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Aspects of the life history of Lycodopsis pacifica (Collett) 1879 Levings, Colin D. 1967

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ASPECTS OF THE LIFE HISTORY 0? Lycodopsis p a c i f i c a ( C o l l e t t ) 1879 by C o l i n D. Levings B.Sc. (Hon.), U n i v e r s i t y of B r i t i s h Columbia, 1965 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n the Department of Zoology We accept t h i s t h e s i s as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA October 1967 In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f the r e q u i r e m e n t s f o r an advanced deg ree a t the U n i v e r s i t y o f B r i t i s h C o l u m b i a , ! ag r ee t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and S t u d y . I f u r t h e r ag r ee t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may be g r a n t e d by the Head o f my Depar tment o r by h.iJs r e p r e s e n t a t i v e s . It i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l no t be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . Depar tment o f The U n i v e r s i t y o f B r i t i s h C o l u m b i a Vancouve r 8, Canada Date Orth £ f n<ol~ E R R A T A SHEET P. 9 F i r s t line second paragraph read ''March" for "march 1 P. 22 Fourth line read "viviparous" for "ovoviviparous". P. 29 F i r s t line, f i r s t paragraph - read "12" for "10". P. 67 Thirteenth line read "viviparous" for "ovoviviparous". i ABSTRACT Aspects of the l i f e h i s t o r y of Lycodopsis p a c i f i c a ( C o l -l e t t ) 1879 were studied during the period September 1965 to November 1966. Two areas i n the S t r a i t of Georgia, B r i t i s h Columbia, were i n v e s t i g a t e d . Trawls were used as sampling de-v i c e s . Sexually mature i n d i v i d u a l s were c o l l e c t e d during the per-i o d September to January. Lycodopsis p a c i f i c a has a remarkably small complement of mature eggs (average complement J>O.LL), The mature eggs are l a r g e , w i t h an average diameter of 5.0 mm. Sexual dimorphism i s present. Males s t a r t to grow f a s t e r than females at approximately 170 mm i n length. The older males are' l a r g e r than females. There i s some evidence that parental care i s i n v o l v e d i n the reproductive behaviour of the species. Age was estimated by counting the annular r i n g s on oto-l i t h s . Both males and females ranged up to f i v e years of age. The age-length r e l a t i o n s h i p f o r both sexes i s presented. The length-weight r e l a t i o n s h i p of the species i s described. The food spectrum of Lycodopsis p a c i f i c a was determined. At outer Burrard I n l e t , the species feeds p r i m a r i l y on i n f a u n a l i n v e r t e b r a t e s of the Phyla Mollusca and Annelida, and the Sub-phylum Crustacea, The place of L. p a c i f i c a i n the bottom com-munity i s considered. The anatomy of s t r u c t u r e s associated with feeding are de-sc r i b e d . V i s u a l and "chemical" senses are probably important i n food-getting behaviour. The feeding adaptations and food of the species i s discussed i n r e l a t i o n to sediment type. L. i i p a c i f i c a i s probably not s p e c i a l i z e d to remove i n f a u n a l food items from one type of sediment. I t was assumed that Lycodopsis p a c i f i c a would aggregate where high concentrations of i n f a u n a l organisms s u i t a b l e as food would be found. At outer Burrard I n l e t , high numbers were caught on s e v e r a l sediment types, ranging from s i l t - s a n d to s i l t . At the Cape Lazo area, catches of L, p a c i f i c a were highest on a s i l t sediment. The species i s l i k e l y capable of foraging on a range of sediment types. Some f a c t o r s a f f e c t i n g the infauna are discussed, and the u s e f u l l n e s s of simple mechanical a n a l y s i s of sediments i n benthic ecology i s ques-tioned. i i i ' TABLE OF CONTENTS Page LIST OF TABLES. . v i LIST OF FIGURES . . . .v ACKNOWLEDGEMENTS v i i i INTRODUCTION 1 STUDY AREAS AND METHODS « . . 4 LIFE HISTORY SECTION 11 MORPHOLOGY, FEEDING, AND SEDIMENTS .39 SEDIMENTS AND ABUNDANCE OF Lycodopsis p a c i f i c a .48 SUMMARY . . . 0 . . . . 67 LITERATURE CITED 69 APPENDIX 73 i v LIST OF TABLES Table No. Page I , Outer Burrard I n l e t sampling area i n f o r m a t i o n . . . . . . 4 I I . Cape Lazo g u l l y sampling area i n f o r m a t i o n , . . . . . . . 8 I I I * P e r t i n e n t dimensions of t r a w l s employed at the two study areas , 8 IV. Catches of L, p a c i f i c a per ten minute t r a w l at the outer Burrard I n l e t experimental area, . . . . . . .51 V. Catches of L. p a c i f i c a per ten minute t r a w l at the Cape Lazo g u l l y , , , 52 VI. A n a l y s i s of variance of catch data at the outer Burrard I n l e t experimental area. . , . , , . .54 V I I . Tests of s i g n i f i c a n t d i f f e r e n c e s betv/een catches o f L« p a c i f i c a at outer Burrard I n l e t transect s t a t i o n s . « < . « « « . « . , , . « , « • , . , « . . «56 Appendix I. Age-length table of male L. p a c i f i c a c o l l e c t e d at the outer Burrard I n l e t study area , . « . . . . . . . ,75 I I , Age-length table of female L. p a c i f i c a c o l l e c t e d at the outer Burrard I n l e t study area .76 V LIST OF FIGURES Figure No. Page 1. Sampling l o c a t i o n s , transect patterns, and bathymetry at the outer Burrard I n l e t study area. . . . 5 2. Sections patterns and bathymetry at the Cape Lazo study area 7 3« T o t a l l e n g t h of L, p a c i f i c a p l o t t e d against the r a t i o of m a x i l l a r y length to t o t a l l e n g t h . . . . . . .14 k. Annual v a r i a t i o n i n average surface area (mm ) of one t e s t i s lobe of L. p a c i f i c a . .16 5. Annual v a r i a t i o n i n average complement of three egg s i z e s i n L. p a c i f i c a , .16 6. Histograms showing per cent frequency of mature female L. p a c i f i c a by 10 mm length group , .18 7. Histograms showing per cent frequency of mature male L. p a c i f i c a by 10 mm length group 18 8. Length frequency polygons of L, p a c i f i c a captured at the Cape Lazo g u l l y at three sampling times 20 9. Per cent frequency of empty d i g e s t i v e t r a c t s observed i n samples of L. p a c i f i c a December 1965 -November 1966 • • • • . * . * « . « . . * . « • • • ' • .21 10. Photograph of male and female L. p a c i f i c a on the ocean floor.;. • 23 11. Age l e n g t h r e l a t i o n s h i p of L. p a c i f i c a based on mean le n g t h at age data 25 12. Length-weight r e l a t i o n s h i p of L. p a c i f i c a . . . . . . .27 v i Figure No, Page 13. Per cent abundance by number of food items of L, p a c i f i c a . Data from 20 f i s h per time period c o l l e c t e d at outer Burrard I n l e t 30 14. Average per cent abundance by number of food items . . ,31 15» Histograms showing seasonal d i f f e r e n c e s i n the food spectrum of L. p a c i f i c a , ,33 16, Histograms showing s p a t i a l d i f f e r e n c e s i n the food spectrum' of L. p a c i f i c a ,35 17, Histograms of per cent abundance by number of various food items of L, p a c i f i c a over the i n d i c a t e d l e n g t h range , , . .36 18, A n t e r i o r view of the buccal region of L. p a c i f i c a (Xl£).41 19, L a t e r a l views of the buccal region of L. p a c i f i c a (XI) .42 20, Dorsal view of the b r a i n and c r a n i a l nerves of L. p a c i f i c a (X3) . .45 21, Catches of L. p a c i f i c a at outer Burrard I n l e t r e l a t e d to sediment type .57 22, Catches of L. p a c i f i c a at outer Burrard I n l e t \ ( | r e l a t e d to sampling depth 57 23, Catches of L„ p a c i f i c a at the Cape Lazo g u l l y . . . . . .59 24, Catches of L. p a c i f i c a at the Cape Lazo g u l l y r e l a t e d to sediment type . . . . . . . . . . . . . . . . 6 0 25, Catches of L. p a c i f i c a at the Cape ,Lazo g u l l y r e l a t e d to sampling depth 60 26, Length frequencies of L. p a c i f i c a captured at two s t a -t i o n s at the outer Burrard I n l e t experimental study area, 63 v i i Appendix Figure No. Page 1. Per cent frequency of L. p a c i f i c a o t o l i t h s with an opaque edge during the period November 1965 -November 1 9 6 6 . . . . . . . . . . c . . «77 v i i i ACKNOWLEDGEMENTS The cooperation and as s i s t a n c e of many persons i n t e r e s t e d i n marine e c o l o g i c a l research made t h i s study f e a s i b l e , Messrs, K, Tanaka and J. Kondo, commercial shrimp fishermen, k i n d l y helped c o l l e c t i n outer Burrard I n l e t , Mr, T, H, B u t l e r , Crustacea I n v e s t i g a t i o n , F i s h e r i e s Research Board of Canada, B i o l o g i c a l S t a t i o n , Nanaimo, B.C., provided accomodation on the R/V. " I n v e s t i g a t o r No, 1" f o r s t u d i e s at the Cape Lazo g u l l y . Dr. R, Sheldon, A t l a n t i c Oceanographic Group, F i s h e r i e s Re-search Board of Canada, Dartmouth, N.S,, provided data on the sediments at t h i s s i t e . The encouragement and i n s p i r a t i o n of Mr, B u t l e r and Dr. Sheldon i s g r e a t l y appreciated, Dr. J . Murray and other members of the Ge o l o g i c a l Oceanography group, I n s t i t u t e of Oceanography, U n i v e r s i t y of B.C., Vancouver, B.C., provided l a b space, sediment sampling equipment, and advice on sediment a n a l y s i s . Dr. J\T, J . Wilimovsky and the I n s t i t u t e of F i s h e r i e s , U n i v e r s i t y of B.C., Vancouver, B.C., provided f i n a n -c i a l a s s i s t a n c e i n the operation of the I n s t i t u t e v e s s e l , Messrs, P, Young, D. Hay, and s e v e r a l members of the I n s t i t u t e of F i s h e r i e s a s s i s t e d i n f i e l d work. Dr. E, W, Fager, Scripps I n s t i t u t e of Oceanography, La J o l l a , C a l i f o r n i a , k i n d l y allowed use of the photograph of Lycodopsis p a c i f i c a taken from a sub-mersible. Mr e S. Gopaul d i d the drawings of the feeding ana-tomy of the species, Dr„ I . McT Cowan, Dean of the Faculty of Graduate Studies, U n i v e r s i t y of B.C., i d e n t i f i e d several species of molluscs found i n food s t u d i e s . Drs. N. J , Wilimovsky, J . E, P h i l l i p s , B. Bary, and I , E. E f f o r d read the manuscript i x and o f f e r e d u s e f u l c r i t i c i s m s . The help o f . a l l persons connected with the study i s most g r a t e f u l l y acknowledged. 1 INTRODUCTION Members of the Family Zoarcidae are found i n very diverse h a b i t a t s , ranging from the bathypelagic regions (Melanostigma  pammelas) ( M a r s h a l l , 1954) to the i n t e r t i d a l zone (Commandorella  popovi)(Andriashev, 1937)« Most z o a r c i d s , however, are bottom dewl l e r s of. polar and temperate seas. Lycodopsis p a c i f i c a ( C o l l e t t ) 1879 i s a bottom d w e l l i n g z o a r c i d which ranges from southern C a l i f o r n i a to the Alaskan coast. At se v e r a l l o c a t i o n s i n the S t r a i t of Georgia, B r i t i s h ^ Columbia, the species i s captured when t r a w l i n g f o r commercial shrimp (Pandalus spp.). In Smith I n l e t , o f f Queen C h a r l o t t e Sound, the species i s a l s o very abundant, and B a y l i f f (MS, 1954) notes "the species i s common i n Puget Sound. Lycodopsis p a c i f i c a i s r a r e l y taken i n t r a w l i n g operations on the outer c o n t i n e n t a l s h e l f of B r i t i s h Columbia but i s dominant i n the bottom f i s h fauna of some c o a s t a l i n l e t s . The f i r s t s e c t i o n of the present study deals w i t h the gen-e r a l biology of Lycodopsis p a c i f i c a . In the second s e c t i o n , L, p a c i f i c a i s used to study feeding adaptations of the bottom f i s h f o r existence on sediments. The r e s u l t s of t r a w l i n g f o r the species on s e v e r a l bottom types are presented. Two questions were asked: (1) Do the feeding adaptations o f Lycodopsis p a c i f i c a r e s t r i c t the species to c e r t a i n sediments? (2) On what type of sediment i s the species found most abun-dantly? Sediment c h a r a c t e r i s t i c s may play an important r o l e i n governing the (short-term) d i s t r i b u t i o n and abundance of bottom f i s h e s p a r t i c u l a r l y i f t h e i r food spectra l a r g e l y i n v o l v e s 2 s e s s i l e organisms. The bottom type may influence the faunistic complexes of invertebrates. 3 STUDY AREAS AND METHODS Outer Burrard I n l e t Outer Burrard I n l e t i s the seaward (western) enlargement of a c o a s t a l f j o r d , Burrard I n l e t , on the southern B r i t i s h Columbia coast ( l o c a t e d about Zf9°l8' N, Long. 123°12» W). The i n l e t i s bordered on the north by Howe Sound, on the f a r west by the S t r a i t of Georgia, and the southwest by the northern arm of the • Fraser R i v e r ( F i g . 