  —  19  —  —  —  Immature Immature  Table 11 - WEST COAST QUEEN CHARLOTTE ISLANDS  67  ;  74  5-17  Immature  1  6.5  Maturing Immature  2 1  25 - 28 20  Maturing 2 + Immat. 4 = 6  D i s t r i b u t i o n of Chaetognaths  Cruise 53/6 j August 5-9, 1953 ; C.G.M.V.Cancolim I I ; Twenty stations, twenty-two hauls.  At station 132 off Cape St. James, where three of the six specimens of S.lyra were obtained, E.hamata surpassed S.elegans i n numbers, as i t did also at the outer channel station i n Dixon Entrance.  This f a c t , along with the absence of  S.elegans from so many of the coastal hauls on the west coast of the Queen Charlotte Islands, and the presence of S.decipiens i n two equally exposed regions, seems to be conclusive  evidence  that the region of the continental shelf i s the outer l i m i t f o r S.elegans i n western Canada, as i t i s elsewhere, and the inner boundary f o r exclusively oceanic forms, as well as the beginning of the region most favorable to E.hamata. which was found only i n small numbers i n the inland areas.  12.  EVALUATION OP THE DATA  The present investigation serves as a basic o v e r - a l l survey of the species of chaetognaths found i n the area and of t h e i r general d i s t r i b u t i o n .  The missing parts of the picture  suggest many i n t e r e s t i n g problems f o r future research.  Ques-  tions about the l i f e h i s t o r i e s , breeding seasons, and abundance at different seasons or from year to year a r i s e .  One also i s  curious as to what f a c t s would appear i f some of the other areas were sampled, including waters beyond the continental shelf. Considering the subject of chaetognaths as i n d i c a t o r s of currents, a l l that can be said at t h i s time i s that a r e l a t i v e abundance of S.elegans along with a few E.hamata indicates  80  mixed coastal waters.  E.hamata i n abundance together with  S.elegans i n diminishing numbers suggests the approach of the outer l i m i t s of the mixed waters.  Should S.lyra or S.decipiens  be obtained, the presence of oceanic water i s indicated.  13.  1.  SUMMARY  A study of the chaetognaths of the coastal waters  of western Canada was made to discover what species were present and to determine t h e i r d i s t r i b u t i o n .  Samples collected during  the summers of 1953 and 1954 by the Institute of Oceanography of the University of B r i t i s h Columbia were available from eleven representative regions along the entire coastline. representing two genera, were found to occur. are:  Four species,  These species  Sagitta elegans, Sagitta l y r a . Sagitta decipiens. and  Eukrohnia hamata. 2.  Sagitta elegans proved to be the most abundant and  widely distributed species, occurring at least i n small numbers in every area sampled.  Its presence indicated mixed coastal  waters, i t s numbers diminishing toward the edge of the continental shelf and i n open areas where oceanic and coastal waters were less mixed.  Oceanographic conditions varied s u f f i c i e n t l y  from area to area to make sub-specific differences apparent i n some populations. 3. Eukrohnia hamata. an oceanic form, also occurring near the surface i n northern regions, had penetrated most areas in small numbers, p r i n c i p a l l y as a migrant carried by the cur-  81  rents.  Warm, shallow water of low s a l i n i t y prevented i t s en-  trance into two i n l e t s , and i t was missing from another where there was l i t t l e c i r c u l a t i o n .  E.hamata was found i n abundance  toward the edge of the continental shelf and i n regions where oceanic influence was predominant. 4 . Sagitta l y r a , a species of the deep sea, was taken i n very small numbers from the waters approaching  the edge of  the continental shelf off the west coast of the Queen Charlotte Islands.  