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UBC Theses and Dissertations

Age, growth and maturity studies on the Pacific anchovy (Engraulis mordax) from the coast of British… Pike, Gordon Chesley 1951

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AGE,  GROWTH AND MATURITY STUDIES ON THE  P A C I F I C ANCHOVY ( E n g r a u l i s THE  rnordax)  FROM  COAST OF BRITISH COLUMBIA  by  GORDON CHESifLEY P I K E  A  THESIS SUBMITTED IN PARTIAL FULFILMENT OF  "  THE REQUIREMENTS FOR THE DEGREE OF MASTER Ofe ARTS. 1  in  We a c c e p t  this  t h e Department .of Zoology.  thesis  Standard required  as c o n f o r m i n g t o t h e  from candidates f o r the  d e g r e e o f MASTER OF ARTS.  Members o f t h e D e p a r t m e n t o f Zoology The  University  of British  April,  1951.  Columbia  ABSTRACT ' '  The occurs of  In l i m i t e d  from commercial Age  scale by  of  by  readings.  the  the  by 157 5  and  millimetres females 7  years.  majority of  or  length  two  an  t o be  of f i s h  age  of t h i s  years  19^7  species  168  selected  1951•  to  based c h i e f l y  on  was  the  of  method  10?,  of  105,  126,  same a g e s .  Maximum s i z e  of 6 y e a r s .  t a k e n i n the  i s f o u n d to be The  153  and  153 of  an  age  of  millimetres,  incoming y e a r  commercial catches  and  4,  and  millimetres, representing  o f males  149,  3,  2, 146  each  supported  140,  1,  I38,  In  is  128,  by  facilitated  dominant y e a r c l a s s e s of  the  checked  frequencies  lengths  the  small  summer months.  c a l c u l a t e d f o r females at  f o r males a t  class  are  2 or 3  years  age. Maturity  m e t e r s show t h a t in  of  Average  Maximum s i z e  representing  inlets  samples randomly  studies are  average l e n g t h s  i s found  the  The,reliability  m i l l i m e t r e s are years;  maturity  during  use  p r e s e n c e o f one  scale readings.  b a y s and  f r e q u e n c y d i s t r i b u t i o n s and  The  commercial c a t c h .  the  s p r i n g and  a n a l y s i s of  growth  length  the  g r o w t h and  catches  and  mordax G-irard,  C o l u m b i a where i t s u p p o r t s a  age,  c a r r i e d out  analysis  i n most o f  fishery during  study of the  was  anchovy, E n g r a u l i s  numbers  southern B r i t i s h  purse-seine A  Pacific  ^  s t u d i e s b a s e d on  spawning o c c u r s  southern B r i t i s h Columbia  measurements o f  i n most o f the  in late  ova  b a y s and  J u n e , J u l y and  diainlets  August,  The m a j o r i t y some may  o f f e m a l e s mature  mature  a p p e a r s to b e females of a l l March. size  in their  similar.  in their  first  year.  Growth  The s i t u a t i o n  o f the o v a b e g i n s  s i z e s and f r o m a l l  By J u n e the m a j o r i t y  localities  to s p a w n i n g .  given that multiple  s p a w n i n g s o c c u r and  size  i s m a t u r e d and  ing  ova a r e c a r r i e d  over  into  i n February  i n turn  and  three  Evidence i s each o f these  spawned.  succeeding years.  a v e r a g e o f 144,000 eggs a r e spawned each y e a r .  that  f o r males  i n adult  o f f e m a l e s have m a t u r e d  g r o u p s o f eggs p r e p a r a t o r y  g r o u p s o f eggs  second y e a r , but  No  matur-  A minimum  i n t h r e e o r more b a t c h e s  TABLE OF CONTENTS Page . I  Introduction. Distribution  of Engraulls  The A n c h o v y F i s h e r y II  2  of Materials  it-  T r e a t m e n t o f Samples Age and Growth  .5  Studies  Length Frequencies  IV  7  Scales  12  Sex R a t i o  15  Weight-length Relationship  16  Maturity  Studies  Methods  18  Growth o f the R i p e n i n g Frequency  Ova  Length a t F i r s t The  VI VII VIII  21  o f Spawning and  Number o f E g g s Spawned  V  1  Methods a n d M a t e r i a l s Collection  III  mordax  Maturity  23 30  Spawning S e a s o n  31  Spawning L o c a l i t i e s  33  Summary and C o n c l u s i o n s  35  Acknowledgements  38  Literature  39  Appendix  Cited  k2  FIGURES  1.  Length  frequency  female  c u r v e s f o r male  ( l b ) anchovy taken  ( l a ) and  for  in successive  months o f t h e y e a r t o i l l u s t r a t e  the  pro-  g r e s s i o n o f a g e - g r o u p modes* 2.  Growth c u r v e s f o r male and on the  3.  Ova  female  anchovy  based  t h e p r o g r e s s i o n o f a g e - g r o u p modes t o show s e a s o n a l and  annual growth  diameter frequency curves  pattern.  showing growth  of  a n c h o v y eggs t o m a t u r i t y . 4.  Percentage of  5.  Ova  of adult  m a t u r i t y by  diameter taken ova  female  anchovy  In e a c h  stage  months.  frequency curves  in July,  1948;  sizes.during  f o r 14 f e m a l e  anchovy  showing the g r o u p i n g o f  the  early  spawning  period.  TABLES Page 1.  2.  Annual  C a t c h and  In  British  to  19^7.  Disposition British  Columbia  Instantaneous mordax.  Columbia  o f 1946  Marketed 3.  Landed Value  o f Anchovy  f o r the years  Anchovy C a t c h  1939  In  showing q u a n t i t y and  Value. Growth Rates  for Engraulla  TABLES  (cont'd) Page  1+.  Analysis  of length frequencies of  samples o f a n c h o v y f r o m 191+7  21  catches 10  by the use o f p r o b a b i l i t y p a p e r . 5.  C o m p a r i s o n o f Modes ( f i g . 2) (table  and Means  IV) f o r Second Y e a r Anchovy 11  by Months. 6.  C o m p a r i s o n o f Modes  ( f i g . 2)  and Means  ( H a r d i n g ' s P r o b a b i l i t y Method) 2nd 7.  1st,  of  and 3 r d Y e a r A n c h o v y f o r J u n e .  12  Mean L e n g t h s o f A n c h o v y C a l c u l a t e d f r o m S c a l e R e a d i n g s o f 353 . F i s h b y Sex, Month  8.  and Age.  Sex R a t i o o f A n c h o v y b y Months; a l l localities  9.  lij.  Length-weight R e l a t i o n s h i p during  l6  combined. o f Anchovy  the S p r i n g and Summer months  17  o f 191+7. 10.  R a t i o s o f Numbers o f E g g s i n e a c h M a t u r i n g Group b y S t a g e s i n 191+7  and 25  19i+8 S a m p l e s . 11.  Number o f M a t u r i n g E g g s i n t h e Gonads of  12.  A d u l t Female D u r i n g  29  July.  Number and P e r c e n t a g e o f M a t u r i n g Anchovy by L e n g t h i n March, May  and J u n e .  Female  April, 31  INTRODUCTION  The species  study  i s fundamental  h i s t o r y , and in  the  abundance o f  Engraulls  age,  g r o w t h and  mordax.  The  life  i n v e s t i g a t e d i n the  r a n e a n and b e e n done  maturity  understanding  information  is directed in this  k n o w l e d g e on  g r o w t h and  t o the  for yielding  relative  emphasis  been  o f age,  on  successive study  of  the year  N o r t h Sea,  North America.  