1 ) , Through the cooperation of commercial shrimp fishermen, lk samples over the period September 1965-November 1966 were ob-tained from outer Burrard I n l e t , Samples c o l l e c t e d using a small experimental t r a w l towed by the I n s t i t u t e launch supplemented these samples (Table I ) . The sediments of southwest outer Burrard I n l e t were studied i n some d e t a i l i n May and June 1 9 6 6 . This l o c a l i t y w i l l be termed the experimental study area of outer Burrard I n l e t . Three t r a n s e c t s were chosen f o r experimental sampling. These are termed Spanish Banks, P o i n t Grey and North Arm t r a n s e c t s ( F i g , 1 ) . The Cape Lazo g u l l y was sampled through the cooperation of the Crustacea I n v e s t i g a t i o n , F i s h e r i e s Research Board of Canada, B i o l o g i c a l S t a t i o n , Nanaimo, B.C. The g u l l y i s l o c a t e d on the c e n t r a l east coast of Vancouver I s l a n d , I t i s a deep trough (50 fm, 91.0m) approximately 8 miles (14«8 km) long and 2 miles ( 3 2 km) wide. I t i s bordered on the northwest by Cape Lazo (Lat. -+9°37' N, Long. 1 2 4 ° 4 8 ' W). A s i l l r i s i n g to w i t h i n 15 fm ( 2 7 . 4 m) of the surface separates the 4 Table I . Outer Burrard I n l e t Sampling Area Information SAMPLE AREA OF FISHING DATE NO. OR TRANSECT SOURCE Dec. 3 1965 1 West Vancouver Comm. shrimp vessel Jan. 9 1966 2 West Vancouver Comm. shrimp ve s s e l Jan. 31 1966 3 Fraser D e l t a Comm. shrimp v e s s e l Feb. 14 1966 4 J e r i c h o Comm. shrimp ve s s e l March 6 1966 5 West Vancouver Comm. shrimp vessel March 21 1966 6 West Vancouver Comm. shrimp v e s s e l A p r i l 10 1966 7 Gibsons Comm. shrimp v e s s e l May 4 1966 8 West Vancouver Comm, shrimp vessel June 10 1966 9 Spanish Banks Experimental t r a w l i n g J u l y 4 1966 10 West Vancouver Comm, shrimp vessel J u l y 21 1966 11 West Vancouver Comm. shrimp vessel Aug. 8 1966 12 Spanish Banks Experimental t r a w l i n g Aug, 21 1966 13 West Vancouver Comm. shrimp v e s s e l Sept, 8 1966 14 Spanish Banks Experimental t r a w l i n g Sept. 24 1966 15 West Vancouver Comm. shrimp ve s s e l Oct, 12 1966 16 West Vancouver Comm, shrimp ve s s e l Nov. 13 1966 17 West Vancouver Comm, shrimp v e s s e l See Figure 1 f o r l o c a t i o n of f i s h i n g areas and t r a n s e c t s . 5 l5^&j7™£nB' t r a n S 6 C t S ' b a t h ^ e t ^ a t t h e ««ter 6 trough from the depths of the S t r a i t of Georgia ( F i g . 2 ) . On the west the g u l l y i s bordered by Denman Is l a n d and on the south by Hornby I s l a n d . The g u l l y was d i v i d e d i n t o nine s e c t i o n s that crossed i t i n an east-west d i r e c t i o n . As the bottom was more s u i t a b l e f o r t r a w l i n g on the west slope of the g u l l y , most c o l -l e c t i o n s were made on the western ends of the s e c t i o n s . The g u l l y was sampled i n November 1965} January 1966, August-September 1966 and March 1967 (Table I I ) . Data obtained from these samples were employed p r i m a r i l y i n i n v e s t i g a t i o n s of the r e l a t i o n s h i p of Lycodopsis p a c i f i c a to sediment type. D e s c r i p t i o n of Sampling Equipment and L i m i t a t i o n s of Sampling Samples obtained from commercial shrimp fishermen were from catches taken with a modified beam t r a w l . A l l other f i s h e s examined from both study areas were captured with o t t e r t r a w l s . Table I I I shows the p e r t i n e n t dimensions of sampling equipment. Of primary importance was the mesh s i z e i n the codend of the t r a w l . This introduced s e r i o u s sampling b i a s i n some catches. Mesh s e l e c t i o n i s of importance when sampling f i s h popula-t i o n s ; i f only one f i s h i n g method (or mesh s i z e ) i s employed, i t w i l l very l i k e l y provide an unrepresentative sample (Packer, 1958). P a r r i s h (1958) p o i n t s out that i n a d d i t i o n to mesh s i z e , s e l e c t i v i t y i s a f f e c t e d by several f a c t o r s , the most important of which are: (a) method of r i g g i n g the cover (chafing gear), (b) catch s i z e , (c) towing speed, (d) towing time, (e) net ma-t e r i a l , and ( f ) amount of escapement through d i f f e r e n t p a r t s of 7 8 Table I I . Information on the Cape Lazo study area DATE November 2 1965 January 22-23 1966 August 2if-September 1 1966 March 18 1967 SECTIONS OCCUPIED* 2 - 7 4 - 7 1 - 7 1 - 3 TOTAL NUMBER TRAWLS SAMPLED 10 14 60 11 *See Figure 2 f o r l o c a t i o n of sections, Table I I I . P e r t i n e n t dimensions of t r a w l s employed at the two study areas. Area and Vessels Employed  Cape Lazo G u l l y : " I n v e s t i g a t o r No. 1" Outer Burrard In-l e t : v a r i o u s commercial shrimp v e s s e l s Outer Burrard I n -l e t : I n s t i t u t e of F i s h e r i e s v e s s e l Length of Footrope 47.3 f t . (14.2 m) 43.0 f t . (12.9 m) 12.0 f t . (3.6 m) Mesh Size i n Body and Wing 1.5 i n , (3.8 cm) 1.3 i n . (3.2 cm) 1.0 i n , (2.5 cm) Mesh Size i n Codend 1.5 i n . (3.8 cm) 1.3 i n . (3.2 cm) 1,0 i n , (2,5 cm) Mesh Size of L i n e r 0.5 i n . (1.3 cm) None 0.5 i n . (1.3 cm) 9 the net and codend. A d e t a i l e d study of mesh s e l e c t i v i t y i s be-yond the scope of t h i s work. Aquarium Methods Lycodopsis p a c i f i c a was maintained i n aquaria on two occa-s i o n s , o In march 1966 seven Lycodopsis p a c i f i c a from outer Burrard I n l e t were maintained approximately one month i n a f i v e g a l l o n (18.9 1) aquarium. Sea water of s a l i n i t y 27%;-was cooled by run-ning tap water i n g l a s s tubing; a temperature range of 10-11°C was maintained. The seawater was c i r c u l a t e d and aerated by an a i r - d r i v e n f i l t e r system. Sediment was obtained at Inner E n g l i s h Bay at a depth of 10 fm (18.3 m) and placed i n the tank. The sediment was almost c o n t i n u a l l y i n suspension and could be de-s c r i b e d as " s i l t y - m u d " . On December 27 1966, 61 i n d i v i d u a l s were obtained from outer Burrard I n l e t . These were maintained i n a 180 g a l l o n (683 1) wooden tank w i t h p l e x i g l a s viewports. M a t e r i a l c o l l e c t e d at ex-treme low t i d e inshore of the Spanish Banks transect served as substrate; i t was r e l a t i v e l y coarse and s e t t l e d r a p i d l y . P r e s e r v a t i o n and Measurements A f t e r capture, f r e s h specimens of Lycodopsis p a c i f i c a were f i x e d i n a s o l u t i o n of 10% formalin f o r a period of approximately 2k hours. They were then immersed i n running f r e s h water f o r three to f i v e hours and f i n a l l y preserved i n kQP/o i s o p r o p y l a l -cohol. 10 Measurements throughout t h i s study were taken from the t i p of the mouth (mouth closed) to the extreme end of the caudal f i n , and are to the nearest m i l l i m e t e r ( t o t a l l e n g t h - P a r r i s h , 1958). Except where noted, a l l measurements were made on pre-served specimens. 11 LIFE HISTOEY SECTION Zoarcidae are b l e n n i o i d f i s h e s c h a r a c t e r i z e d by elongated bodies and long anal and d o r s a l f i n s which are joined to the caudal f i n to form a continuous f i n edging the p o s t e r i o r part of the body. The p e l v i c f i n s , when present, are small and are l o -cated a n t e r i o r to the p e c t o r a l f i n s . Many species of Family Zoarcidae are d i s t r i b u t e d i n the northern part of the P a c i f i c and A t l a n t i c Oceans as w e l l as i n A r c t i c and A n t a r c t i c Seas (Ni k o l s k y , 1961). B a y l i f f (MS, 1954) records p e r t i n e n t references to north-east P a c i f i c z o a r c i d s ; most are of a taxonomic nature. There i s no comprehensive account of the biology of z o a r c i d s i n the north-east P a c i f i c Andriashev (1937) notes observations on zo a r c i d s from the Bering and Chukchi seas. There i s l i t t l e i n f o r m a t i o n on the l i f e h i s t o r y of Lyco-dopsis p a c i f i c a although i t s taxonomy and d i s t r i b u t i o n have been w e l l described,, B a y l i f f ' s recent r e v i s i o n (MS, 1954) of the zoa r c i d s of the northeast P a c i f i c i n c l u d e s a convenient a r t i f i -c i a l key. He records the range of L, p a c i f i c a as being southern C a l i f o r n i a to Afognak I s l a n d , Alaska, The species has been cap-tured over a wide range of depths (5 fm } 9*2 m i n Puget Sound ( B a y l i f f , MS, 1 9 5 4 ) ; 200 fm ( 3 6 0 . 0 m) i n C a l i f o r n i a waters (Clemens and Wilby, 1 9 6 1 ) ) . Some b r i e f observations of the biolog y of L. p a c i f i c a are found i n Clemens and Wilby ( 1 9 6 1 ) . They report the species i s caught most commonly on a mud bottom. 12 Reproduction Data on the reproductive c o n d i t i o n of specimens c o l l e c t e d at outer Burrard I n l e t were c o l l e c t e d over the period December 1965 - November 1966. From each sample, 30 i n d i v i d u a l s , a l l over 100 mm i n length, were studied. Information on sexual dimorphism was obtained from specimens captured at the Cape Lazo g u l l y . Because of mesh s e l e c t i o n , an adequate s i z e s e r i e s of small f i s h was not a v a i l a b l e from outer Burrard I n l e t . Sexual Dimorphism There i s strong sexual dimorphism i n Lycodopsis p a c i f i c a . Growth s t u d i e s (see p. 25) show that at a length of approximately 170 mm males begin to grow f a s t e r than females. The males con-t i n u e t h i s a ccelerated growth and eventually are l a r g e r than females, B a y l i f f (MS, 1954) mentions that e a r l y taxonomists de-s c r i b e d the males and females of Lycodopsis p a c i f i c a as separate species u n t i l 1896 when Jordan and Starks pointed out that the two were merely the sexes of one species. The sexual dimor-phism i s exemplified i n head s i z e , p a r t i c u l a r l y snout length. The l a r g e r males have l a r g e , shovel-shaped snouts; they have been described as " a l l i g a t o r - h e a d s " . The appearance of sex d i f f e r e n c e s i n morphology may be an i n d i c a t i o n of the onset of sexual maturity. Measurements were made on specimens of Lycodopsis p a c i f i c a taken at the Cape Lazo g u l l y i n March 1967 to determine whether males have l a r g e r heads at a l l lengths (and ages). Fresh specimens of 46 females and 62 13; males were s t u d i e d . Snout len g t h was estimated by the length of the m a x i l l a r y (Gregory, 1933). The r a t i o of the m a x i l l a r y length to the t o t a l l e n g t h was determined f o r each i n d i v i d u a l ( F i g . 3 ) . The r e l a t i o n s h i p of m a x i l l a r y length to t o t a l l e n g t h was the same fo r a l l females encountered. In males, the r a t i o of the m a x i l l a r y l e n g t h to the t o t a l l e n g t h remained approximately constant u n t i l about 170 mm. A f t e r t h i s l e n g t h males have longer m a x i l l a r i e s i n r e l a t i o n s h i p to body le n g t h . Males of 170 mm i n l e n g t h and greater were most frequently s e x u a l l y mature i n f a l l and winter at outer Burrard I n l e t (see below). D e s c r i p t i o n of Gonads and C r i t e r i a of Sexual M a t u r i t y  Males The b i l o b e d t e s t e s of Lycodopsis p a c i f i c a l i e i n the pos-t e r o - d o r s a l part of the body c a v i t y . Each lobe of the t e s t i s i s roughly rectangular i n shape. The organs are connected to the g e n i t a l pore by a sperm duct. The t e s t e s are whitish-grey i n colour; t h e i r whiteness seems to be accentuated at sexual ma-t u r i t y . The surface area of a t e s t i s lobe was determined by measur-i n g the l e n g t h and width with d i v i d e r s . I n d i v i d u a l s with lobes of 20 mm or over were considered s e x u a l l y mature because they contained, loose or "running" sperm. Females The ovary of Lycodopsis p a c i f i c a i s a median, unpaired s t r u c t u r e which l i e s i n the postero-dorsal part of the body c a v i t y . When mature eggs are present, the ovary s w e l l s and MAX. LENGTH / TOTAL LENGTH 7T 15 mature females are n o t i c e a b l y bulged. The ovarian membranes are continuous w i t h the oviduct. The l a r g e r eggs are yellow-orange whereas small eggs tend to be l i g h t yellow. Eggs of three c l a s s e s determined by s i z e are described i n t h i s study. The average diameter was c a l c u l a t e d from measure-ments on eggs made wit h d i v i d e r s . The three c l a s s e s are as f o l l o w s : small - l e s s than one m i l l i m e t e r diameter; medium -one to two m i l l i m e t e r s ; and l a r g e - greater than two m i l l i m e t e r s i n diameter. The l a r g e eggs were probably mature and were des-t i n e d to be released i n the spawning of that season. An "imma-ture'11 c o n d i t i o n was a l s o observed. In the "immature" c o n d i t i o n ovarian s t r u c t u r e was recognizable m i c r o s c o p i c a l l y , but i n d i v i -dual eggs could not be discerned. The numbers of eggs of each s i z e c l a s s were counted. For the purposes of t h i s work, the term "complement" describes the number of eggs of given s i z e c l a s s present i n a f i s h . As pointed out by Vladykov (1956) the term " f e c u n d i t y " should be reserved fo r the number of mature eggs a c t u a l l y released at spawning. Annual Reproductive Condition Males The surface area of one t e s t i s lobe was determined f o r each male examined; the number of males i n each sample during the year ranged from 9 to 17• An average surface area value was deter-mined -for each sample ( F i g . k) * T e s t i s development was greatest during the period September to January. 