It was r e s t r i c t e d to oceanic waters, and did not occur  in any of the inland channels and i n l e t s . 5, Sagitta decipiens, a deep ocean form, was taken i n two regions where oceanic conditions prevailed.  A few s p e c i -  mens were obtained i n deep hauls made i n Queen Charlotte Sound and at the ocean end of Dixon Entrance.  Both S.elegans and  E.hamata were present i n large numbers i n the hauls, but the stations were not f a r from the outer l i m i t s of S.elegans. and E.hamata was replacing S.elegans as the dominant species.  82  1.4.  ACKNOWLEDGEMENTS  The writer wishes to express grateful appreciation t o : Dr. W.A. Clemens, d i r e c t o r of the Institutes of Oceanography and F i s h e r i e s , and former head of the Department of Zoology* of the University of B r i t i s h Columbia, f o r suggesting the problem, and f o r constant help and encouragement throughout the entire progress of the work and in the preparation of the manuscript. Dr. I.McT. Cowan, professor, and head of the Department of Zoology, f o r h i s active i n t e r e s t i n the work, and espec i a l l y f o r h i s assistance i n the planning of the manus c r i p t and help with the i l l u s t r a t i o n s . Dr. K. Graham, professor of forest entomology, f o r assistance with the microscopy, development of hollow-cone i l l u m ination, and use of s p e c i a l lenses, without which the head armature could not have been seen. Dr. W.S. Hoar, professor of zoology and f i s h e r i e s , f o r advice and help i n the attempt to keep chaetognaths a l i v e i n the laboratory. Dr. P. Ford, assistant professor of zoology, f o r assistance i n staining specimens. Dr. M.D.F. Udvardy, assistant professor of zoology, and Miss Aline Redlick, f o r t r a n s l a t i n g essential German publications.  83  Dr. J.M. Thomson, senior research o f f i c e r , Commonwealth Scient i f i c and Industrial Research Organization of A u s t r a l i a , D i v i s i o n of F i s h e r i e s , f o r helpful correspondence, and f o r examination and corroborative i d e n t i f i c a t i o n of specimens. Dr. R.F. Scagel^ assistant professor of oceanography, f o r h i s generosity i n providing the plankton samples and oceanographic data.  * **  84 LITERATURE CITED  B u r f i e l d , S.T. 1927 Sagitta. Liverpool Mar. B i o l . Comm., Mem. 28: 103 pages, 12 plates. Canada. Hydrographic and Map Service 1945 B r i t i s h Columbia P i l o t (Canadian E d i t i o n ) . V o l . I I , Northern portion of the coast of B r i t i s h Columbia. 2d ed. Ottawa, Hydrographic and Map Service, Surveys and Engineering Branch, Dept. of Mines and Resources: 241 pages. Carter, N.M. 1932 The oceanography of the f i o r d s of southern B r i t i s h Columbia. Prog. Rpts. Pac. B i o l . Sta. and F i s h . Exp. Sta. B i o l . Bd. Canada. (12): 7-11. Clemens, W.A., and Wilby, G.V. 1946 Fishes of the P a c i f i c coast of Canada. F i s h . Res. Bd. Canada. B u l l . 48: 368 pages. Davis, C.C. 1950 Observations of plankton taken i n marine waters of F l o r i d a i n 1947 and 1948. Quart. Jour. F l o r i d a Acad. S c i . 12 (2): 67-103. Dunbar, M.J. 1941 The breeding cycle of Sagitta elegans a r c t i c a A u r i v i l l i u s . Canad; Jour. Res., Sec. D. 19 (9): 258-266. ~~" Fowler, G.H. 1905 Biscayan plankton collected during a cruise of H.M.S. "Research," 1900. Part 3. The Chaetognatha. Trans. Linn. Soc. London. Ser. 2. 10: 55-87, 4 plates. Fraser, J.H. 1937 The d i s t r i b u t i o n of Chaetognatha i n Scottish waters during 1936, with notes on the Scottish indicator species. Jour. Conseil. Perm. Int. Explor. Mer. 12 (3): 311-320. 