the l i f e  s p e c i e s has  been d e r i v e d  incidentally  t o the  s p e c i e s and  i s fragmentary.  growth or m a t u r i t y m a i n l y on  the  C o l u m b i a and part  of  therefore  Distribution  from  Pacific  In  numbers as  f o u n d up and  of to  the  United  States  moves i n  schools.  coast  to B r i t i s h species  f a r north  t h r e e hundred miles  typically  its  age,  i s based  samples  species only  the P a c i f i c  C o l u m b i a the  coast  study  this  other  from  British  i n the  northern  1854,  a n c h o v y , E n g r a u l l s mordax G i r a r d  waters of B r i t i s h  the  the  of  of  mordax  Lower C a l i f o r n i a  rather limited  catch  has  Coast  accounts of  This  Mediter-  h i s t o r y of  study  have  0  i n abundance a l o n g  southern  commercial  considers  of Engraulls  The occurs  analysis of  i t s range  published  have y e t a p p e a r e d .  the  the P a c i f i c  knowledge o f  No  anchovy,  l i t t l e work  Previous  basic  Engraulids  Zuyder Zee,  E n g r a u l l s mordax o f  Primary  o b t a i n i n g of  of various  the  variation  classes.  r e c e n t l y In A u s t r a l i a n w a t e r s , b u t in studying  of  o f the P a c i f i c  histories  fish  its life  extent  towards the  maturity  o f any  to  Columbia.  appears  America In  the  i n b a y s and  as Ogden C h a n n e l .  i t occurs out  of North  Inlets Along  i n l a r g e numbers and  sea.  The  fish  is  is pelagic  In h i s study of  California,  Pacific and  Hubbs ( 1 9 2 5 ) r e c o g n i z e s  a n c h o v y : a "bay" s u b s p e c i e s ,  two s u b s p e c i e s  of the  E n g r a u l l s mordax nanus  t  E n g r a u l l s mordax mordax.  spawns n e a r t h e e n t r a n c e  sea f o r the w i n t e r .  off  o f f the coast  The f o r m e r  In San F r a n c i s c o Bay In t h e warmer months o f t h e y e a r  when I t a p p a r e n t l y to  o f anehovy p o p u l a t i o n s  an " o c e a n " s u b s p e c i e s ,  occurs  2 -  the coast  The "ocean"  of C a l i f o r n i a .  subspecies  I s shown t o spawn  Variations in certain  c h a r a c t e r s o f the s p e c i e s throughout three p o p u l a t i o n s which f a i l  a n d l a t e r moves o u t  meristlc  i t s r a n g e show a t l e a s t  to i n t e r m i n g l e c o m p l e t e l y  (McHugh,  1950): a n o r t h e r n p o p u l a t i o n ranges from B r i t i s h Columbia t o northern  California;  California lation  a second p o p u l a t i o n  and i n n o r t h e r n B a j a , C a l i f o r n i a  i s found  i n central  Common names are  "California  anchovy". accepted  i s found  and s o u t h e r n  anchovy",  "Pacific  and a t h i r d  Baja,  used to designate  i n southern  California.  E n g r a u l l s mordax G - i r a r d  anchovy", and  "northern  The l a t t e r name has b e e n r e c o g n i z e d and p o p u l a r l y f o r many y e a r s .  Recently,  however, t h e name  a n c h o v y " h a s b e e n a d o p t e d by t h e A m e r i c a n F i s h e r i e s Committee o n Common and S c i e n t i f i c Names The  f o r the P a c i f i c  t h e B r i t i s h C o l u m b i a c o a s t s i n c e 1939;  value 1939 on  "Pacific  Society's  (19^8).  Anchovy F i s h e r y A small fishery  on  popu-  of the fishery t o 19^7  i n Table  a n c h o v y has  t h e m a g n i t u d e and  a r e shown f o r t h e e i g h t y e a r I.  developed  Almost a l l the f i s h i n g  p e r i o d from i s carried  d u r i n g t h e summer months when l a r g e s c h o o l s o f a d u l t  appear  In t h e i n l e t s .  During  the w i n t e r o n l y  small  fish  schools  - 3o f young  individuals  appear.  in  the  catches  shown i n t h e  of  the  fishery  and  The  marKed y e a r l y f l u c t u a t i o n s  table  give reason  reflect  to expect  the  sporadic  that i t w i l l  v e l o p f a r beyond  i t s present  proportions unless  s h o u l d r e v e a l an  extensive offshore population.  nature not  de-  investigation  I  TABLE  A n n u a l C a t c h and L a n d e d V a l u e o f Anchovy In B r i t i s h Columbia f o r t h e y e a r s 1939 t o 1947 YEAR  QUANTITY CWT 1  1939 I94O 1941 1942 1943  19,320 74,435 136,727 : 79,900 1,407 Off  the  VALUE  , -I  3,864 21,046 62,336.  39,846 703  s p e c i e s as  ing  into a major f i s h e r y  latent capable  five  million  (1945),  that  1946  fresh  "of the  Columbia anchovy are used the f i s h e r y  c a t c h as  Canada,  few  be  develop-  summarized  remaining seems  for  canning.  a r e r e p r e s e n t e d by  the  dis-  fish  market  i n the  o i l has  Attempts  t o market  II,  for bait California  I n t h e same and  two  in both  the  special products  year,  million  fishery.  been discouraged  government r e g u l a t i o n s d u r i n g r e c e n t y e a r s and  may  of  of  mainly  shown i n T a b l e  d u c t i o n o f a n c h o v y t o m e a l and  States  in  Importance  c o a s t , t h e anchovy  pounds o f a n c h o v y were u s e d  pounds f o r the  9,150 11,343 21,470 71,450  the g r e a t e s t r e t u r n s " .  s u p p l i e d by  p o s i t i o n of the  The  b e e n r e c o g n i z e d and  r e s o u r c e s of the P a c i f i c  of y i e l d i n g  products  has  of Walford  In B r i t i s h The  12,200 15,000 25,400: 28,580  VALUE $  an u n t a p p e d r e s o u r c e w i t h p o s s i b i l i t i e s  statement fishery  1944 1945 1946 1947  t h a t o f the p i l c h a r d .  the  the  QUANTITY CWT.  c o a s t o f the U n i t e d S t a t e s a n c h o v y o c c u r  q u a n t i t i e s approaching  in  YEAR  Re-  by United such  as  marinated  a n d c u r e d a n c h o v y , o r a n c h o v y p a s t e s have n o t b e e n  particularly European  s u c c e s s f u l because  in  Columbia  small seine nets.  anchovy a r e f i s h e d  inches to  e x c l u s i v e l y by  The s e i n e s a r e a p p r o x i m a t e l y 150  5/l6th i n c h e s , 6 t h o u s a n d t h t o 12 t h o u s a n d t h  and  hung  " i n " about  for  canning a r e packed  portation  20 p e r c e n t i n 25 f a t h o m . i n 400 pound  to t h e cannery.  necessitates  iced  The d e l i c a t e  fathoms  Meshes a r e .5/8th  l e n g t h a n d 1,000 t o 1,400 meshes i n d e p t h .  fish  imported  products. In B r i t i s h  using  o f c o m p e t i t i o n from  Fish  weight  t o be u s e d  f i s h boxes f o r t r a n s physical  nature o f the  extreme c a r e i n h a n d l i n g . TABLE I I  D i s p o s i t i o n o f 19^6 A n c h o v y C a t c h i n B r i t i s h Showing Q u a n t i t y a n d M a r k e t e d V a l u e PRODUCT  ,  QUANTITY  29,946  Canned  v  MARKETED VALUE ( $ )  610,586  cases  24 t o n s  Meal  35,625  Oil II.  