1 6 40 < UJ g 30 V) U J u3 20 3 IQ •' - - - -15) (9) ( 1 ? / (21) \e) (12) A rHio) » XI5) / \ / ( l 7 ) N T X (!) 07) fl5) _ 12 3 4 5 6 7 DEC3/65 8 9 10 II 12 13 14 15 16 17 I I l MAY4/66 AUG 8/66 N0V13/S6 F i g . U, Annual v a r i a t i o n i n average s u r f a c e a r e a (mm^) o f one t e s t i s l o b e o f L. p a c i f i c a . The f i g u r e s i n b r a c k e t s i n d i c a t e t h e number o f males examined p e r sample. A l l f i s h were c o l l e c t e d a t o u t e r B u r r a r d I n l e t . AVERAGE COMPLEMENT m^edium eggs A large eggs 12 3 4 (13) fc!) I DEC.3/65 5 6 09(29 7 07) 8 (17) 9 (19) fcW4/66 10 11 12 13 14 15 16 02} (I8)(t$ (6} (3)03(20 I AUG8/S6 17 NOV 13/66 f i g . 5. Anr,u;.l v a r i a t i o n i n average complement o f t h r e e egg s i z e s i n L. p a c i f i c a . The f i g u r e s i n b r a c k e t s i n d i c a t e the number o f females examined p e r sample. A l l " f i s h were c o l l e c t e d a t o u t e r B u r r a r d I n l e t . 17 Females The complement of each s i z e c l a s s of eggs was determined during the year ( F i g . 5). The average i s c a l c u l a t e d from counts made on 13 to 21 i n d i v i d u a l s per sample. I t should be noted that the average complement of each s i z e c l a s s does not ade-quately represent the a c t u a l number of eggs present. Some i n -d i v i d u a l s would not contain any eggs of one p a r t i c u l a r s i z e . The average complement of medium eggs increased i n February, l e v e l l e d o f f u n t i l about l a t e August, then decreased ( F i g . 5 ) . In August mature eggs began to appear and s e x u a l l y mature f e -males were found u n t i l l a t e November of 1966. They were a l s o present i n samples taken i n December 1965. An undetermined p a t t e r n was observed f o r eggs of the small category. Small f i s h were r a r e l y obtained i n the c o l l e c t i o n s made by commercial shrimp v e s s e l s . Age and Length at Sexual M a t u r i t y As noted i n the s e c t i o n d e a l i n g with growth (p. 26) the^e i s overlap of le n g t h among the age groups of Lycodopsis p a c i f i c a . To determine the average age of sexual maturity i n L, p a c i f i c a would r e q u i r e many more age estimations than are a v a i l a b l e . Over the period of sexual maturity (approximately September to Janu-ary) the percentage frequency of s e x u a l l y mature i n d i v i d u a l s i n each ten m i l l i m e t e r l e n g t h group was determined. Females ranging i n l e n g t h between IZfO and 180 mm and males ranging i n len g t h from 170 to 230 mm were most fre q u e n t l y mature ( F i g s . 6 and 7)« 18 SIZE CLASS (mm.) Fig. 6. Histograms showing percent frequency of mature female L. pacifica by size class. Data from collections made in "December 1965, January 1966, and August-November 1966, at outer Burrard Inlet. co DO LL) U J § 80 >-o z L U o LL) 60 40 LLI o S20 0_ 0> o OJ at ro O ro t7> in • o CD ID O CT> r— O CT) oo o co o cn s I o o OJ 0> OJ I o OJ SIZE CLASS (mm.) Fig. 7. Histograms showing percent frequency of mature male L. pacifica by size class. Data from collections made in December 1965, -'urtuary 1966, and au^ ust-Hovembcr 1966, at outer Burrard Inlet. !9 From the above observations i t i s concluded sexual maturity i n Lycodopsis p a c i f i c a occurs approximately from September to January* Over t h i s p e r i o d , l a r g e s e x u a l l y mature males and fe-males appeared i n the samples. Inferences of Spawning Time Length frequency a n a l y s i s of specimens captured at the Cape Lazo area suggests breeding occurs i n l a t e f a l l and winter i n Lycodopsis p a c i f i c a . A sharp mode of small f i s h i s evident i n November I.965 and January 1966 ( F i g . 8), The mode has a peak of about 75-80 mm i n these months. By August-September 1966 the mode had s h i f t e d to approximately 100 mm, presumably because sampling had " f o l l o w e d " the growth of i n d i v i d u a l s produced by breeding i n f a l l and winter of 196^  and 1965. A mode of approximately 70 mm i s evident i n August and Sep-tember 1966 samples. This mode i s probably composed of young produced during the 1965-66 spawning season. Some i n d i v i d u a l s i n outer Burrard I n l e t apparently ceased feeding i n the f a l l and winter months because i n d i v i d u a l s w i t h empty stomachs were observed i n samples at these times ( F i g . 9)« These i n d i v i d u a l s could have been i n spawning c o n d i t i o n . Cessa-t i o n of feeding at spawning time i s common i n f i s h e s (Nikolsky, 1 9 6 3 ) . O v i p a r i t y , O y o v i v i p a r i t y and P a r e n t a l Care A wide range of reproductive types i s recorded among members of the Family Zoarcidae, BretSchneider and de Wit (19V7) show 20 CAPE LAZO GULLY August - September 1966 n=823 140 160 180 CAPE LAZO GULLY January 1966 n = 1372 100 120 160 180 CAPE LAZO GULLY November 1965 1354 i 1 1 1 1 r 60 180 200 LENGTH mm F i g . 8. Length frequency polygons o f L. p a c i f i c a captured a t the Cape Lazo g u l l y a t three sampling t i m e s . F i g . 9 . Percent frequency o f empty d i g e s t i v e t r a c t s observed i n L. p a c i f i c a d u r i j i g t he p e r i o d December 1 9 6 5 - November 1 9 6 6 . Data from samples o f 20 f i s h per time p e r i o d c o l l e c t e d at o u t e r B u r r a r d I n l e t . 22 that the v i v i p a r u s blenny, Zoarces v i v i p a r u s of northeastern A t l a n t i c waters, i s an "ovary breeder". The ova are f e r t i l i z e d i n the ovary and there develop i n t o young. Their work and that of Mcintosh (1885) show that the species i s ovoviviparous. Other north A t l a n t i c forms, f o r example Lycodes spp., are o v i -parous (Jensen, 1904). Macrozoarces americanus of the north-western A t l a n t i c was found to be oviparous by White (194-0) who discovered an egg mass guarded by the parents. Information on the reproduction of north P a c i f i c z o a r c i d s i s r a r e . Lycodes palearis spawned i n an aquarium but t h i s followed removal of the ma j o r i t y of the eggs by a r t i f i c i a l means ( S l i p p and De Lacy, 1952). B a l i and Bond (1959) record ovum s i z e from specimens of Aprodon cortezianus from the Oregon coast. They concluded the species i s oviparous and spawns i n l a t e summer or e a r l y f a l l . Andriashev (1937) notes the ova s i z e of Lycodes spp, from the Bering and Chukchi Seas. Clemens and Wilby (1961) w r i t e "some of the species (of Family Zoarcidae), p o s s i b l y a l l , give b i r t h to young." No evidence of o v o v i v i p a r i t y or v i v i p a r i t y was found f o r L, p a c i f i c a i n the present study. I t i s p o s s i b l e that f e r t i l i z a -t i o n i s i n t e r n a l and that development occurs f o r a short period i n s i d e the maternal body. There i s no evidence that t h i s i s the case, however, e i t h e r from d i r e c t observation or from the pres-ence of any anatomical m o d i f i c a t i o n s f o r i n t e r n a l f e r t i l i z a t i o n and i n c u b a t i o n . Most i c h t h y o l o g i s t s accept the g e n e r a l i z a t i o n that the con-d i t i o n s of low fecundity and l a r g e eggs are u s u a l l y accompanied F i g . 10. Male and fe.nale Lycodopsis p a c i f i c a on the ocean f l o o r . Photograph taken by Dr. E.W. Fager i n November 1965 o f f La J o l l a , C a l i f o r n i a , at a depth of 110 m. 2k by some degree of p a r e n t a l care. The present study shows L, p a c i f i c a has a very small complement of mature eggs. The mature eggs are l a r g e , w i t h an average diameter of 5 mm. Between Sep-tember 1 9 6 5 and January 1 9 6 6 the average complement of l a r g e eggs was 3 0 , ^ (range 7 to 5 2 ) i n 5 1 i n d i v i d u a l s examined. This average complement i s an approximation to fecundity. I n d i r e c t evidence of p a r e n t a l care i n L. p a c i f i c a i s provided by Fager's (pers. comm. 1 9 6 6 ) observations from submersibles o f f the southern C a l i f o r n i a coast i n 19&k and 1 9 6 5 . During dives i n f a l l and winter he observed L. p a c i f i c a commonly i n male and female p a i r s ( F i g . 1 0 ) . On one occasion he observed a p a i r c l e a r i n g a patch of sediment together. I t appeared as i f a "burrow" were being constructed. Age and Growth Ages of specimens of Lycodopsis p a c i f i c a from outer Burrard I n l e t were estimated using the l e f t sacculus o t o l i t h . The annular r i n g s were counted under d i r e c t l i g h t w i t h a microscope of XlO m a g n i f i c a t i o n . Subsampling techniques f o r s e l e c t i o n of o t o l i t h s and c r i t e r i a f o r annular r i n g s are o u t l i n e d i n the Appendix, p. 7k* The annular r i n g s are assumed to be formed by temperature-dependent phenomena. The ages of 1 2 9 males and 1 0 7 females were estimated. Ages ranged up to f i v e years f o r both sexes ( F i g , 1 1 and Appendix, pp.76 and 7 7 ) . Regression l i n e s d e s c r i b i n g growth f o r both sexes were obtained by l e a s t squares estimation a f t e r transforming values to logarithms. The r e g r e s s i o n equations obtained are as AGE - YEARS Fie. 11. Age-length relationship of L. p a c i f i c a . Ordinate - mean length i n millimeters; Abscissa - age i n years. Dsta from specimens collected at outer Burrard Inlet. 26 f o l l o w s : Males: Y = -+,4982 + 0.5191X Females: Y = if, 5382 + 0.-+502X A t - t e s t f o r d i f f e r e n c e s between the slopes of the two equations was performed ( S t e e l and T o r r i e , I960), A t-value of 6 . 8 9 0 was s i g n i f i c a n t at the 95% p r o b a b i l i t y l e v e l . I t i s con-cluded that males grow f a s t e r than females a f t e r approximately 170 mm i n l e n g t h . The d i f f e r e n c e i n growth r a t e i s probably of importance i n sexual dimorphism, and i s discussed on p. 1 3 , L i m i t e d v e r i f i c a t i o n of the ages estimated from o t o l i t h s was obtained by a n a l y s i s of leng t h frequency data. In l a r g e samples from the Cape Lazo g u l l y , the modes of ages I , I I , and perhaps I I I are prominent i n leng t h frequency polygons ( F i g . 8 ) . At greater ages there i s much overlapping of leng t h groups, Length-Weight R e l a t i o n s h i p Specimens captured at the Cape Lazo g u l l y on March 18 1967 were used i n t h i s i n v e s t i g a t i o n . A f t e r removal from the t r a w l the f i s h were wrapped i n d i v i d u a l l y i n cheesecloth to remove excess water. Weights and lengths were obtained not more than 12 hours a f t e r capture. Weights were made to the nearest d e c i -gram and lengths to the nearest m i l l i m e t e r . Weights and measurements of 62 males and if6 females were obtained ( F i g , 1 2 ) . A l i n e of best f i t was c a l c u l a t e d f o l l o w i n g the l e a s t squares method o u t l i n e d i n Carlander ( 1 9 5 0 ) . The equation expressing the r e l a t i o n s h i p i s W - 0,OOOOifl9L^*0'^^''7 where W (weight) i s i n grams and L (length) i s i n m i l l i m e t e r s . 27 30 25 E 20 x CD 6 MALE n = 62 A F E M A L E n = 4 6 e © 15 10 0 A o 50 100 150 LENGTH (mm.) 200 Fig. 12. Length-weight relationship of _L. pacifica. Data from fre specimens collected at the Cape Lazo gully on March 18 1967. 