1949  The occurrence of unusual species of Chaetognatha in Scottish plankton c o l l e c t i o n s . Jour. Mar;.Biol. Assoc. United Kingdom. 28 (2): 489-574.  Great B r i t a i n . Hydrographic Office 1951 B r i t i s h Columbia P i l o t . Vol.I, Southern portion of the coast of B r i t i s h Columbia. 7th ed. London, Hydrographic Dept., Admiralty: 598 pages.  85 Huntsman, A.G. 1919 Some quantitative and q u a l i t a t i v e plankton studies of the eastern Canadian plankton. 3. A special study of the Canadian chaetognaths, their d i s t r i b u t i o n , etc., i n the waters of the eastern coast. Canad. F i s h . Exped., 1914-1915. Dept. Naval Ser., Ottawa: 421485. Kemp, S. 1938  Oceanography and the fluctuations i n the abundance of marine animals. Rpt. Br. Assn. Adv. S c i . , Cambridge, Sect. D-Zool.: 85-101.  Le Brasseur, R.J. 1954 The physical oceanographic factors governing the plankton d i s t r i b u t i o n i n the B r i t i s h Columbia i n l e t s . Master's Thesis, Univ. Br. Columbia (unpub.). Mathews, W.W. 1953 The use of hollow-cone illumination f o r increasing image contrast i n microscopy. Trans. Am. Micr. Soc. 67 (2): 190-195. Meek, A. 1928  On s a g i t t a elegans and Sagitta setosa from the Northumbrian plankton, with a note on a trematode paras i t e . Proc. Zool. Soc. London: 745:776.  Michael, E.L. 1909 Notes on the i d e n t i f i c a t i o n of the Chaetognatha. B i o l . B u l l . 15 (2): 67-84, 1 plate. 1911  C l a s s i f i c a t i o n and v e r t i c a l d i s t r i b u t i o n of the Chaetognatha of the San Diego region. Univ. C a l i f . Pub. Zool. 8: 21-170, 8 plates.  1919  Report on the Chaetognatha c o l l e c t e d by the U.S. f i s h e r i e s steamer "Albatross" during the Philippine expedition, 1907-1910. Smithson. Inst., U.S. Nat. Mus., B u l l . 100. 1 (4): 235-277, 5 plates.  Pickard, G.L. 1953 Oceanography of B r i t i s h Columbia mainland i n l e t s . 1. Water c h a r a c t e r i s t i c s . Prog. Rpts. Pac. Coast. Sta. F i s h . Res. Bd. Canada. (96): 3-6. Quoy, J.R.T., and Gaimard, P. 1827 Observations zoologiques f a i t e s a bord de l'Astrolabe" en Mai 1826, dans l e detroit de G i b r a l t e r . Annales S c i . Nat. 10: 225-239. tt  Redfield, A . C , and Beale, A. 1940 Factors determining the d i s t r i b u t i o n of populations of chaetognaths i n the Gulf of Maine. B i o l . B u l l . 79: 459-489.  86  Ritter-Zahony, R.C. 1911a Revision der Chatognathen. Deutsche Sudpolar Exped. 13 (5): 1-71. 51 f i g s i n text. 1911b Die Chaetognathen der Plankton-Expedition. Plankton Expedition. 2: 1-33. 1911c Chaetognathi. T i e r r e i c h . 29: 1-35. Russell, F.S. 1933 On the biology of Sagitta. IV. Observations on the natural history of"Sagitta elegans V e r r i l l and Sagitta setosa J . Miiller i n the Plymouth area. Jour. Mar. B i o l . Assoc. United Kingdom. 18 (2): 559-574. Sverdrup, H.U., Johnson, M.W., and Plemming, R.H. 1942 The oceans, t h e i r physics, chemistry, and general biology. Prentice-Hall Inc. New York. 1087 pages. Thomson, J.M. 1947 The Chaetognatha of south-eastern A u s t r a l i a . Council Scient. and Indust. Res., A u s t r a l i a , B u l l . 222. Div. of F i s h . (14). Melbourne. 43 pages. Tokioka, T. 1940 The chaetognath fauna of the waters of western Japan. Rec. Oceanog. Works Japan. 12 (1): 1-22. T u l l y , J.P. 1937 Report on dynamic studies off the Canadian P a c i f i c coast, 1936. Trans. Am. Geophys. Union, Eighteenth An. Meet, 1937: 228-231. 1953  Oceanography - science of the sea. Canad. Geog. Jour. Dept. of F i s h . Canada, Ottawa. Reprint 19 pages.  Walcott, C.D. 1911 Cambrian geology and paleontology, I I , Middle Cambrian annelids. Smithson. Msc. C o l l . , B u l l . 2014, 57 (5): 109-144, 6 plates.  -* # *  

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