Columbia  1,680  pounds  2,840  METHODS & MATERIALS  Collection of Material The forty  m a t e r i a l used  samples o f c o m m e r c i a l  y e a r s 19^7 t o 1950 in  cold  Canada.  Jervls  inclusive.  Smiths  Sampling  was c a r r i e d Research  i n c l u d e d B a r k l e y Sound, B u r r a r d  Inlet,  from  The u n s e l e c t e d s a m p l e s were k e p t  I n t h e employ o f t h e F i s h e r i e s  F i s h i n g areas  Inlet,  s t u d y was o b t a i n e d  catches landed a t Vancouver d u r i n g the  storage p r i o r to treatment.  the author while of  for this  S e c h e l t I n l e t , D e p a r t u r e Bay  out by Board Inlet,  - 5 and  other waters  A complete Appendix  list  a d j a c e n t t o and i n c l u d i n g o f samples  the S t r a i t  by date and l o c a l i t y  taken p r i o r  t o 19^7 were u s e d  s t u d y b u t t h e m a j o r i t y were r e j e c t e d b e c a u s e i n e a c h sample,  vation. growth  i s given i n  A. Some samples  numbers  of Georgia.  studies.  Treatment  of insufficient  l a c k o f d a t a on l o c a l i t y  Some o f t h e more r e l i a b l e These a r e l i s t e d  samples  in this  o r improper  were u s e d  preser-  i n t h e age and  i n the Appendix.  o f Samples The  material  from commercial  c a t c h e s i s taken t o be r e -  p r e s e n t a t i v e o f t h e p o p u l a t i o n s o f anchovy waters of B r i t i s h  Columbia.  a p r e f e r e n c e on t h e p a r t  I n h a b i t i n g the c o a s t a l  Some s e l e c t i o n may o c c u r b e c a u s e o f  o f the f i s h e r m e n f o r l a r g e r  s e l e c t i o n w i t h i n a school  seems u n l i k e l y b e c a u s e  schools, but  of the f i n e  mesh o f t h e s e i n e s . The  method o f s a m p l i n g c o n s i s t e d o f l e n g t h and w e i g h t  measurements o f 100 t o 200 f i s h E x c e p t where s a m p l e s  c o n s i s t e d o n l y o f immature f i s h  were r e c o r d e d s e p a r a t e l y .  From e a c h f u l l  t a k e n a t random f o r p r e f e r r e d 20 f i s h , lected  from each commercial  scale- and o t o l i t h  sample,  catch. the sexes  20 f i s h  were  treatment; from each o f these  samples  were t a k e n , a n d o v a r i e s  col-  from a l l females. L e n g t h measurements were made t o t h e n e a r e s t  millimetre  u s i n g a measuring board standardized  f o rherring  Pacific  t h r o u g h o u t t h e s t u d y were  Biological  Station.  Lengths  measured from t h e t i p o f t h e p r o t r u d i n g the  silvery  studies a tthe  s n o u t t o t h e end o f  a r e a on t h e c a u d a l p e d u n c l e a f t e r t h e s c a l e s h a d b e e n  s c r a p e d away.  No a l l o w a n c e was made f o r s h r i n k a g e i n any o f  - 6 the  samples.  Shrinkage  due t o f r e e z i n g  but  s h r i n k a g e o c c u r r i n g d u r i n g t h e I n t e r v a l between c a p t u r e and  f r e e z i n g may b e c o n s i d e r a b l e .  Apparent  f o u r m i l l i m e t r e s have b e e n c a l c u l a t e d to  a day a f t e r  capture  (Templeman,  i s probably  negligible,  s h r i n k a g e s o f two t o  f o rCapelin several  hours  1948).  W e i g h t measurements were t a k e n t o t h e n e a r e s t gram using a Chatillon cent  formalin  from  each  Scale  fish  O v a r i e s were p r e s e r v e d i n 10 p e r  vials.  Two o r more s c a l e s were  a n d p r e s e r v e d d r y b e t w e e n two m i c r o s c o p e  r e a d i n g s were made u s i n g a P r o m a r a p p a r a t u s .  i n paper  e a c h o f t h e 20 f i s h  envelopes.  roscope with d i r e c t Age of  scale.  i n individual  were taken from dry  spring  Readings  fore  used  slides.  Both  otoliths  sample and p r e s e r v e d  were made u s i n g a b i n o c u l a r  and growth s t u d i e s a r e based  chiefly  on t h e a n a l y s i s  S c a l e readings proved  t o be  f o r age d e t e r m i n a t i o n i n many c a s e s a n d a r e t h e r e -  o n l y as checks  on t h e l e n g t h f r e q u e n c y method a n d t o  determine  maximum a g e s .  B e c a u s e o f t h e method u s e d  otoliths,  i t was f o u n d n e c e s s a r y t o r e j e c t  determination caused  since drying  104  the o t o l i t h s  the t r a n s l u c e n t w i n t e r rings Maturity  ovaries  from  fish.  mic-  light.  length frequency d i s t r i b u t i o n s .  unsatisfactory  i n each  taken  studies  o v e r 500 f i s h ,  for preserving  t h i s m a t e r i a l f o r age  over a p e r i o d  o f time  t o become opaque a n d o b s c u r e .  a r e based  on d e t a i l e d  examination o f  and o v a d i a m e t e r measurements  from  - 7 III. Length  AGE  AND  GROWTH STUDIES  Frequencies A preliminary a n a l y s i s of length frequency  u t i o n s of  i n d i v i d u a l a n c h o v y c a t c h s a m p l e s shows t h a t  composed o f one these  o r more d i s c r e e t  l e n g t h g r o u p s r e p r e s e n t age  frequency  c u r v e s was  available.  Females  plotted i n each  m a l e s , t h e r e f o r e the sexes study.  A  study  demonstrate  T h i s was fishery  series  not  In o m i s s i o n s  The  one  the  s e p a r a t e l y throughout  the  f r e q u e n c i e s are intervals  i n which sexes  y e a r to  to  indicate  In r e p r e s e n t i n g g r o w t h t o h a v e y e a r f o r a l l age  classes.  seasonal nature of  yearns  6,625  by  to  year.  fish  year,  the r e s u l t i n g  were n o t d i s t i n g u i s h e d  the  months, or  and  two  samples a r e t h e r e f o r e modes.  l b show l e n g t h f r e q u e n c y  grouped and  i s used  samples and  the d o m i n a n t  data representing  was  l o n g e r than  y e a r r e p r e s e n t e d o n l y one  d a t a f o r each  F i g u r e s l a and  metre c l a s s  of l e n g t h  of samples f o r c e r t a i n  s e p a r a t e l y to p r e s e r v e  from  a series  slightly  from  o f s a m p l e s f r o m one  l e n g t h groups.  in  are t r e a t e d  desirable  f r o m any  Length  sample were  t h e y e a r and  b e c a u s e samples  structed  show t h a t  month In w h i c h d a t a  p o s s i b l e , hoiirever, as t h e  resulted  treated  f o r each  age-group composition of the  I t w o u l d be complete  classes,  each i s  To  o f the modal p r o g r e s s i o n w i t h time  growth rate throughout  a  l e n g t h groups.  distrib-  from  58  month and  curves catch  sex  consamples.  In 3  curves graphed.  