28 Food of Lycodopsis -pacifica From each of the 17 samples obtained during the year, the stomach and i n t e s t i n a l contents of 20 i n d i v i d u a l s were examined. A l l i d e n t i f i a b l e items were enumerated. Recognizable organisms were counted as one item. Annelid worms were o f t e n broken so a s e c t i o n one centimeter long was counted as an item, Lycodopsis p a c i f i c a feeds p r i m a r i l y on the infauna of a soft-bottom community. D e t r i t u s and sediments were found i n a l l i n d i v i d u a l s i n tr a c e amounts. A l i s t of recorded food organisms f o l l o w s . Phylum Annelide C l a s s Polychaeta Subclass E r r a n t i a F. S y l l i d a e F. Nereidae Subclass Sedentaria F. Chaetopteridae - Phyllochaetopterus spp. F, Sternapsididae - Sternapsis spp. Phylum Arthoropoda Subphylum Crustacea C l a s s Ostracoda Order Myopoda Class Copepoda C l a s s Malacostraca Subclass P e r i c a r i d a Order Cumacea Order Amphipoda 2 9 Suborder Gammaridea - Amphithoe spp. Suborder Hyperiidea - Hyperia spp. Order Decapoda Suborder Natantia Section Caridea - Pandalus spp. Suborder Reptantia Section Macrura - Cancer magister (megalopa) - P i n n i x a spp. Phylum Mollusca C l a s s Gastropoda F, Amphictenidae - Pec t e n a r i a spp. Class Pelecyopoda Order Protobranchia - Y o l d i a e n s i f e r a - Y o l d i a amygdalea Order Eulammellibranchia - Macoma c a r l o t t e n s i s ~ Axinopsis s e r i c a t u s The food items were categorized i n t o ten major groups. These were: b i v a l v e s (Pelecypoda), amphipoda, f r e e - l i v i n g an-n e l i d s (Polychaeta, F, Nereidae), "peanut worms" (Polychaeta, F. Sternapsididae), tubeworms (Polychaeta, F, Chaetopteridae), gastropods, cumaceans, ostracods, megalopa l a r v a e (Cancer magister), decapod crabs, copepods, and pandalid shrimps. The percentage abundance by number of each item i n each sample ( F i g , 13), and the percentage abundance by number of each item averaged over a l l the samples ( F i g , Ik) were determined. B i v a l v e s , tube worms, amphipods, and f r e e - l i v i n g a n nelids dom-i n a t e the food spectrum. 30 DEC3/65 50-50-50-O JAN 9 /66 MAR 6/66 _ <5 CL 0 o £ Kt „ MAR 21/66 o °- o a . p l APR 10/66 50-1 .0 MAY 4/66 a o ° _ u _ „_ _ c/> °~ Fig. 13. Percent abundance by number of Data from 20 fish per time period collec A-Amphipoda; B-3ivalve rolluscs; CO-Cope Decaporia Reptantia(adults); DM-Decapoda Reptantia(megalopa); G— Gastropod mollusc (Pectenaria spp.); O-Cstracoda; PE-Polyc Polychaeta Sedentaria( Phyl.lochaet.optcrus Sedent;- ria( Sternapsis spp.). food items of L. pacifica. ted at outer Burrard Inlet, ooda; Cu-Cumacea; DliA-Natantia; DRJl-Decapoda s; GP- Gastropod molluscs .aeta Errantia; PSP-spp.); PSS-Polychaeta 31 6 0 CO >-CO UJ O a ZD CQ < r -LU O CC LJ Q_ 50 4 0 30 0_ 00 CO-LLI CD < rc LU > < 20 10 < 6 7 8 9 10 F i g . 14. Average percent abundance by number of food items found in 340 digestive tracts of L. pacifica. A l l fish collected at outer Burrard Inlet December 1965-November 1966.' A-Amphipoda; B~Bivalve molluscs; CO-Copepoda; CU-Cumacea; DRA-Decapccia Heptantia(adults); DN-Decapoda Natantia; DHM-Decapoda Reptantia(megalopa); G-Gastropod molluscs; GP-G;jstropod molIuscs(Pectenaria spp.); 0-Ostracoda; PE-Polychaeta Errantia; PSP-Polychaeta Sedentaria(Phyllochaetopterus spp.); PSS-Polychaeta Sedentaria (Sternapsis spp.). 32 Seasonal D i f f e r e n c e s i n Food Stomach content data from specimens c o l l e c t e d at the West Vancouver f i s h i n g area were used to t e s t the hypothesis that the food of Lycodopsis p a c i f i c a v a r i e d seasonally. C o l l e c t i o n s of December 3 1965 and January 9 1966 were considered winter samples. C o l l e c t i o n s of J u l y k and 21 1966 were considered summer samples ( F i g . 15)• A nonparametric t e s t was employed to determine i f the food spectrum d i f f e r e d seasonally. Kendall's rank c o r r e l a t i o n c o e f f i c i e n t , tau, was c a l c u l a t e d as o u t l i n e d i n S i e g e l (1956). In these t e s t s both percentage abundance by number and percent frequency of occurrence of food items were considered. For percent abundance at tau value of 0.733 i s not s i g n i f i c a n t at the 95% l e v e l ( p r o b a b i l i t y of r e j e c t i n g i s 0.1762). A tau value of 0.712 was computed f o r per cent f r e -quency. This value i s a l s o not s i g n i f i c a n t at the 95% l e v e l ( p r o b a b i l i t y of r e j e c t i n g i s 0,1814). The t e s t s i n d i c a t e that the food of L. p a c i f i c a can vary seasonally. Such d i f f e r e n c e s as do occur may a r i s e from seasonal v a r i a t i o n s i n abundance and a v a i l a b i l i t y of such food items as amphipods, copepods, cuma-ceans, and ostracods. Place of C o l l e c t i o n and Food I t was hypothesized that d i f f e r e n t i n f a u n a l communities might be present at West Vancouver and Spanish Banks, The gut contents of Lycodopsis p a c i f i c a might i n d i c a t e such a d i f f e r e n c e . The d i g e s t i v e t r a c t contents of 60 f i s h c o l l e c t e d at Spanish Banks were a v a i l a b l e , and 220 were a v a i l a b l e from West Vancouver. 33 Ul o z LU DC O O o O >-o z LU ZD O LU cc 80F 60 40 20 Z> WINTER DEC. 3 /65 JAN.9 /66 0 -J C3 H' J L "" 100 LU O z iii rr ZD O o o 80 60 >-o z LU Z> O LU OC LL. 40 20 SUMMER JULY 4,21/66 0 100 or LU CD CQ LU O z < Q Z z> < 80 60 40 20-0 SUMMER JULY 4,21/66 83 o [ 1 § WEST VANCOUVER FiE. 15. Histograms displaying seasonal differences in the food spectrum of L. pacifica. All specimens collected at the '.-.'est Vancouver fishing area in outer Burrard Inlet._ A-A.nphlpoda; 3-Bivalve molluscs; CO-Copepoda; CU-Cumucea; DRA-Uecapoda .Heptantia(adults); M-Decapoda Matantia; DRM- Decapo;:a Reptnntia(rae(-alo-a); G-Castropod nolluscs; GP-Castropod molluscs (Pectena ria spp.); 0-0straccda; PE-Polychaeta iirrantia; PS?-?olychaeta Sedentaria (Phyllochaetopterus spp.); PSo-Polychaeta Sedentaria (Sternapsis spp.). 34 K e n d a l l ' s rank c o r r e l a t i o n c o e f f i c i e n t , tau, was c a l c u l a t e d as o u t l i n e d i n S i e g e l (1956). Both percentage abundance by number and percent frequency of occurrence were considered ( F i g , 16). Tau values of 0,192 and 0,117, r e s p e c t i v e l y , were not s i g n i f i c a n t at the 95% p r o b a b i l i t y l e v e l . The t e s t s i n d i c a t e that the gut contents were d i f f e r e n t at Spanish Banks compared to West Van-couver. The major items which v a r i e d i n importance were errant polychaetes (F. Nereidae) and sedentary polychaetes of the F a m i l i e s Chaetopteridae and Sternapsididae. This may i n d i c a t e a d i f f e r e n c e i n the s o f t bottom community and perhaps a d i f -ference i n sediments at the two s i t e s . Changes i n the Food Spectrum w i t h Growth The food spectrum of a species may change as i n d i v i d u a l s grow. Specimens c o l l e c t e d i n a s i n g l e t r a w l at the Cape Lazo study area were used to i n v e s t i g a t e t h i s matter. The c o l l e c t i o n was made on January 23 1966. The stomach contents of f i v e i n d i -v i d u a l s of each f i v e m i l l i m e t e r length group were examined and the per cent abundance by number of each item was determined. Figure 1 ? i n d i c a t e s a greater v a r i e t y of food items are found i n L. j ^ ^ i f i c a of lengths approximately 100 mm and over. Lycodopsis p a c i f i c a as a Member of the Bottom Community In outer Burrard I n l e t , Lycodopsis p a c i f i c a feeds upon a b i v a l v e - a n n e l i d community. Many of the i n v e r t e b r a t e s recorded i n the food spectrum of the species are components of the com-munities that Shelford (1935) suggests f o r Puget Sound approxi-35 100 WEST VANCOUVER 100 SPANISH BANKS Fig. 16. Histograms displaying spatial differences in the food spectrum of L. pacifica. Spanish Banks data from 60 digestive tracts; '.Vest Vancouver1 data from 220 digestive tracts. Fish collected during December 1965 to November 1966. A-Auphipoda; B-Bivalve molluscs; CO-Copepoda;-CU-Cumacea; DRA-Decapo-ia Heptantia(adults); DS-Decapoda Katar.tia; DRM--Decapoda Keptantia(raegalopa); G-Gastropod molluscs; GF-Gastropod molluscs (Pectenaria spp. ); 0-Ostiacoda; PE-Polychaeta Krrantia; PSP-Polychaeta Sedentaria(FhylIochaetopU'rus spp.); PSS-Polycnaeta Sedentaria CSternapsis spp. 100 X o MA 80 o 5 -CO LU 60 > LL. 21 LU O 40 z: < Q AB 20 H LU LU CL 6 1*3 UJ < 1 1 CO ON 5-74 75-84 95-104 105-114 115-124 125-134 135-144 145-154 155-164 165-174 LENGTH GROUP (mm) Fig. 17. Histograms of percent abundance by number of various food items of L. pacifica over the indicated length range. Samples taken at the Cape Lazo study area in January 1966. A-Amphipoda; B-Bivalve molluscs; CO-Copepoda; CU-Cumacea; DKA-Decapoda Reptantia (adults); DN-Decapoda Matantia; DKM-Decapoda Heptantia(megalopa); G-Gastropod molluscs; GP-Gastropod molluscs(Pectenaria spp.); O-Ostracodaj' PE-Polychaeta Errantia; PSP-Polychaeta Sedentaria(Phyllochaetopterus spp.), PS5-Polychaeta Sedentaria (Sternapsis spp.J. 37 raately 100 miles south of Burrard I n l e t , Shelford (1935) terms L. p a c i f i c a an i n f l u e n t species of an " a s s o c i a t i o n " , a "biome", and an "ecotone community". He does not define the term " i n -f l u e n t species" but probably means an organism which occurs of t e n i n a s s o c i a t i o n w i t h a d i s c r e t e assemblage of animals. Mobile e p i f a u n a l animals such as L* p a c i f i c a are d i f f i c u l t to categorize i n t o d i s c r e t e assemblages. Ting (MS 1965) developed a new type of sampler f o r demersal animals and he t e s t e d the device i n Puget Sound f o r use i n com-munity a n a l y s i s on muddy bottoms. He determined a close a s s o c i -a t i o n among Lycodopsis p a c i f i c a , Lyopsetta e x i l i s , P o r i c h t h y s nojtatus, Compsomya subdiaphana, Macoma i n f l a t u l a , Nucula cas-t r e n s i s and Phacoides c e n t i l o s a i n the mud community. These data i n d i c a t e that L. p a c i f i c a i s a component of a mud community. A l l animals c o l l e c t e d i n the experimental t r a w l i n g at outer Burrard I n l e t were enumerated. The census included 75 ten-minute t r a w l s made i n May and June 1966. P e r t i n e n t dimensions of the t r a w l are found i n Table I I I , p. & Fishes c o l l e c t e d were mainly demersal or. bottom, forms although some p e l a g i c species were recorded. The i n v e r t e b r a t e s captured were a mixture of i n -faunal and e p i f a u n a l species ( d e f i n i t i o n according to Petersen, 1913 i n Thorson, 1957)« Lycodopsis p a c i f i c a occurred i n t r a w l s w i t h members of 15 f a m i l i e s of f i s h e s ( c l a s s i f i c a t i o n of Berg, 1941)» Pleuro-n e c t i d s were represented by T l species, Gadidae and Cottidae were represented by three species each. One or two species of the remaining f a m i l i e s were captured, A faunal l i s t of the f i s h 38 species c o l l e c t e d i s found i n the Appendix, page 7 ©•. Lycodopsis p a c i f i c a dominated the catches. The species occurred i n 90,6% of the t r a w l s . The p l e u r o n e c t i d species Glyptocephalus z a c h i r u s , Microstomus p a c i f i c u s and Lyopsetta e j c i l i s ^ ranked a f t e r L. p a c i f i c a i n per cent frequency of occur-rence. Glyptocephalus zachirus occurred i n 77\h% of the t r a w l s , Microstomus p a c i f i c u s i n 77«0%, and Lyopsetta e x i l i s i n 55*h%* There i s no evidence that any of the species captured i n the t r a w l s prey on L, p a c i f i c a . The p i s c i v o r o u s species r e -corded, f o r example Atheresthes stomias,. were immature and were incapable of i n g e s t i n g L, p a c i f i c a of the s i z e range encountered, The i n v e r t e b r a t e s captured i n the t r a w l s were members of the Phyla Echinodermata, Coelenterata, Mollusca, Platyhelrnin-thes and Subphylum Crustacea ( c l a s s i f i c a t i o n f o l l o w i n g Barnes, 1963 and B o r r a i d i l e and P o t t s , 1963). Members of the Order Decapoda (Subphylum Crustacea), i n p a r t i c u l a r Tribe Natantia, were most abundant and occurred most fr e q u e n t l y , Cragnon com-munis, f o r example, occurred i n 93.2% of the t r a w l s , Spironto-c a r i s holmesi and Pandalus spp, were a l s o frequently captured. A member of the T r i b e Reptantia of t h i s order, Caneer magister, occurred i n 87.9% of the t r a w l s . For faunal l i s t of the i n v e r -tebrates captured see the Appendix, pp. 80 and 8.1. MORPHOLOGY y FEEDING AND SEDIMENTS The o b j e c t i v e of the f o l l o w i n g s e c t i o n i s to describe and i n t e r r e l a t e the anatomy of the feeding s t r u c t u r e s and feeding h a b i t s of Lycodopsis p a c i f i c a . The o r i g i n a l working hypothesis f o r t h i s i n v e s t i g a t i o n was based on statements from Jones (1950) "There i s no complete s p e c i a l i z a t i o n (of feeding) on any one type of d e p o s i t / ai£& tlie evidence does not i n d i c a t e that feeding