milli-  Samples  a r e entered as d o t t e d  lines  figure l a . Lines  Joining  the  show a p r o g r e s s i o n t h r o u g h o u t  a g e - g r o u p modes i n f i g u r e s l a and the y e a r w h i c h i s c o n s i s t e n t  with  lb  ~i  1—'  1  40  9 0  SO  1  1  r^*'—i-  1—I—\  TO a o 9 0 1 0 0 110 L E N G T H O F M A L E S IN M M S .  F i g . l a . Length frequency  r 110  ISO  pc.URwe.So  r  1  l«0  1 ISO  r~  WD  for male anc-  hovy taken i n successive months of the year to i l l u s t r a t e the progression of age-group modes. Dotted l i n e s are f o r samples i n which the sexes are combined.  For further explanation see text.  ' 1  1 1 1 |  1  JAN.  |  1 1 |  !  1  1  | 1««7  \ 1 1 1  FEB.  r  \  \  ' !  1  ' !!47  MAR.  i i  i  ^VJIW i  I  1 ^ 1 \ v  APRIL  \ \  / ^y^  /  \ V ^11*7  /\  MAY  y  /  JUNE  /  \ \ . \ \ / \ ^y~~ /\ \ y \ y  \  1 •*  1  \  j  1  1  1  1  l  \  V  1  I 1 \  1 1 y^s\^- 1 / i X . \ \ 1 1 v, \  \ ^~-~y~~**\  JULY  1  ^y  \ \  AUG.  //\  \ \  I L I  \  \  \  SEPT.  /  1 \  i  OCT.  ' 1  |  |  DEC.  1  1 .•  1  '  1  1  1  1  SO  1  60  1 TO  eo  LENGTH OF  i  i  i  so  ioo  no  1  120  1 iso  |  1  J  l  40  l 1  |  1  1  1  j  |  1  | ] l |  1  i  I  l 1  vn  J  ] '  1  1 |  I  NOV. •  1  ' i  |  1 1|  1  1I \ \ l  \  '  I  | 1  | 1 iso  I  i ICO  FEMALES IN M M S .  F i g . l b . Length frequency  r cur-yes? f o r female anc-  hovy taken i n successive months of the year t o i l lustrate the progression of age-group;modes. further explanation see text.  For  the  expected s e a s o n a l growth;  and w i n t e r months and f a s t months. (fig.  This  pattern  i . e . slow growth d u r i n g  growth d u r i n g  the s p r i n g  i s shown p a r t i c u l a r l y w e l l  1) where samples  are included  to August  entirely  o f one age g r o u p and t h e r e f o r e p r o v i d e d  November do n o t p r o g r e s s ence  this  June t h e r e  year f i s h  fish  consisted  almost  a u s e f u l guide The modes o f  i n September,  t h e y were spawned.  O c t o b e r and  A l t h o u g h no  samples  g r o u p were t a k e n b e t w e e n the months o f November  seems l i t t l e  millimetres  f o r 19^7  r e g u l a r l y probably because o f a d i f f e r -  i n the time a t which  representing  90  samples  c o n s t r u c t i n g growth c u r v e s f o r o t h e r groups.  samples r e p r e s e n t i n g f i r s t  and  The 19^7  and summer  b u t one month f r o m  February  in  Inclusive.  for all  the f a l l  doubt t h a t  f i s h at lengths  a r e y o u n g e r t h a n one y e a r .  less  than  Growth d u r i n g t h e  s e c o n d w i n t e r a n d summer I s t r a c e d w i t h c o n f i d e n c e b e c a u s e o f the  19^-7  samples which a l l  Growth d u r i n g  the f o l l o w i n g  showed t h e same d o m i n a n t  y e a r can a l s o be t r a c e d w i t h  e n c e by r e a s o n o f t h e d o m i n a n t Plotting shown  in figures  The  i n June and J u l y  i n Table  July,  birth  III.  growth  lines  confid-  samples.  f o r the e n t i r e  life  f o r e a c h month/ span  (fig.  2).  growth  The b e g i n n i n g a n d end o f e a c h y e a r i s t a k e n  t h e month a t w h i c h maximum s p a w n i n g o c c u r s .  i s taken as 3 m i l l i m e t r e s ,  recorded larvae  group.  the p o s i t i o n s a t which the growth c u r v e s  same d a t a a r e u s e d t o show g r o w t h a s i n s t a n t a n e o u s  rates as  modes  l a and l b c u t t h e b a s e  shows t h e r e s u l t a n t  length  (Bolin,  I936).  the s i z e  Length a t  of the s m a l l e s t  F i g . 2.  Growth curves for male and female .anchovy based on the progression of age-group modes to show the seasonal and annual growth pattern*  -CI-  TABLE I I I Instantaneous Growth Rates f o r E n g r a u l l s mordax to s a t i s f y the equation L L^e^ where L T l e n g t h a t beginning of year, L£ = l e n g t h at end of year and k instantaneous, growth r a t e d u r i n g the annual time i n t e r v a l " t " . -  =  =  =  YEAR  MALE Length mm., ..  1st 3.0 2nd . 109.0 3rd 126.0 4th 138.0 5 th 147.5 6 th 2nd to 6th  -  108.0 126.0 138.0  -  155.0  - 15.7.5  k  FEMALE'  Length  3.1+71 0.11+9 0.088 0.065 0.0ij.8  0.087  3.0 109.5 128.0 141.0 151.0 159.0  mm.  - 109.5 - 128.0 - llj.1.0 151.0 - 159.0 - 166.5  A refinement i n the treatment of data was  k  3.1+% 0.151 0.094 O.066 0.050 0.045 0.090  used to t e s t  the v a l i d i t y of the h y p o t h e t i c a l growth p a t t e r n as d e s c r i b e d above.  Samples f o r the y e a r s 191+7  and. 1948  were combined by  months and years and the component modes f o r each combined sample  r e s o l v e d by the use o f p r o b a b i l i t y paper  (Harding, 1 9 4 9 ) .  T h i s method p r o v i d e s a means f o r s e p a r a t i n g the components of multimodal  l e n g t h frequency d i s t r i b u t i o n s .  Furthermore, i t  p r o v i d e s an estimate of the mean, the d i s p e r s i o n about the mean in  terms of standard d e v i a t i o n and the percentage  i n each component of the t o t a l frequency Twenty-one samples from 19^7  of i n d i v i d u a l s  distribution.  catches are combined by  month and sex to show the growth i n l e n g t h of age groups from February to September.  The r e s u l t s are presented i n t a b l e  The a n a l y s i s shows the 191+7  catches to be composed almost  t i r e l y of f i s h i n t h e i r second year.  A small percentage  t h i r d y e a r f i s h and only o c c a s i o n a l f i r s t , f o u r t h , and year f i s h were p r e s e n t .  IV. en-  of  fifth  TABLE  IV  A n a l y s i s of Length Frequencies of 21 Samples of Anchovy'from 1947 Catches by the use o f P r o b a b i l i t y Paper. Month  Feb  Sex  2nd Year  No. of Fish  Mean  S.D.  %  Mean  231 290  116.1 .119.4  4.7 4.4  98.0  131.8  %.  &  188 251  120.1 121.0  4.3 4.2  94.0 137.0 89.O 137.5  1.2  5>0 3.3 i r . 0  145.0  212 280  120.9 122.5  4.3 4.2  85.O 134.5 94.0 140.$  3.5 11.0 "2.8 6.0  144.0  3.4  3.0  150.0  1.0  552 % ' 297  125.6  3^7  128.5  4.0  159.0  1.0  &  4 t h Year  3rd Year S.D.  i  Mean  S.D.  5th Year  %  Mean  S.D.  i  1.0 1.0  99.0 138.0  March April May  ? ef  9 June  cf  July  cf  9 August  c?  9  125.9  72 65  131.2  100 130  132.6  128.4  99.0 136.3 4.0 100.0  2.4  1.0  1.0  3.9  76.0 I39.7 77.0 142.5  3-9 23 i'O 1.6 10.0  149.0 148.3  1.0 1.2 12.0  5.9 5.8  9 6 . 0 140.0 98.0 140.7  3.0 3.8 11.0  146.0 149.0  1.0 1.0  -11To t e s t the r e l i a b i l i t y  o f the seasonal h y p o t h e t i c a l  growth curves shown i n f i g u r e 2 the means f o r second year i n 19V7  fish  samp]B s are compared w i t h the p o i n t s at which the hy-  p o t h e t i c a l curve c u t s the base l i n e s each month.  