h a b i t , i n the broad sense, i s of paramount importance i n r e s t r i c t i n g species to a p a r t i c u l a r type of bottom. Neverthe-l e s s , i t i s p o s s i b l e that c l o s e r examination of i n d i v i d u a l a n i -mals w i l l show i t to be-imp|brtant i n many cases". In the above statements, Jones i s r e f e r r i n g to the morpho-l o g i c a l , , p h y s i o l o g i c a l and behavioural adaptations of i n f a u n a l i n v e r t e b r a t e s . I t was hypothesized that the concept of " s p e c i -a l i z a t i o n of feeding habit:on one p a r t i c u l a r d eposit" might be a p p l i c a b l e to Lycodopals p a c i f i c a . Studies of the food show L. p a c i f i c a i s capable of feeding on se v e r a l components of a s o f t -bottom community. The species i s probably an "opportunist" and i s able to i n g e s t a v a r i e t y of i n f a u n a l (and epifaunal) organ-isms, w i t h i n the c a p a b i l i t i e s of s t r u c t u r e s associated with food g e t t i n g . The feeding adaptations of marine bottom f i s h e s have not been studied. Nikolsky (1963) p o i n t s out that the feeding habit of f i s h e s are determined p r i m a r i l y by the abundance of food organisms present i n the environment to which the f i s h e s are adapted. Thorson (1907) has pointed out the s t a b i l i t y i n abundance of most infauna!.organisms of the soft-bottom communi-t i e s . Keast and Webb (1966) show how d i f f e r e n c e s i n mouth and body form i n r e l a t i o n to feeding ecology may separate co-h a b i t i n g species of freshwater f i s h , Moiseev (1952), i n a paper d e a l i n g with f i s h e s of the north-west P a c i f i c , s t a t e s "... a f a i r l y well-guaranteed food supply, the v a r i e t y and r e l a t i v e s t a b i l i t y of the biocoenotic grouping has l e d to a c l e a r d i f f e r e n t i a t i o n of the most numerous species (small-mouthed flounders, large-mouthed flounders, cod and Alaska p o l l a c k ) . " Here i s mention of feeding morphology i n r e -l a t i o n to food supply. The comment may have i t s p a r a l l e l i n some f j o r d s of the B r i t i s h Columbia coast. In at l e a s t some i n l e t s , L. p a c i f i c a i s a dominant member of the bottom f i s h fauna. A, Mouth Form The mouth of L, p a c i f i c a may be described as "shovel shaped." Large mature males.have been termed " a l l i g a t o r heads." The snout terminates i n a blunt p o i n t and the mouth i s n e a r l y h o r i z o n t a l with the body a x i s . The lower jaw i s included i n the gape. The l i p s are w e l l - d e f i n e d and f a i r l y l a r g e , In t h i s d e s c r i p t i o n of the species, B a y l i f f (MS, 1954) gives p e r t i n e n t measurements. In the present study the mouth form of L. p a c i -tlca i n s e v e r a l aspects i s shown i n F i g s . 18 and 19. B, Buccal, Pharyngeal and Esophageal Regions The buccal apparatus of L. p a c i f i c a i s well-equipped with s t r u c t u r e s f o r h o l d i n g food i n the o r a l c a v i t y , The 15 pre-m a x i l l a r y teeth are arranged i n a s i n g l e s e r i e s . The d e n t a r i e s are each covered w i t h 20 teeth which form a patch a n t e r i o r l y and which are reduced p o s t e r i o r l y to a s i n g l e s e r i e s . A l l teeth are approximately equal i n s i z e ( B a y l i f f , MS, 1954)* Further Fig. 18. Anterior views of the buccal region of L. pacifica ( H i ) 42 PHARYNGEAL PADS SIDE VIEW - CUT THROUGH LEFT ANGLE OF JAW PHARYNGEAL PADS FRONT VIEW SLIGHTLY FROM THE LEFT Fig. 19. Lateral and anterior views of the buccal region of L. pacifica (Xl|) 43 p o s t e r i o r ojn the f l o o r and roof of the buccal c a v i t y two e l l i p i -t i c a l developments of " f l e s h f o l d s " or rugae occur. P o s t e r i o r to these are a s e r i e s of f o l d s which extend to the region of the pharyngeal pads ( F i g , 1 8 ) . The pharyngeal pads are l a r g e f l e s h y mats (length r a t i o 0»46 of p r e m a x i l l a r y l e n g t h i n ten mature male specimens) l o -cated i n the p o s t e r i o r part of the buccal c a v i t y . They are separated m e d i a l l y by c o n t i n u a t i o n s of the rugae, and each pad i s d i v i d e d i n t o three p a r t s by muscular septa continuous with the b r a n c h i a l apparatus. The pads are set l o o s e l y i n depres-s i o n s , and are covered with s e v e r a l hundred horny " t e e t h " which are opposed by the f l a t t e n e d g i l l r a k e r s . The isthmus of the b r a n c h i a l apparatus i s triangular-shaped, covered with " t e e t h " , and p a r t l y opposes the pharyngeal pads, The pharynx opens at the p o s t e r i o r end of these pads, C, Stomach and I n t e s t i n e The elongated i n t e s t i n e ranged i n l e n g t h from Cv36 to 0 . 5 9 of the t o t a l length of the f i s h (mean of O .48 based on 20 i n d i -v i d u a l s ) , B i v a l v e molluscs are digested i n the i n t e s t i n e when not crushed by the pharyngeal pads. A v a r i a b l e number of small caeca (6 to 7 i n ten specimens) are l o c a t e d near the duodenum. Location of other d i g e s t i v e organs i s approximately as described by MacKay (1926) f o r Macroaoarces americanus. The feeding morphology of Lycodopsis p a c i f i c a enables the species to obtain the most abundant food i n i t s h a b i t a t , L, p a c i f i c a i s r e s t r i c t e d to close a s s o c i a t i o n with the bottom. No swim bladder i s present, and the species probably r a r e l y swims o f f the bottom. I t i s speculated L, p a c i f i c a removes i n f a u n a l organisms from the sediments by a " s i f t i n g " process. The pharyngeal pads and associated s t r u c t u r e s are adaptations which a i d i n crushing and g r i n d i n g of i n f a u n a l i n v e r t e b r a t e s . The elongated i n t e s t i n e may be an adaptation to d i g e s t i o n of pele-cypods. Sense Organs and Food Detection Anatomical observations of the b r a i n of Lycodopsis p a c i -f i c a were made. The o l f a c t o r y nerve ( I ) i s reduced, and the o l f a c t o r y lobes of the b r a i n are poorly developed. The nerve leads a n t e r i o r l y and innervates a r o s e t t e l o c a t e d under the nasal flap,. The f a c i a l nerve (VII) was found to be very w e l l developed, and equalled the o p t i c ( I I ) i n diameter, A branch of the f a c i a l nerve innervates the masseter muscle, and a major component continues a n t e r i o r l y to the r o s e t t e mentioned above. Other branches innervate the f l e s h y f o l d s of the m a x i l l a r y and pr e m a x i l l a r y regions ( F i g , 20), The f a c i a l nerve i s composed of mixed sensory and motor f i b e r s ( E r i c k s o n , 1963). E r i c k s o n (1963) emphasizes that "oro-pharynageal sensa-t i o n s " are e s s e n t i a l when an animal must f i n d food and eat i t . For f i s h e s l i v i n g on a s o f t bottom, gus t a t i o n would be of ad-vantage i n l o c a t i n g i n f a u n a l food items. Gustatory sense f i b e r s i n the f a c i a l and other nerves may be of considerable importance i n the feeding behaviour of L, p a c i f i c a . Animals maintained i n the aquarium were observed to r e s t on t h e i r expanded p e c t o r a l f i n s . The reduced p e l v i c f i n s contact CEREBELLUM MEDULLA OBLONGATA OPTIC LOBES •E-PREM AXILLARY MAXILLARY Fig. 20. , D o r s a l v i e w o f t h e b r a i n a n d c r a n i a l n e r v e s o f L . p a c i f i c a (X3) the substrate, F r i e h o f e r (1963) describes the patter n of i n -nervation v i a the f a c i a l nerve (VII) i n t h i s region f o r Lyco-dopsis p a c i f i c a . I t was hypothesized that cutaneous sense organs might be found i n the reduced p e l v i c s of L. p a c i f i c a . The p e l v i c f i n s of f i v e specimens were stained with haemotoxylin and eosin, sectioned, and examined under the micro-scope. "Sense organs" were not observed. However, i n the epidermis of the v e n t r a l body surface were found c e l l s l o c a t e d i n p i t s . The s t r u c t u r e s resembled "sense organs" or "sense c e l l s " described by other workers i n d i f f e r e n t species of f i s h , Jakubowski (i960) reported s i m i l a r s t r u c t u r e s i n the v i v i p a r u s blenny (Zoarces v i v i p a r u s ) and the e e l ( A n g u i l l a a n g u i l l a ) . Epidermal sense organs were recorded by Moore (1950) for minnows l i v i n g i n the muddy f r e s h waters of c e n t r a l North America. Observations of feeding behaviour i n the aquarium are of i n t e r e s t i n t h i s d i s c u s s i o n , The i n d i v i d u a l s maintained on f i n e sediments i n March 1966 were observed to cough frequently, "Coughing" released i n f a u n a l i n v e r t e b r a t e s from the mud. The food items might be ingested during the i n h a l e n t r e s p i r a t o r y movement. I n d i v i d u a l s maintained i n the aquarium on "coarse" s e d i -ments i n December 1966 d i d not show the "coughing" behaviour mentioned above. They were not observed to feed on the i n -faunal Phyllochaetopterus spp, that were abundant i n the sub-s t r a t e , The f i s h fed r e a d i l y on chopped raw oysters and f i s h . They appeared to be able to detect food items dropping from the kl surface before the items reached the bottom. Samples from outer Burrard I n l e t i n d i c a t e that Lycodopsis p a c i f i c a occa-s i o n a l l y ingested p e l a g i c organisms that ventured close to the bottom. Examples of such organisms found i n the d i g e s t i v e t r a c t s are megalopa l a r v a e of Cancer magister and Hyperid am-phipods (Hyperia spp.). These organisms might be detected v i s u -a l l y by L, p a c i f i c a . The eyes of the species are d i r e c t e d d o r s a l l y ( F i g . 10), enabling d e t e c t i o n of m a t e r i a l f l o a t i n g near the bottom. However, the vast m a j o r i t y of the food items recorded from the d i g e s t i v e t r a c t s of the species are r e l a t i v e l y s e s s i l e i n -faunal i n v e r t e b r a t e s ( f o r example, sedentary polychaetes, cuma-ceans, gastropods, and pelecypods) ( F i g . Ik)• Some of these organisms are probably found below the mud surface, and might not be detected v i s u a l l y . The food spectrum of the species i n d i c a t e s Lycodopsis  p a c i f i c a i s an "opportunist". Anatomical evidence suggests the species i s adapted to eat benthic i n f a u n a l i n v e r t e b r a t e s , but i s not s p e c i a l i z e d to one p a r t i c u l a r type of food organism. I f bottom type r e s t r i c t s the components of the bottom community i n outer Burrard I n l e t , the evidence i n d i c a t e s L. p a c i f i c a i s not s p e c i a l i z e d to one p a r t i c u l a r type of deposit. Within the scope of i t s morphology a v a r i e t y of organisms are removed from s e d i -ments and eaten by the species. For a given area, there are probably c e r t a i n l o c a t i o n s where maximum concentrations of s u i t a b l e i n f a u n a l food organisms are found. These l o c a t i o n s may by c o r r e l a t e d with sediment type. SEDIMENTS AND ABUNDANCE OF Lycodopsis p a c i f i c a E l t o n (19^9) pointed out that no h a b i t a t i s homogeneous and that clumping of animal populations i s common, The pa t t e r n of "clumping" i s probably determined by two sets of f a c t o r s , the behaviour of the species and the p h y s i c a l heterogeneity of the h a b i t a t . I t i s p a r t i c u l a r l y d i f f i c u l t to study these two f a c -t o r s simultaneously i n the s u b - l i t t o r a l marine environment, Verwey (19^9) mentions that "non-burrowing, bottom-dwell-i n g , mobile" forms do not show d i s t i n c t h a b i t a t s e l e c t i o n f o r a p a r t i c u l a r substratum. For a p a r t i c u l a r area, however, the feeding aggregations of the species may be l a r g e s t where s u i t -able food organisms are concentrated and where feeding mor-phology can operate most e f f i c i e n t l y . The concentrations of infauna may be r e l a t e d to the p h y s i c a l nature of the substrate, A f i e l d experiment was performed i n outer Burrard I n l e t to t r y and determine i f Lycodopsis p a c i f i c a aggregated on c e r t a i n sediment types, A d d i t i o n a l i n f o r m a t i o n was c o l l e c t e d at the Cape Lazo area. D e s c r i p t i o n of Sediments Sediments are described by marine g e o l o g i s t s according to systems based on median or modal diameter of the p a r t i c l e s com-posing the sediment (Shepard, 1963)« Generally, p a r t i c l e s of diameters greater than 62 microns are c a l l e d sand. S i l t s and c l a y s are p a r t i c l e s of diameters l e s s than 62 microns diameter, Folk (1965) o u t l i n e s techniques f o r determining median or modal g r a i n s i z e . The method i n v o l v e s screening and f r a c t i o n a l 49 weighing of sands. S i l t s and c l a y s are analyzed by p i p e t t e or hydrometer, u t i l i z i n g d i f f e r e n t i a l s e t t l i n g r a t e s i n water, Beanland (1940), Holme (1949), Chapman (1949), Okuda and Sato (1955), and Webb (1958) have stressed the importance of the i n t e r s t i t i a l spaces between sediment p a r t i c l e s . These workers f e e l some measure of the i n t e r s t i t i a l space may be a c r i t i c a l f a c t o r f o r bottom-dwelling animals. The i n t e r s t i t i a l space may be measured by a v a r i e t y of methods i n c l u d i n g median or modal g r a i n s i z e , p e r m e a b i l i t y or p o r o s i t y as measured by water content, per cent f i n e and per cent coarse sediments ( s i l t and sands), and various packing models. At the outer Burrard I n l e t experimental area, the per cent s i l t and per cent sand i n each sediment sample was used as a d e s c r i p t i o n of the substrate. The value was computed from the dry weight r a t i o of p a r t i c l e s l e s s than 62 microns i n diameter to p a r t i c l e s greater than 62 microns i n diameter. Bottom samples from the Cape Lazo g u l l y were analysed f o r modal g r a i n s i z e i n August 1966 by Dr. R, Sheldon, The data were k i n d l y made a v a i l a b l e to the w r i t e r . The techniques em-ployed f o r a n a l y s i s i n v o l v e d use of the Coulter counter. Tech-n i c a l d e t a i l s are found i n Sheldon and Parsons (1967). Sampling P a t t e r n s At outer Burrard I n l e t , three sampling t r a n s e c t s were designated ( F i g , 1); t r a w l and grab s t a t i o n s were at 5 fm (9.2 m) i n t e r v a l s . The depth range was 5 fm (9.2 m) to 25 fm (45»4 m). Each s t a t i o n was sampled with the experimental t r a w l 50 f i v e times i n May and June 1966, The f o l l o w i n g a b b r e v i a t i o n s are used when r e f e r r i n g to the t r a n s e c t s : SB represents Spanish Bank tr a n s e c t , P represents Point Grey tran s e c t , and N repre-sents North Arm t r a n s e c t . The number f o l l o w i n g the abbrevia-t i o n i n d i c a t e s the depth of sampling i n fathoms. The Cape Lazo g u l l y was sampled along nine s e c t i o n s ( F i g , 2 ) . The sampling depths across the s e c t i o n s were at approxi-mately 5 fm (9.2 m) i n t e r v a l s . Each depth was sampled a v a r i a b l e number of times. To obtain sediments, a Dietz-Lafond bottom sampler (see Shepard, 1963) was used at both study s i t e s . R e s u l t s and A n a l y s i s Catches of Lycodopsis p a c i f i c a at outer Burrard I n l e t ranged from 0 to lk3 i n d i v i d u a l s per t r a w l (Table I V ) , At the Cape Lazo g u l l y , the catches ranged from 0 to k7k i n d i v i d u a l s per t r a w l . Sediment at outer Burrard I n l e t ranged from 2,if% s i l t to 99.7% s i l t (Table I V ) , Modal g r a i n s i z e i n the Cape Lazo g u l l y ranged from 58 to 250 microns. Approximate contours of modal g r a i n s i z e i n the g u l l y are shown i n F i g , 23. The sampling p a t t e r n at outer Burrard I n l e t was designed to t e s t s t a t i o n d i f f e r e n c e s i n abundance by a n a l y s i s of v a r i -ances Normalization of data was achieved by a l o g (X + 1) transformation ( S t e e l and T o r r i e , i 9 6 0 ) , The procedure was necessary because of zero catch values i n s e v e r a l hauls. A l l analyses of variance a p p l i e d to the catch data were 51 Table IV, Catches of L, p a c i f i c a per ten minute trawl at the outer Burrard I n l e t experimental area* Dates of sampling May and June 1966. The sediments at each s t a t i o n are al s o described. DEPTH 5 fm 10 fm 15 fm 20 fm 25 fra 09,2 m) (18.3 m) (27*4 m) (36.7 m) (45.6 m) Spanish 1 7 Banks 23 43 Transect 37 27 '143 36 8 53 43.5% 97.5% S i l t S i l t P o int 0 9 Grey 0 73 Transect 6 10 3 32 2 27 2.4% 93.9% S i l t S i l t North 0 15 Arm 0 5 Transect 6 42 2 8 4 2 67.6% 72.8% S i l t • S i l t 9 7 0 20 1 2 5 7 4 27 1 1 15 0 1 89.6% 91*7% 86.2% S i l t S i l t S i l t 9 6 7 13 57 33 ii 16 10 19 37 23 13 7 36 99.7% 95.7% 94.7% S i l t S i l t S i l t 32 1 7 42 4 3 42 0 68 63 105 15 2 7 81.1% - 79.4% 88.4% S i l t S i l t S i l t ( 52 Table V, Catches of Lycodopsis p a c i f i c a per ten minute trawl at the Cape Lazo g u l l y . Data averaged over sampling i n November 1965, January 1966, and August-September 1966. SECTION DEPTH NUMBER SECTION DEPTH NUMBER (fm) 30 56 5 30 1 35 59 35 118 40 93 40 143 42 113 45 235 44 232 50 1250 30 0 6 30 1 35 208 35 10 40 201 40 75 45 127 50 197 30 135 7 30 7 35 72 35 113 40 178 40 178 45 474 45 293 50 334 35 264 8 40 221 40 257 45 389 45 146 50 319 53 s i g n i f i c a n t at the 95% l e v e l (Table VI), The r e s u l t s v e r i f i e d the hypothesis that Lycodopsis p a c i f i c a was not uniformly abun-dant over the t r a n s e c t s sampled. B a r t l e t t ' s t e s t f o r homo-geneity of variance ( S t e e l and T o r r i e , I960) was appli e d to the variance data from the three t r a n s e c t s , A chi-square value of 1,200 (2 d.f.) was not s i g n i f i c a n t at the 95% l e v e l , The t e s t v e r i f i e d the a d d i t i v i t y of the variance information, Subse-quently a n a l y s i s of variance over the three t r a n s e c t s combined was performed. Once again the above-mentioned hypothesis was accepted, A m u l t i p l e comparison technique developed by Scheffe (1953) was u t i l i z e d to t e s t the s i g n i f i c a n c e of d i f f e r e n c e s i n catches at•the various s t a t i o n s . This i s a system f o r con-s t r u c t i n g confidence l i m i t s f o r a l l imaginable c o n t r a s t s of an experiment employing a n a l y s i s of variance. I t s advantage l i e s i n the f a c t the comparisons are independent of each other. S i g n i f i c a n c e of a contrast i s judged by noting whether the con-fidence i n t e r v a l brackets a value of zero, I f , f o r each ex-periment we perform, we construct confidence l i m i t s , i n (1 -alpha) of these experiments a l l the confidence statements w i l l be c o r r e c t , and i n oC of the experiments one or more confidence statements w i l l be i n c o r r e c t . Alpha («•) i s the complement of the p r o b a b i l i t y l e v e l being used - here 0,95 (see Appendix, p. 81). D i f f e r e n c e s i n catches of Lycodopsis p a c i f i c a at the various depths and sediment types were compared for s t a t i s t i c a l s i g n i f i c a n c e using the technique (Table V I I ) . Catches at f i v e 54 Table VI, A n a l y s i s of variance of catch data f o r L. p a c i f i c a at the outer Burrard I n l e t experimental a r e a T * i n -d i c a t e s s i g n i f i c a n c e at the 95% p r o b a b i l i t y l e v e l ; ** i n d i c a t e s s i g n i f i c a n c e at the 99% p r o b a b i l i t y l e v e l ) , ANALYSIS OF VARIANCE DATA FOR THE THREE TRANSECTS Spanish Banks Source &tl'i.^. Sum Squares Mean Squares F - r a t i o Treatment 4 5.0371 1,1259 ( S t a t i o n s ) E r r o r 20 3.5188 0,1759 T o t a l 24 7.9259 6,4007* P o i n t Grey Source d*f. Sum, Squares Mean Squares F - r a t i o Treatment 4 3.6218 O.9054 ( S t a t i o n s ) E r r o r 20 2,4233 0,1211 T o t a l 24 6.0451 7»4764** North Arm Source d.f. Sum, Squares Mean Squares F - r a t i o Treatment 4 3*1991 0.7997 ( S t a t i o n s ) E r r o r 20 5.4129 0,2706 T o t a l 24 8,6120 2.9552* 55 s t a t i o n s , namely P5, N5, N20, SB20 and SB25 were found to be s i g -n i f i c a n t l y d i f f e r e n t (lower) than catches at the other ten s t a -t i o n s (Table 7). The. per cent s i l t ranged from Z,.k% to 94,7% at the f i v e s t a t i o n s . The depth range was 5 to 20 fm (9.2m-45,6m), These conclusions are based on a l l transect data. The variances i n catches d i f f e r e d from one transect to another. The F - r a t i o of the a n a l y s i s of variance c a r r i e d out on catches from North Arm transect i s q u i t e low (Table V I ) , Even though the a d d i t i v i t y of the t r a n s e c t variance i s proved by B a r t l e t t ' s t e s t (see above) divergent r e s u l t s are obtained depending on which variance data are used. For example, using data from the Spanish Banks and Point Grey t r a n s e c t s only, the contrast i s s i g n i f i c a n t , A number of combinations were tes t e d (Table V I I ) , In general, s t a t i s t i c a l t e s t s suggest r e j e c t i o n of the o r i g i n a l hypothesis. At outer Burrard I n l e t , aggregations of Lycodopsis  p a c i f i c a were not found to occur on sediments of a c e r t a i n p h y s i c a l nature as measured by per cent s i l t and per cent sand. In a d d i t i o n , diagrams r e l a t i n g catches of L, p a c i f i c a to s e d i -ment type (% s i l t ) and depth (fm) were constructed ( F i g s . 21 and 22). There i s no suggestion from these p l o t s that aggre-gations of L, p a c i f i c a are a f f e c t e d by these two f a c t o r s . A s t a t i s t i c a l approach was not adopted at the Cape Lazo study s i t e . F o l l o w i n g d i s c u s s i o n w i l l be l i m i t e d to sampling on the west side of the g u l l y * On the east slope, the hard bottom required sampling with a t r a w l equipped with " r o l l e r s " on the groundline. This type of t r a w l i s probably f a r l e s s e f f i c i e n t at c a p t u r i n g Lycodopsis p a c i f i c a than the standard t r a w l s u t i l -i z e d on the west slope. The catch data were averaged over the 56 Table V I I . Tests of s i g n i f i c a n t d i f f e r e n c e s between catches of L s p a c i f i c a at outer Burrard I n l e t transect s t a t i o n s . Contrasts according to the method of Scheffe ( 1 9 5 3 ) . CONTRAST SB5 vs S B 2 5 N25 vs SB25 N15 vs N20 SB5 vs P5 SB5 vs SB25 a l l SB, P vs N P15 vs SB15 SB20, SB25, P5, N5, vs remain-i n g s t a t i o n s SB20, SB25, P5, N5, vs remain-i n g s t a t i o n s N20 vs SB20, SB25, P5, N5 VARIANCE DATA USED A l l i n t e r - t r a n s e c t data North Arm, Spanish Banks data North Arm data Point Grey, Spanish Banks data Spanish Banks A l l i n t e r - t r a n s e c t data Po i n t Grey, Spanish Banks data A l l i n t e r - t r a n s e c t data A l l i n t e r - t r a n s e c t data A l l i n t e r - t r a n s e c t data SIGNIFICANCE (95% prob, l e v e l ) Not s i g n i f i c a n t Not s i g n i f i c a n t Not s i g n i f i c a n t S i g n i f i c a n t S i g n i f i c a n t Not s i g n i f i c a n t Not s i g n i f i c a n t S i g n i f i c a n t -S i g n i f i c a n t Not s i g n i f i c a n t Key to ab b r e v i a t i o n s : SB - Spanish Banks Transect P = Po i n t Grey Transect N = North Arm Transect 57 I rr h-LU I -3 2 UJ r -cr LU LU m 3 2 20 40 60 80 100 PERCENT SILT IN SEDIMENT Fig. 21. Catches of L. pacifica at outer Burrard Inlet related to sediment type. SAMPLING DEPTH Fig. 22. Catches of L. pacifica at outer Burrard Inlet related to sampling aepth. 58 three sampling times (Table V), i n d i c a t i n g the species was more abundant i n the bottom of the trough ( F i g , 23), Diagrams r e -l a t i n g L. p a c i f i c a to sediment type and depth (fm) were con-st r u c t e d ( F i g , 24 and 25), The p l o t s suggest that L, p a c i f i c a was more abundant at depths greater than 40 fm (73,2 m) where modal diameter of the sediment was l e s s than 80 microns and may be considered " s i l t " . D i s cussion of R e s u l t s Results at the two study areas i n d i c a t e two d i f f e r e n t en-vironments are present. At outer Burrard I n l e t , Lycodopsis  p a c i f i c a was captured i n high abundance on s e v e r a l sediment types, ranging from a s i l t - s a n d mixture to s o f t s i l t . At the Cape Lazo g u l l y the species was captured i n high abundance on s i l t . The premise of the preceding s t u d i e s i s that L« p a c i f i c a w i l l aggregate where s u i t a b l e i n f a u n a l food organisms are con-centrated, and where feeding morphology can operate most e f f i c i e n t l y . D iscussion of r e s u l t s , then, should i n v o l v e three t o p i c s : F i r s t l y , f a c t o r s i n f l u e n c i n g the " h a b i t a t pre-ference" of L, p a c i f i c a ; secondly, the p o s s i b i l i t y of d i r e c t n u t r i t i v e value of the sediments; and f i n a l l y , f a c t o r s i n f l u -encing the infauna, i n p a r t i c u l a r , sediment p r o p e r t i e s . Factors I n f l u e n c i n g Lycodopsis p a c i f i c a Temperature and s a l i n i t y are two major p h y s i c a l f a c t o r s that can a f f e c t the h a b i t a t preference of f i s h e s * In the pre-sent study, L. p a c i f i c a was found i n abundance over consider-59 Fig. 23. Average catches of L. pa cif ica in relation to modal grain diameter of sediments (in microns) at the Cape Lazo gully. Data from collections in November 1965, January 1966, and August-September 1966. ^ - 0 to 166 individuals per 10 minute trawl; © - 101 to 299 individuals per ten minute trawl; O - 300 individuals per ten minute trawl. 