The  compari-  son i n t a b l e V suggests the v a l i d i t y o f the o r i g i n a l e s t i m a t e . TABLE V. Comparison of Modes ( f i g . 2) and Means ( t a b l e I V ) f o r Second Year Anchovy by Months. Month  Sex  Mode in mms.  116.0 118.0  February  Mean In mms.  116.1 119.4  117.0 119.0  March %  c?  118.5 120.0  120.1 121.1  May  120.0 123.0  120.9 122.5  June ?  123.5 125.5  125.6 125.9  i  126.0 128.0  128.5 128. k  ?-  128.0 130.0 .  128.k 132.6  April  -  !  %  July August  To t e s t the r e l i a b i l i t y  of the annual Increments  sug-  gested by the o r i g i n a l growth curves, e i g h t samples from catches made i n June 19k 7 and 19k 8 were combined by year and sex, and the components of the frequency d i s t r i b u t i o n s by the use o f p r o b a b i l i t y paper. year c l a s s e s 1,  3,  5,  mostly 2nd year f i s h .  and 6 .  Samples from 19k8  resolved  represented  Samples from 19k 7 represented  The means f o r each year are entered i n  t a b l e V I and compared w i t h the modes taken from f i g u r e 2 f o r June.  -12TABLE V I . Comparison o f Modes ( f i g . 2), and Means (Harding's P r o b a b i l i t y Method) o f 1st, 2nd and 3rd Year Anehovy f o r June. Age c l a s s  Sex  Mode i n turns.  _  &  I II  %  III «_  • _ . .  %  1  The comparison  i  Mean i n mms.  105.0 106.0  101+.7 107.7  123.5 125.5  125.6 125.6  136.5 138.5  ,  135.0 140.5  i n t a b l e VI suggests the v a l i d i t y of  the o r i g i n a l estimate o f annual growth increments.  The estimated  growth increment d u r i n g the 2nd year may be s l i g h t l y low. r a t e s f o r the 4th, 5th, thetical.  and 6th year must s t i l l  Growth  remain hypo-  The June 194$ samples i n c l u d e d one female 158 m i l -  l i m e t r e s i n l e n g t h and one female l68 m i l l i m e t r e s i n l e n g t h . S c a l e r e a d i n g s from these two f i s h i n d i c a t e that they are 5 and 7 y e a r s o f age r e s p e c t i v e l y . Scales During 191+7  two o r more s c a l e s were taken from  each  of more than 500 f i s h and mounted dry between two microscope slides.'  T h i s method o f p r e s e r v a t i o n was found to be s a t i s -  f a c t o r y as d e t a i l s i n the markings showed as c l e a r l y three years i n t h i s mount as they d i d when f r e s h .  after  S c a l e s were  removed from a p o s i t i o n immediately i n f r o n t o f and d o r s a l t o the a n a l f i n wherever p o s s i b l e .  F r e q u e n t l y i t was found  that  o n l y a v e r y few s c a l e s were l e f t on the f i s h and i t was necessary, to take s c a l e s from o t h e r p a r t s where the annual markings  -13showed l e s s c l e a r l y . The described  s c a l e s o f E n g r a u l l s mordax are s i m i l a r to those f o r the A u s t r a l i a n anchovy E n g r a u l l s a u s t r a l i s  (Blackburn, 1 9 5 0 ) .  The imbedded p a r t o f the s c a l e bears  w i d e l y spaced s t r i a e running p a r a l l e l to the a n t e r i o r and shoulder margins and o b l i q u e l y towards the side margins.  The  p o s t e r i o r p a r t o f the s c a l e bears f i n e , c l o s e l y approximated s t r i a e which appear almost opaque near the b a s a l l i n e .  In  l a r g e f i s h the s t r i a e are c l o s e l y approximated i n bands spaced at d e c r e a s i n g  i n t e r v a l s from the b a s a l l i n e to the a p i c a l o r  shoulder margins. occurs r e g i o n s . o f  Accompanying these bands there  frequently  i n t e r r u p t e d and branched s t r i a e , or r e l a t i -  v e l y wide^instriated areas, appearing as t r a n s l u c e n t The  arcs.  u n s t r i a t e d areas are o c c a s i o n a l l y bordered on t h e i r o u t e r  margins by s t r i a e running i n a d i f f e r e n t d i r e c t i o n to the widely spaced s t r i a e i n s i d e the band.  These v a r i o u s i r r e g u l a -  r i t i e s were found s i n g l y o r i n combinations i n the m a j o r i t y of s c a l e s , and showed most c l e a r l y i n the a p i c a l o r shoulder parts.  In only a few cases was i t . p o s s i b l e t o t r a c e the bands  completely around the imbedded p a r t o f the s c a l e . The  areas o f c l o s e l y approximated s t r i a e accompanied  u s u a l l y by t r a n s l u c e n t majority  arcs are taken to be annual r i n g s .  o f s c a l e s from February, March, and A p r i l  showed the r i n g s at the margin. down during  samples  The r i n g s are t h e r e f o r e  the slow-growing w i n t e r months.  The  laid  Small f i s h , un-  doubtedly I n t h e i r f i r s t year, from June and J u l y samples, showed a wide and r a t h e r i n d i s t i n c t r i n g at some d i s t a n c e the  s c a l e margin.  from  ~ l k =  Many d i f f i c u l t i e s were encountered i n i d e n t i f y i n g the w i n t e r r i n g s and v e r y few r e a d i n g s were accepted w i t h confidence,. In no one r i n g was i t p o s s i b l e to f i n d s t r i a e f o l l o w i n g completely around scale.  the c l o s e l y  approximated  the embedded p a r t o f the  T r a n s l u c e n t areas caused by i r r e g u l a r , broken or w i d e l y  spaced s t r i a e were f r e q u e n t l y found between bands o f c l o s e l y approximated  s t r i a e as w e l l as accompanying them.  In the f i n a l  a n a l y s i s the i d e n t i f i c a t i o n of a r i n g was taken to be a band which appeared d i f f e r e n t from the remaining p a r t s o f the s c a l e by reason of one or more o f the above-mentioned  irregularities.  Readings were made from 551+ s c a l e samples without r e f e r e n c e to l e n g t h .  The same set o f s c a l e s was read a second time with=  out r e f e r e n c e to l e n g t h or to the f i r s t  readings.  Only age de=  t e r m i n a t i o n s which corresponded i n both readings were accepted. Of the 551+ s c a l e s , 353 or approximately 6k$ showed agreement i n both r e a d i n g s .  Mean l e n g t h s by month and sex were c a l c u l a t e d are  f o r each age g r o u p s t h e r e s u l t s .presented i n t a b l e V I I . TABLE VIIo Mean Lengths o f Anchovy C a l c u l a t e d from S c a l e Readings of 353 P i s h by Sex, Month and Age.  Month  Sex 1  0  No. , Mean  8 15 30  Feb April ?  May June August  cf 9  . of 16  1 0 0 . 0  . %  1 0 2 . 9  . <* 9  No.  1 9  I Mean  Age Group II III .No.l Mean No. < ' Mean  117.8  3  1 1 7 . 0  1 2 0 . 1  2  121.5  7  2 9  120.k 123.2  11  29  1 2 2 . 