60 400 300 h 1250 I cr. I-200h 100 h cn LU a. cr LU co UJ < a: LU 5 IOOto250jj >80;J 70 60 50 MODAL DIAMETER OF SEDIMENT(microns) Fig. 2/*. Catches of L. pacifica at the Cape Lazo gully related to sediment type. 350 250 r-30 35 40 45 SAMPLING DEPTH (fm) 50 Fig. 25. Catches of L. pacifica at the Cape Lazo gully related to sampling depth. 61 able ranges of temperature and s a l i n i t y . At the Cape Lazo g u l l y , f o r example, bottom temperatures ranged from 7*02°C to 10.60°C, S a l i n i t i e s ranged from 28*79 %o to 30.42 % o . As outer Burrard I n l e t i s an estuarine environment, these para-meters may vary widely, The stage of the t i d e , f o r example, may a f f e c t the temperature and s a l i n i t y regimes at the shallow l o c a t i o n s . F j a r l i e (1950) encountered temperatures ranging from 8.90°C to 15.50°C, and s a l i n i t i e s ranging from 15%o to 30%o, In general, F j a r l i e found shallow s t a t i o n s have higher temperatures and lower s a l i n i t i e s than deeper s t a t i o n s at outer Burrard I n l e t . L. p a c i f i c a was found i n high abundance at both shallow and deep l o c a t i o n s . More hydrographic i n f o r -mation would be needed to determine the importance of tempera-ture and s a l i n i t y at both study areas. The recorded depth range of the species i s from j u s t be-low the i n t e r t i d a l zone ( B a y l i f f , MS, 1954) to over 200 fm (365.5 m) (Clemens and Wilby, 1961). Depth may not be im-portant f a c t o r a f f e c t i n g the h a b i t a t preference of the species. The s i t u a t i o n i s very complicated. At l e a s t three v a r i a b l e s may be c o r r e l a t e d with depth - sediment type, temperature, and s a l i n i t y . The r e l a t i v e importance of the f a c t o r s may vary from one l o c a t i o n to another. Habitat preference can vary with the l i f e h i s t o r y of the species. There i s some evidence from the present study which i n d i c a t e s age groups of Lycodopsis p a c i f i c a d i f f e r i n t h e i r h a b i t a t preference. For example, S t a t i o n s SB5 and N25 d i f f e r i n sediments. The sediments at SB5 contained much more sand 62 than d i d N 2 5 . The two s t a t i o n s cover a depth range of 20 fm ( 3 6 . 5 m)• Lycodopsis p a c i f i c a was captured i n high abundance at both s t a t i o n s . Length frequency polygons of i n d i v i d u a l s captured at the two s t a t i o n s show younger f i s h were caught more frequently at S t a t i o n N 2 5 than SB5 ( F i g . 2 6 ) . However, more sampling would be necessary to show and a g e - s p e c i f i c d i f f e r e n c e i n habitat-preference. P o s s i b i l i t i e s of D i r e c t N u t r i t i v e Value of Sediments Lycodopsis p a c i f i c a i n g e s t s sediments i n tra c e amounts. The species may pr e f e r h a b i t a t s r i c h i n some organic or i n o r -ganic c o n s t i t u e n t s . Some marine sediments may be of s i g n i f i -cant n u t r i t i v e value of a p a r t i c u l a r chemical i s associated with them. There i s l i t t l e i n f o r m a t i o n on the matter. Sheldon and Warren (1966) note that several species of crustaceans and f i s h e s i n g e s t sediments. The f i d d l e r crab (Uca spp.) has been shown to obtai n n u t r i t i v e m a t e r i a l from f i n e sediments ( M i l l e r , 1 9 6 1 ) . Sediment P r o p e r t i e s I n f l u e n c i n g Concentrations of Infauna The f a c t o r s i n f l u e n c i n g concentrations of the i n f a u n a l food organisms of Lycodopsis p a c i f i c a w i l l no* be considered, Sediment c h a r a c t e r i s t i c s i n p a r t i c u l a r w i l l be discussed. In the past i t has been assumed that standard g e o l o g i c a l methods d e s c r i b i n g sediments are u s e f u l i n st u d i e s concerning marine bottom fauna. As pointed out by Thorson (1957) t h i s i s probably true over wide ranges of p a r t i c l e s i z e , e.g., sand SPANISH BANKS TRANSECT 5fm. (9.1) June 9,1966 (n = 143 ) NORTH ARM TRANSECT 25fm. (45.6m) June 13,1966 (n=l05) A L 40 60 80 LENGTH 100 mm 120 140 160 F i g . 26. L e n g t h f r e q u e n c i e s o f L . p a c i f i c a c a p t u r e d a t t w o s t a t i o n s a t t h e ' o u t e r B u r r a r d I n l e t e x p e r i m e n t a l s t u d y a r e a . 64 versus s i l t . Recently, the usefulness of simple mechanical a n a l y s i s i n s t u d i e s of causal f a c t o r s a f f e c t i n g the benthos has been questioned by Buchanan (1963) working i n the North Sea and Longhurst (1959) working o f f West A f r i c a , Beanland (1940), Holme (1949). and Chapman (1949) suggest the fauna of the North Sea mud and sand communities, both t i d a l and s u b t i d a l , are l i m i t e d by sediment texture and/or p e r m e a b i l i t y , Webb (1958) showed the d i s t r i b u t i o n of l a n c e l e t s (Branchiostoma nigerience) was l i m i t e d by the pe r m e a b i l i t y of sand deposits, which r e -f l e c t s i n t e r s t i t i a l space. P e r m e a b i l i t y and p o r o s i t y may be estimates of p a r t i c l e surface area. The binding of n u t r i t i v e m a t e r i a l may be dependent on the a v a i l a b i l i t y of a la r g e sur-face area. The a v a i l a b i l i t y of n u t r i e n t m a t e r i a l i n sediments i s of importance f o r the feeding of i n f a u n a l organisms. I n t e r s t i t i a l space may a l s o be an important f a c t o r govern-i n g settlement of i n v e r t e b r a t e l a r v a e . Cancer magister mega-lopa l a r v a e were abundant i n food samples from Lycodopsis  p a c i f i c a captured at Spanish Banks (10 fm, 18,3 m) i n August 1966, No megalopa were found i n specimens captured at West Vancouver i n the same month. There i s probably a d i f f e r e n c e i n sediment types between the two s i t e s , The sediments at Spanish Banks (10 fm, 18,3 m) are probably of the c o r r e c t p h y s i c a l nature f o r the s e t t l i n g of C, magister l a r v a e , Wilson (1958) reviews the problems of determing s e t t l i n g s i t e s of i n v e r t e -brate l a r v a e , Cockbain (1963) worked i n the S t r a i t of Georgia and Juan de Fuca S t r a i t , He mentions that depth, median diameter of 65 sediment, and the number of benthic f o r a m i n i f e r a are apparently-r e l a t e d , but the r e l a t i o n s h i p between the sediments and the fo r a m i n i f e r a may be f o r t u i t i o u s . At outer Burrard I n l e t , a complicated estuarine system governs the de p o s i t i o n of s e d i -ments i n the area, Waldichuk (1953) and F j a r l i e (1950) show the "sediment cloud" d i s c h a r g i n g from the North Arm of the Fraser River can extend f a r i n t o Burrard I n l e t , The pattern of d e p o s i t i o n of s i l t from the sediment cloud may be of impor-tance to the i n f a u n a l i n v e r t e b r a t e s i n the food spectrum of Lycodopsis p a c i f i c a . Spanish Banks sand i s of d i f f e r e n t ( t e r -r e s t r i a l ) o r i g i n than that c a r r i e d onto the foreset beds of the North Arm (Mathews, 1967, pers, comm.), A l l s i l t i n outer Burrard I n l e t , however, i s probably of Fraser R i v e r o r i g i n . The s i l t may contain concentrations of elements of importance to i n f a u n a l organisms. There i s the p o s s i b i l i t y that p r e c i -p i t a t i o n of suspended sediment of a c r i t i c a l s i z e or mineral composition may occur i n an optimum area of the "sediment cloud" (Shepard, 1963). S t a t i o n s P5, N5, SB20, and SB25 may be outside the periphery of the optimum area, L. p a c i f i c a occurred i n low abundance at these s t a t i o n s . The Food Spectrum, Feeding Adaptations, and Aggregations  of Lycodopsis p a c i f i c a i n R e l a t i o n to Sediment Type An examination of the food spectrum of the species shows Lycodopsis p a c i f i c a i s c a t h o l i c i n i t s feeding h a b i t s (p. 29), A study of the feeding anatomy of L, p a c i f i c a i n d i c a t e s the species i s adapted to detect, remove, i n g e s t , and dig e s t i n -66 faunal i n v e r t e b r a t e s from sediments (p. i+7), I t was assumed that L, p a c i f i c a would aggregate where concentrations of s u i t a b l e i n f a u n a l food organisms would be found. The para-meters per cent s i l t and modal g r a i n s i z e ( i n microns) were used to describe sediments i n t h i s study. The r e s u l t s of ex-perimental t r a w l i n g at two study areas i n the S t r a i t of Geor-g i a i n d i c a t e that L, p a c i f i c a i s found i n abundance on a range of sediment types (p. 5 8 ) , Feeding aggregations of the species are apparently not l i m i t e d by g r a i n s i z e (sediment type) over the range encountered i n t h i s study. The species i s adapted to feed on a benthic i n f a u n a l community, the components of which may be l i m i t e d by sediment type. 67 SUMMARY Lycodopsis p a c i f i c a ( C o l l e t t ) 1879 (Zoarcidae) was studied at two l o c a t i o n s i n the S t r a i t of Georgia, B r i t i s h Columbia. The study period was from September 1966 to March 1967. Trawls were used as sampling devices. Sexual dimorphism i s present- The older males are l a r g e r than females. Males s t a r t to grow l a r g e r than females at approximately 170 mm i n length. The information supports the hypothesis that breeding occurs only i n l a r g e r i n d i v i d u a l s . Sexual maturity occurred i n older ( l a r g e r ) i n d i v i d u a l s between September and January. Lycodopsis p a c i f i c a has a remarkably small complement of mature eggs which develope from a l a r g e r complement of smaller ova, Although one z o a r c i d has been shown to be ovoviviparous, there i s no evidence f o r t h i s c o n d i t i o n i n •L* p a c i f i c a . Observations of the species from submersibles o f f C a l i f o r n i a i n d i c a t e L. p a c i f i c a has a reproductive behaviour p a t t e r n i n v o l v i n g p a r e n t a l care. Age was estimated by o t o l i t h s . Both males and females ranged up to f i v e years of age, Regression equations d e s c r i b -i n g growth f o r both sexes are presented. The length-weight r e -l a t i o n s h i p f o r the species was found to W = O.OOOOif^L^'°7897^ where V/ (weight) i s expressed i n grams, and L (length) i s ex-pressed i n m i l l i m e t e r s . At outer Burrard I n l e t , Lycodopsis p a c i f i c a feeds p r i m a r i l y on i n f a u n a l i n v e r t e b r a t e s of the Phyla Mollusca and Annelida and Subphylum Crustacea, The samples i n d i c a t e the food spec-trum may vary seasonally, from place to place, and with the age 68 of the f i s h . At outer Burrard I n l e t , the species was found to occur i n t r a w l s with members of 15 f a m i l i e s of f i s h e s . Invertebrates captured i n the t r a w l s were a mixture of ep i f a u n a l and i n f a u n a l organisms. The anatomy of s t r u c t u r e s associated with feeding i s de-s c r i b e d , Lycodopsis p a c i f i c a i s probably not s p e c i a l i z e d to feed on a p a r t i c u l a r sediment type. V i s u a l and "chemical" senses are probably important i n food-getting behaviour. I t was assumed that Lycodopsis p a c i f i c a would aggregate where high concentrations of infauna s u i t a b l e as food would be found. At outer Burrard I n l e t , the species occurred i n high numbers on seve r a l sediment types, ranging from s i l t - s a n d to s i l t . At the Cape Lazo g u l l y , L. p a c i f i c a was captured most commonly on a s i l t sediment. L, p a c i f i c a i s probably not r e -s t r i c t e d to c e r t a i n sediments by i t s feeding adaptations and l i k e l y i s capable of for a g i n g over a range of sediment types. Some sedimentary f a c t o r s a f f e c t i n g the infauna are discussed, and the u s e f u l l n e s s of simple mechanical a n a l y s i s of sediments i n benthic ecology i s questioned. 69 LITERATURE CITED Andriashev, A.P. 1937. A c o n t r i b u t i o n to the knowledge of the f i s h e s from the Bering and Chukchi Seas. Explorat. des mers de l'U.R.R.S, f a s c . 25, I n s t . Hydro,, Leningrad, pp 292-355, f i g s . 1-27. E n g l i s h t r a n s l a t i o n by L. Lanz with N.J. Wilimovsky i n U.S. Dept. I n t e r i o r , F i s h and W i l d l i f e Servece, Spec, S c i . Rept., F i s h e r i e s No. 145. 81 pp. B a l i , J.B., and C E . Bond,.. 1959. The b i g f i n eelpout, Aprodon  cortez i a n u s G i l b e r t , common i n waters o f f Oregon, Copeia (1) : 74-76. Barnes, R„D. 1963. Invertebrate zoology, W.B. Saunders Co., P h i l a d e l p h i a and London, 632 pp. B a y l i f f , W.S. 1954. Taxonomy and d i s t r i b u t i o n of northeast-ern P a c i f i c Zoarcidae. M.Sc. Thesis, Univ. of Washing-ton. 287 pp. Beanland, F.L. 1940. Sand and mud communities of the Dover estuary. J . Mar. B i o l , Assn. U.K., 24: 589-597. Berg, L.S. 1941. A c l a s s i f i c a t i o n of f i s h e s , both recent and f o s s i l , Trudy Zool. I n s t . Akad. SSSR ( 5 ) : 87-517. 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Aspects of deep sea bio l o g y , Hutchin-sons, London, 380 pp, MacKay, M.W, 1926, The d i g e s t i v e system of theeelpout (Zoar-ces a n g u i l l a r i s ) . B i o l . B u l l , Woods Hole, 5 6 : 8-9. Mcintosh, W.C. 1885. On the spawning of c e r t a i n marine f i s h e s . Annals and Mag. of Nat, H i s t o r y , Ser, 5, V o l . 15: 30-45. M i l l e r , D.C, 1961. The feeding mechanisms of f i d d l e r crabs, with e c o l o g i c a l c o n s i d e r a t i o n s of feeding adaptations. Zoologica, £16: 89-100, Moiseev, P.A. 1952, Some c h a r a c t e r i s t i c s of the d i s t r i b u t i o n of bottom and demersal f i s h e s of fa r - e a s t e r n seas, I z v e s t i i a Tiknookeanskovo Nauchno-issledovatelskova I n s t i t u t a Rybnovo K h o z i a i s t v a i Okeanografii, V o l . 37, p. 129-137. Rish. Res. Bd, Canada, T r a n s l , Ser., No. 94, 1952. 10 pp. Moore, G.A, 1950. The cutaneous sense organs of b a r b e l l e d minnows adapted to l i f e i n the muddy waters of the Great P l a i n s r e g i o n . Trans. Amer, Microscop. Soc. 6 Q : 69-95. N i k o l s k y , G.V. 1961. S p e c i a l ichthyology (Second Ed.). Translated f o r the Nat, S c i . Found., Washington, D.C. and the Smithsonian I n s t , by the I s r a e l Progr. f o r S c i . T r a n s l , , Jerusalem, 538 pp. 1963. The ecology of f i s h e s . T r a n s l . by L. B i r k e t t , Academic Press, New York. 325 pp. Okuda, T., and S, Sato. 1955« Fundamental i n v e s t i g a t i o n s on the marine resources of Matsushima Bay, I . On the bottom m a t e r i a l s of Matsushima Bay, B u l l . Tohoku Reg. Rish. Lab., (4): 187-277. P a r r i s h , B.B, 1958. Some notes on methods used i n f i s h e r y research, p. 151-178 i n Spec, Pub, No, I , I n t . Comm. f o r the Northwest A t l . F i s h e r i e s , H a l i f a x . R i c k e r , W.E. 1958. Handbook of computations f o r b i o l o g i c a l s t a t i s t i c s of f i s h populations. B u l l . F i s h . Res, Bd, Canada, No. 119, 300 pp. Scheffe, H, 1953. A method f o r judging a l l c o n t r a s t s i n the a n a l y s i s of variance. Biometrica, 40: 87-104. 72 Sheldon, R.W., and P.J, Warren, 1966. Transport of sediments by crustaceans and f i s h . Nature, 210: 1171-1172* Sheldon, R„, and T, Parsons, 1966, A p p l i c a t i o n s of the Coul-t e r Counter to Marine Research, F i s h , Res, Bd. Canada, Pac, Oceanogr, Group, Nanaimo, B.C., M,S, Rept. No. 214, 36 pp. Shelford, V,E, 1935. Some marine b i o t i c communities i n Puget Sound, E c o l . Mono., 5: 234-250, Shepard, F,J. 1963. Submarine geology (Second Ed,), Harper and Row, New York, 557 pp. S i e g e l , S. 1956. Non-parametric s t a t i s t i c s f o r the behavioural sciences. McGraw-Hill Book Co., 312 pp. S l i p p , J.W., and A.C. DeLacy. 1952. On the d i s t r i b u t i o n and ha b i t s of the v/attled eel-pout, Lycodes p a l e a r i s , Copeia, ( 1 ) : 201-203. S t e e l , R.D., and J.H, T o r r i e , I 9 6 0 , P r i n c i p l e s and procedures of s t a t i s t i c s , McGraw-Hill Book Co., Toronto, 4 8 I pp. Ting, R.Y. 1965* Ecology of demersal animals: problems i n . sampling. Ph.D. Thesis, Univ, of Washington (Abstract i n 1965 Res. i n F i s h e r i e s , C o n t r i b , No, 212, C o l l , of F i s h -e r i e s , F i s h , Res. I n s t , , Univ, of Washington, S e a t t l e ) , Thorson, G, 1957* Bottom communities i n Hedgpeth, J.W,, (ed,), T r e a t i s e on Marine Ecology and Paleoecology. Geol, Soc, Amer, Mem, 76, V o l , I , Ecology. Verwey, J . 1949- Habitat s e l e c t i o n i n marine animals. F o l i a Biotheor., S e r i e s B, No, 4: 1-22. Vladykov, V.D, 1956, Fecundity of speckled t r o u t (.Salvelinus  f o n t i n a l i s ) i n Quebec Lakes, J , F i s h , Res, Bd, Canada, 13: 799 rB41. Waldichuk, M* 1953» Oceanography of the S t r a i t of Georgia. I l l , Character of the bottom. F i s h , Res, Bd, Canada, Pac. Coast Sta., Prog, Rept, No, 95- 59-63. Webb, J,E, 1958. The ecology of Lagos Lagoon, V. Some p h y s i c a l p r o p e r t i e s of lagoon deposits, P h i l , Trans. Roy, S o c London (Ser a B) 241: 307-419. White, H.C, 1940. The n e s t i n g and embryos of Zoarces a n g u i l -l a r 1 s , J , F i s h * Res, Bd, Canada, 4: 337-338. Wilson, D:P, 1958, Some problems i n l a r v a l ecology r e l a t e d to the l o c a l i z e d d i s t r i b u t i o n of bottom animals, pp. 87-103 i n Buzzati-Traverso, A.A., (ed,), P e r s p e c t i v e s i n Marine Biology, Univ, C a l i f o r n i a Press, 621 pp, 73 APPENDIX Ik Age and Growth Studies Subsampling Techniques From each of the 17 samples obtained over the study period i n outer Burrard I n l e t , 20 f i s h were taken f o r age estimation by means of o t o l i t h s . Age determinations were made u n t i l two consecutive readings agreed. Fo l l o w i n g the s t r a t i f i e d subsampling technique o u t l i n e d .by Ketchen (1950), the f i s h were categorized by sex and by f i v e m i l l i m e t e r l e n g t h group. Because of mesh s e l e c t i o n a l l length (and therefore age) groups were not represented i n samples from the commercial shrimp v e s s e l catches. Supplemental data were obtained from c o l l e c t i o n s made with the experimental t r a w l s . R e s u l t s A t o t a l of 236 (129 males and 107 females) age estimations were u t i l i z e d under the s t r a t i f i e d subsampling scheme. Ages ranged up to f i v e years f o r both sexes, Mean length at age values are p l o t t e d i n Text F i g . 12 and are shown i n t a b u l a r form i n Appendix t a b l e s I and I I , "Translucent" vs "Opaque" Zones and Temperature The use of o t o l i t h s i n age and growth stud i e s i n v o l v e s the important assumption that the annular r i n g s are deposited sea-s o n a l l y . That i s , i t i s assumed there have been no environmen-t a l or p h y s i o l o g i c a l c o n d i t i o n s throughout the f i s h e s * l i f e that would cause a recognizable r i n g to be formed other than seasonal v a r i a t i o n s i n temperature, etc, "Translucent zone" r e f e r s to 75 Table I I , Age (years) - Length (centimeters) t a b l e f o r female L. p a c i f i c a c o l l e c t e d at the outer Burrard I n l e t study area, Data obtained by s t r a t i f i e d subsampling according to the method of Ketchen (1950). I I I I I IV V 6 7 3 8 11 9 5 10 2 11 3 3 12 7 7 13 2 7 1 lk 7 k 15 1 9 16 k k 1 17 6 5 2 18 1 6 19 2 3 20 21 22 23 2k T o t a l 33 25 27 18 3 Mean Length (cms) 9.6 12,3 15.8 17.4 17.6 Std, Dev, 1,90 2o78 1,54 1.05 0 76 Table I f Age (years) - Length (centimeters) t a b l e f o r male h* p a c i f i c a c o l l e c t e d at the outer Burrard I n l e t study area. Data obtained by s t r a t i f i e d sub-sampling according to the method of Ketchen (1950), I I I I I IV V 6 7 4 8 13 9 4 10 l l 11 5 4 12 3 6 1 13 1 4 2 14 9 0 15 2 8 1 16 2 7 3 0 17 3 6 0 18 3 5 2 19 1 6 1 20 2 k 3 21 k 2 22 0 4 23 0 24 2 25 T o t a l 31 28 27 30 13 Mean Length (cms) 9.1 13.1 16,1 18,8 20.0 Std. Dev. 1.78 1.55 1.94 2,09 2,08 % FREQUENCY X TJ 0 ro M i 01 H - ' c+ g ro ro ro D. > C TJ 1 TJ H* • H* 3" • O M (0 O c+ ro a a> o c c+ ro -i ro o ro 3 o < ro 3 cr i ro ro 1 >a c t—< ro vO 3 o o ko O t-t <. ro If 3 • cr. ro In - - o o -3 ro a TJ ro 3) C IU ro Q. o a ST cu o ct- t—1 •-4 3" C + 3" TJ » M 3 ro u o TJ O S c K> ro o ro a US ro 02 AON £030 £2 030 6"NVP l£NVP OlddV « oi3Nnn -t'ATIP i2Ainr 8 9nv 8Id3S Wld3S 21100 £IA0N -0 0 O 5 TEMPERATURE °C (HOLLISTER I960) LL 77 concentric areas on the o t o l i t h where the pr o t e i n : c a l c i u m r a t i o i s low and therefore appears white under d i r e c t l i g h t . Such an area would be r e p r e s e n t a t i v e of r a p i d growth. An "opaque zone" r e f e r s to an area of high p r o t e i n : c a l c i u m r a t i o ; i t appears dark, and represents a period of reduced growth. This f o l l o w s the terminology of I r i e (i960) whose experimental work v e r i f i e d the supposition that the r i n g s of o t o l i t h s may be caused by temperature-dependent phenomena. The percentage of o'toliths i n each sample of 20 whose outer perimeter consisted of an opaque zone was noted. These data are shown g r a p h i c a l l y i n Appendix F i g , 1, Also shown i n the f i g u r e i s the annual temperature f l u c t u a t i o n t y p i c a l of B.C. c o a s t a l waters (data from H o l l i s t e r , i 9 6 0 ) . I t would appear we are j u s t i f i e d i n counting the opaque zones as annual phenomena. They are l a i d dov/n i n winter months when the en-vironmental temperature of L. p a c i f i c a i s lowest. 78 Species Composition of Fishes Caught i n Trawl Hauls ( a f t e r Berg, 1941; F a m i l i e s i n A l p h a b e t i c a l Order) F, Agonidae h&onus acipenserinus F, Bathymasteridae Bathymaster signatus RonquiTus j o r d a n i F. Batrachoididae P o r i c h t h y s notatus F« Bothidae C i t h a r i c h t h y s sordidus C i t h a r i c h t h y s stigmaeus F. Chimaeridae Hydrolagus c o l l e i F, Clupeidae Clupea p a l l a s i i F. Cottidae Leptocottus armatus  Radulinus a s p e r e l l u s  Dasycottus s e t i g e r F. Embiotocidae Cymatogaster aggregata Damalichthys vacca F : Gadidae Theragra chalcogrammus  Gadus macrocephalu s  Microgadus proximus F. Gobiidae Lepidogobius l e p i d u s MIIH 1111 Will « • » » • « • ! |fc UllllPIIII 1MB—»— KHMmlMHMW I I I C l e v e l a n d i a i o s F, Hexagrammidae Qphipdon elpngatus  Hexagrammos""stelleri F, I c e l i d a e I c e l i n u s t e n i u s F, Osmeridae Spirinchus d i l a t u s F» Pleuronectidae Atheresthes stomias  Eopsetta j ordani Glyptocephalus' zachirus  Hipppglossoides elassodon I o p s e t t a i s o l e p i s ~~ Lepidopsetta b i l i n e a t a Lyopsetta e x i l i s  Microstomus p a c i f i c u s Parophrys ve t u l u s P l a t i c h t h y s s t e l l a t u s  P s e t t i c h t h y s melanostictus F« Psychrolutidae Psychrolutes paradoxus F.... Rajidae Raja r h i n a F« Scorpaenidae Sebastodes maliger F. Squalidae Squalus acanthia F, Stichaeidae Lumpenus s a g i t t a , P o r o c l i n u s r o t h r o c k i 79 Invertebrates Taken i n Trawl Hauls ( a f t e r Barnes, 1963; and B o r r a d a i l e and P o t t s , 1963). Phylum Coelenterata Class Anthozoa Subclass Zoantharia Order C e r i a n t h a r i a Metridium spp. Phylum Platyhelminthes C l a s s T u r b e l l a r i a Order P o l y c l a d i d a Phylum Arthropoda Subphylum Crustacea C l a s s Malacostraca Order Isopoda Order Decapoda Suborder Natantia Section Caridea Gragon communis  Pandalopis d i s p a r  Pandalus b o r e a l i s  Pandalus p l a t y c e r o s  Pandalus hypsinotus  Pandalus danae  Paracrangon echinata  S p i r o n t o c a r i s hoimesi 8 0 Suborder Reptantia Section Macrura Cancer magister  Cancer oregonensis  Chronoecetes b a i r d i Section Anomura Dagurus spp. Munida quadrispina Phylum Mo'llusca C l a s s Gastropoda Subclass Opistobranchia Order T e c t i b r a n c h i a Order Nudibranchia Phylum Echinodermata Class Asteroidea L u i d i a f o l i o l a t a  P i s a s t e r b r e v i s p i n i s C l a s s Holothuroidea F. Synaptidae 81 O u t l i n e of Scheffes (1955) Technique of M u l t i p l e Comparisons i n A n a l y s i s of Variance Treatment means are assigned "contrast c o e f f i c i e n t s " (c. v a l u e s ) . Each contrast i s defined as 0 = 5 L C ; « K J where ^ C , ' = 0 S 2 mates N with -— estimating, i . e . , variance on a "per r e p l i c a t e " n i 2 s c a l e . S i s e r r o r mean square from the a n a l y s i s of variance. K 2, Z p * C^ ' H has variance of £TC; ; t h i s may be estimated from S L . The value "S " i s now obtained from tables of the F - r a t i o used i n a n a l y s i s of variance, S'"' = (^-^J) f ^ ^ - l ^ - l ) ' where t i s the number of treatments, and r i s the number of r e p l i c a t e s . In t h i s experiment, treatments are sampling stations. Confidence l i m i t s are constructed; the confidence statement i s as below: ^ i s the complement of the p r o b a b i l i t y l e v e l being used -here 0.95. 

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