3  1 2  32 25 16 11+  ll  123.3  125.9 128.1 125.9 1 2 9 o 9  8 21 9  126 o i | . 131.5  3  ft  IV No. Mean 1  132.8  132.5 1 2 9 . 0  1  135.5  139.0  7  114-1.7  2  11+5.3  3:  llj.0.0 15  5  13k * 0  1+  1 2 9 . 9  I k 2 o 0 ;  150.0  -15The  r e s u l t s of s c a l e readings are c o n s i s t e n t w i t h age  determinations to  using length frequencies.  the o r i g i n a l growth estimates  suggested  The m o d i f i c a t i o n s by c a l c u l a t i n g the  means o f age groups u s i n g p r o b a b i l i t y paper (table VI) are supp o r t e d by r e s u l t s o f s c a l e r e a d i n g s ; i . e . that growth d u r i n g the summer months o f the second year 19).  The s c a l e readings  should be g r e a t e r (page  show t h a t average l e n g t h s f o r 5th  and 6th year f i s h are s l i g h t l y l e s s than are shown i n t a b l e I I I . The  l a r g e s t f i s h found i n the commercial c a t c h samples  was a female l68 m i l l i m e t r e s i n l e n g t h and, a c c o r d i n g t o s c a l e r e a d i n g s , i n i t ' s s i x t h year.  Only 21 females were found a t  l e n g t h s g r e a t e r than 150 m i l l i m e t r e s .  S c a l e readings  two o f these f i s h to be i n t h e i r 5th y e a r .  show  The l a r g e s t male  was 153 m i l l i m e t r e s i n l e n g t h and i n i t ' s 5th year.  Only a  •small percentage o f f i s h taken i n the commercial catches are o l d e r than f o u r y e a r s . Sex  Ratio Changes i n the sex r a t i o throughout the s p r i n g and sum-  mer months are shown i n t a b l e V I I I . sample taken from February to 55 females.  The sex r a t i o o f each  to May i s approximately  1+5 males  I n May the average p r o p o r t i o n o f males i n c r e a s e s  and approaches an average r a t i o near p a r i t y i n June and J u l y . In June o n l y ij. of the 10 samples showed a predominance o f f e males, and i n J u l y o n l y one o f the ij. samples contained more females than males.  Males, t h e r e f o r e , predominate i n the ma-  j o r i t y o f schools i n J u l y as the spawning season approaches. The  average sex r a t i o f o r the three J u l y samples, i n which  -16the males predominated,  i s 55 to 1+5.  In August  samples  c o n t a i n i n g females n e a r i n g the completion of spawning,  the  sex r a t i o r e v e r t s to about 2+0 to 60 w i t h the females again predominating. The change i n sex r a t i o at the approach of the spawning, season does not r e s u l t from males maturing e a r l i e r than the females and e n t e r i n g the schools i n t h e i r f i r s t y e a r . T h i s i s shown by the o b s e r v a t i o n t h a t samples c o n t a i n i n g or no 1 s t  few  y e a r f i s h c o n s i s t e n t l y show the change to a predomi-  nance of males as the spawning  season approaches.  TABLE V I I I . Sex R a t i o of Anchovy by Months; a l l l o c a l i t i e s combined. Month  No. o f Samples  No. of Fish  Males  Females  %  Feb  5  603  144.8  55.2  March  2  226  1+2.6  57.1+  April  7  811  1+3.0  57.0  May  3  365  1+6.8  53.2  10  1301|  1+9.1  50.9  June July  1+  62+2+  50.2  1+8.8  August  2  224.7  1+0.8  59.2  Weight-Length  Relationship  During the course of sampling, weights were measured to the n e a r e s t gram f o r over 2500 f i s h r e p r e s e n t i n g 20  samples.  By the method of l e a s t squares the data were analysed to show d i f f e r e n c e s i n body form of males and females throughout  -17th e s p r i n g and summer months. which might  To a v o i d the  difficulties  a r i s e due to changes i n growth c o n d i t i o n s i n  d i f f e r e n t years o n l y data from one y e a r ' s sampling were used i n the a n a l y s i s . R e s u l t s of the a n a l y s i s of the length-weight data are presented i n t a b l e IX.  The r e l a t i o n s h i p f o l l o w s the u s u a l ex-  3 p o n e n t i a l form, c l o s e l y approximating W  aL .  =  A difference  between the slopes of the r e g r e s s i o n l i n e s f o r males and f e males I s c o n s i s t e n t l y shown i n each time p e r i o d .  In each  case the v a l u e s f o r "b" and f o r "a" are g r e a t e r f o r females than f o r males showing that females Increase more r a p i d l y i n weight w i t h i n c r e a s e d l e n g t h s , and that i n each corresponding time p e r i o d the females are h e a v i e r than are the males at any given length. TABLE IX. Length/V/eight R e l a t i o n s h i p of Anchovy d u r i n g the S p r i n g and Summer Months of 19k7 to P i t the Equation W aL , where "b" i s the Regression Coeff i c i e n t and " a " . i s the Y - I n t e r c e p t . :  Month  Sex  Feb - March  Length Interval . i n mm.  <?  102 - 13k W - . 0 0 0 0 0 1 5 7 L ^ ' ™ . 0 0 0 0 0 2 0 ^ °105 - 137 W 3  % April -  =  May  June - J u l y  Lth/Wt. R e l a t i o n s h i p  c? .  110 - 150 w - .00000090L^2/ ^ 109 - ll|.8 W z .OOOOO376L^ ,, 3•201 113 - li+9 W .00000k62L^ 117 - 159 W . 0000049^ • 120 - l k l w - . 0 0 0 0 3 5 3 ^ * ^ 120 - l k 9 w .0002103L 1 Q n  =  1 V U  August  o  r  •L-  v  -18-  An abrupt change in the relationship i s shown between the June-July combined data and the August data both for males and for females. with spawning.  This change i s no doubt associated  The change in length-weight relationships  during the months from February to July i s associated with the maturation of gonads.  The twenty 19k7 samples used in the  analysis each consisted of 80% to 100$ 2 n d year fish and few or no immature 1st year fish.  The changes in the males, cor-  responding closely to the changes in the females during the spring and summer months, strongly suggest that the males also become mature in their second year. The increase in weight i s slightly greater than the length cubed for pre-spawning adult males and females, and slightly less than the length cubed for the spawning adults. Adult males and females experience a maximum weight in the late spring and early summer prior to spawning.  The weight  of the larger females seems to be more affected by the maturing of the gonads than for smaller individuals.  This may  reflect the maturation of more eggs in the larger adults. IV. MATURITY STUDIES Methods Ova diameter measurements from adult ovaries were used to study the maturity of anchovy from the coast of British Columbia.  The method was introduced by Dr.  W.F. Thompson  in his study of the Pacific halibut (Thompson, 1915)  and was  later used by Frances N. Clark in studying the maturity of  -19-  the California sardine (Clark, 1931). The study was based on ten ovaries randomly selected from each commercial catch during 1947 and 194°'.> and representing f i s h taken from February to September.  Each ovary, was  preserved in 10% formalin for subsequent examination. The time consuming process of measuring eggs permitted only lOlj. of the ovaries to be examined in detail, but this number was found to be sufficient to show the growth to maturity. After the ova samples had hardened in formalin, a fraction of each ovary was teased out on a slide and the diameters measured by means of a micrometer eye-piece i n a compound microscope at a magnification which gave a value of 0.10 mm. to each of the hundred squares of the grid.  Por  maturing ovaries, 200 eggs larger than 0.15 mm. were measured to the nearest 0.05 mm. at a magnification of 2 0 X .  For im-  mature ovaries, containing only eggs less than 0.15 mm.,  100  eggs were measured to the nearest 0 . 0 2 mm. at a magnification of l+OX. At the approach of spawning one, two, or three groups of maturing eggs appeared i n the ovaries.  To assure repre-  sentation of each of these groups In their correct numerical proportions and sizes i t was necessary to measure 200 eggs. An immature group of eggs persisted even in the mature ovaries. These eggs were not measured in maturing cvaries. Maturing and mature anchovy eggs are peculiar in being ellipsoidal i n shape.  The ratio of length along the major  axis to width across the minor axis was found consistently to  -20-  approximate 7 to 1+ in maturing eggs of a l l sizes. the lengths along the major axes were measured.  Only Throughout  the study these lengths are called "diameters" for want of a better term. Preservation of ovaries in 10% formalin permitted the eggs to harden without apparent distortion or shrinkage. In teasing out a section of each ovary for measurements a thin layer of'formalin was run onto the slide to prevent distortion of the eggs by drying.  Because of the ellipsoidal  shape i t was found necessary to exercise care in this process. Too much formalin caused the eggs to be deflected from their horizontal position on the slide and resulted in inaccurate measurements. 'A corresponding range of egg sizes was found In samples taken from the anterior, central and posterior parts of several ovaries. Results of the maturity study based on ova measurements are subject to the following limitations.  Only females  are used because of d i f f i c u l t i e s found in determination of the' maturity condition in the males by gross examination.  The  number of ovaries examined in detail was limited by the time required for one worker to measure 200 eggs.  Sound compari-  sons of maturity conditions of fish from different localities were not possible because of the lack of sufficient samples in any one month. No samples were available for the months of September to January and very few fish were found in ripe or spent condition.  -21G-rowth o f t h e i l R l p e n i n g  Ova  The measurement d a t a r e v e a l  a progressive  egg d i a m e t e r s t h r o u g h o u t t h e s p r i n g and accompanied groups.  b y a s e g r e g a t i o n o f egg  sizes into  spring  the development  show a m u l t i p l i c i t y  three or four  bitrarily  classified  females  o f modes.  o f t h e s e modes and t o f o l l o w  o f t h e m a t u r i n g o v a t h e d a t a were g r o u p e d  in  summer months  Frequency polygons o f ova d i a m e t e r s from  taken i n the l a t e trace  early  increase i n  according  To  the growth  i n nine stages ar-  t o the p o s i t i o n o f t h e l a s t mode  t h e o v a d i a m e t e r f r e q u e n c y * curves'•'•  The  s t a g e s a r e as  follows: Stage Stage Stage Stage Stage Stage Stage Stage Stage  I II III IV V VI VII VIII IX,.  Last Last Last Last Last Last Last Last Last  mode mode mode mode mode mode mode mode mode  With Increase i n size in  the g e n e r a l appearance  at l e s s than 0 , 2 0 mm. f r o m 0 . 2 0 t o 0.29 mm. from 0 . 3 0 to 0 . 3 9 mm. f r o m O.ij.0 t o 0.IL9 mm. from 0 . 5 0 to 0 . 5 9 mm. f r o m O.oO t o 0.69 mm. from 0 . 7 0 to 0 . 7 9 mm. from 0 . 8 0 to 0 . 8 9 mm. a t 0 . 9 0 mm. o r g r e a t e r .  t h e r e i s a c o r r e s p o n d i n g change  o f the m a t u r i n g ova.  The  o v a com-  prising  t h e immature g r o u p  contain  a l a r g e c e n t r a l n u c l e u s s u r r o u n d e d by amorphous  toplasm.  a r e r o u g h l y s p h e r i c a l i n shape  and  deu-  A t t h e o n s e t o f m a t u r i t y some o f t h e ova f r o m t h e  immature g r o u p become e l l i p s o i d a l minishes i n size,  i n shape,  the n u c l e u s d i -  t h e d e u t o p l a s m becomes g r a n u l a r and t h e  t a k e on a t r a n s l u c e n t  appearance.  A t 0 . 3 5 mm.  t o O.kO  mm.  ova the  o v a become opaque and t h e n u c l e u s d i m i n i s h e s f u r t h e r i n s i z e . A t 0 . 6 5 mm.  to 0.75  ova are q u i t e parent,  mm.  opaque.  t h e n u c l e u s i s no Beyond 0 . 7 5  mm.  longer  evidentatfthe  t h e ova become  t h e t r a n s i t i o n b e g i n n i n g a t one p o l e o f t h e  trans-  ellipsoidal  F i g . J.  Ova diameter frequency rcurv-aa. showing  growth of anchovy eggs to maturity. explanation see text.  For further  -22-  eggs.  At diameters of 1.00  the appearance  to 1.30  mm.  of newly spawned eggs.  and almost completely t r a n s p a r e n t .  mm.  the ova approach  Ripe ova are c o l o u r l e s s  The egg membrane i s t h i n  and d e l i c a t e showing no s c u l p t u r i n g or markings.  No o i l glo-  b u l e s are p r e s e n t and the y o l k i s composed of separate masses g i v i n g the appearance of b e i n g made up of l a r g e c e l l s . > • S i z e v a r i e s from 1.23 0.65  mm.  mm.  to 0 . 8 2 mm.  to 1.55  mm.  along the major a x i s and from  along the minor a x i s ( B o l i n ,  1936).  Measurements from 78 a d u l t females from 191+7 catches were grouped a c c o r d i n g to the p o s i t i o n of the l a r g e s t mode i n t h e i r respective maturity stages.  The r e s u l t i n g diameter f r e -  quencies are weighted to 100 and p l o t t e d i n f i g u r e 3 to show the h i s t o r y o f the r i p e n i n g ova. was  An immature group of eggs  found i n each ovary, but o n l y i n stage 1 were the eggs  a c t u a l l y measured. of eggs may  The development  of these maturing groups  be t r a c e d through the s u c c e s s i v e stages.  In  stage '.'21 a group of eggs has s t a r t e d the growth to m a t u r i t y . In stage 3 a second group of maturing eggs I s b e g i n n i n g to take form. 0.1+0 mm.  The f l a t n e s s o f the curve at about 0.20 mm.  and  i n stage 1+ suggests that growth of the ova i s con-  tinuous throughout the range of s i z e s and i n v o l v e s a growth w i t h i n the i n t e r m e d i a t e group as w e l l as growth from the immature stage.  In stage 6 a t h i r d group of maturing eggs i s  b e g i n n i n g to form.  Stages 7,  8,  and 9 c o n s i s t of egg diameters  of three d i s t i n c t groups i n a d d i t i o n to the immature groups. In stage 9 the l a r g e s t maturing eggs are b e g i n n i n g to separate o f f from the i n t e r m e d i a t e groups.  The ova comprising t h i s  -23group are t a k i n g on the appearance o f newly spawned eggs and are t h e r e f o r e almost The  ripe.  s e r i e s o f frequency polygons i n f i g u r e 3 i l l u s -  t r a t e s the p r o g r e s s i v e growth o f the ova to m a t u r i t y without r e f e r e n c e to time.  The number o f f i s h comprising each  polygon  i s entered on the graph by months to show that t h i s growth of the ova f o l l o w s a c h r o n o l o g i c a l o r d e r .  Females taken i n any  one month from s p r i n g to e a r l y summer may c a r r y ova representing  several d i f f e r e n t  stages.  The f i s h caught  example, r e p r e s e n t e d stages 2 to 9 .  i n June, f o r  One of the reasons f o r  t h i s d i f f e r e n c e i n m a t u r i t y at any g i v e n time d u r i n g the spawn i n g season seems t o i n v o l v e l o c a l i t y of capture and i s probably r e l a t e d to the temperature of growth t o m a t u r i t y .  c o n d i t i o n s d u r i n g the p e r i o d  The o v e r a l l p i c t u r e shows a p r o g r e s s i o n  of m a t u r i t y stages w i t h time throughout  the summer months.  To i l l u s t r a t e t h i s more c l e a r l y the data were combined by months as percentage k).  o f females i n each m a t u r i t y stage ( f i g .  In February, 100 p e r cent of the o v a r i e s from eleven sam-  p l e d f i s h c o n t a i n e d ova i n stage 1. were i n stage 1,  In A p r i l o n l y 26 p e r cent  and 6k p e r cent In stage 2 .  females c a r r i e d eggs l a r g e r than stage 1.  By May a l l a d u l t  In J u l y the m a j o r i t y  o f adult females were i n stage 8 and approaching  the onset o f  spawning. Frequency  o f Spawning and Number of Eggs Spawned  The m u l t i p l i c i t y o f modes i n ova diameter curves f o r maturing  females  frequency  suggests that more than one b a t c h  of eggs are spawned each season.  The p o s s i b i l i t y that the  t o o -  FEB.  s e  il2  100  so  \  MARCH  8$  APRB.  II*  \ EM  100> -  s o  \  i o a MAY  i- so-  s o  1 0  29 . r a -  s o -  F^f  s  I  JULY  7?  AUG. I+<?  \ 2  33$  1^ F33  8  t s .  SB-  JUNE  89  3  +  5  MATURITY  J3.  6  7  e  9  STACKS  Fig. 4. Percentage of adult female anchovy i n each stage of maturity.  Data grouped by months.  -2k-  maturing eggs other than those i n the largest size group may be carried over to the succeeding spawning season i s very unlikely in view of the observation that only immature females with eggs in stage 1 were taken in February samples. That these intermediate maturing groups are resorbed or that they degenerate following the spawning of a single batch of eggs i s also very unlikely. Adult females taken in late August were found to contain occasional degenerating mature eggs at the same time that smaller size groups were growing to maturity. These smaller groups of eggs which remain i n the ovaries after the largest group had been spawned out show no signs of resorption or degeneration. A distinct break in the continuity of the progression of maturity stages throughout the spring and early summer months was found in the appearance of the ovaries of females taken during the last week in August.  Ova'measurements from l6 fe-  males in this sample included stages from 1 to 8 (fig. 5)« As mentioned in the preceding paragraph occasional degenerating ripe eggs were found in most of these fish to suggest that spawning had commenced. Each ovary had a flaccid appearance unlike any encountered previous to this month. The high percentage of stage 1, 2, and 3 females further suggests that spawning was nearing itfs completion. A similar situation was encountered in ovaries from two samples taken July k and July 15, 1948'  Here again the ovaries had a flaccid appearance  and contained some large degenerating eggs.  .10  -10  .50  .40 OVA  .SO  .60  DIAMETERS  -TO IN  »0  .*0  I0O  IIO  1.10  ISO  1.40 j  MMS  I  Fig.  5.  Ova diameter frequency polygons ftbr 14  female anchovy taken i n J u l y , 1948; showing the grouping of ova s i z e s d u r i n g the e a r l y season.  to  t  f  spawning  T25The e x i s t i n g evidence shows that three groups of eggs are growing towards-maturity d u r i n g the summer months. I f only the l a r g e s t group of eggs i s spawned out, the r e maining two groups would be expected t o m a i n t a i n a constant n u m e r i c a l r a t i o a f t e r the spawning.  I f , however, succeeding  groups of eggs continue to grow to m a t u r i t y and are i n time spawned oxit, the n u m e r i c a l r a t i o of eggs i n the l a r g e s t maturing group to eggs i n these succeeding groups would be expected to i n c r e a s e w i t h each spawning.  Furthermore, i f  each o f the maturing groups i s spawned out, the numbers o f groups would be expected t o decrease as the spawning advanced.  season  A comparison was made of the n u m e r i c a l r a t i o s  of ova i n each maturing group f o r 19 f i s h taken i n June and J u l y , 191+7, w i t h f i s h taken from the J u l y , 191+8 samples. the  By  use of p r o b a b i l i t y paper, (Harding, 191+9), the average  n u m e r i c a l r a t i o s of ova i n each maturing group were estimated 26 i n d i v i d u a l females i n stage 5 ,  for  7, 8,  and 9»  Only  these stages were used i n the comparison because they are the only l a t e stages showing w e l l d e f i n e d modes.  The r a t i o values  are p r e s e n t e d i n t a b l e X. TABLE X. R a t i o s of Numbers of Eggs i n each Maturing Group by-Stages i n 191+7 and 1914.8 Samples. Maturity Stage  June-July. 191+7 No. of females Ratio  5 7  6  " 9  2  , 8  6  55:1+5 31+: 39:27 30:1+1:29 37:39:21+  J u l y , 191+8 No. of females R a t i o 6 3  1 1  1+6:51+ 1+9:51 I4.8:52  31+: 1+8:18  - 2 6 -  Differehces in the numerical ratio between the largest maturing groups of eggs and the intermediate groups in each of the two' sets of samples are apparent in table X.  In the  19!L7 -females, which contained maturing eggs prior to spawning, the numerical ratios of eggs in the largest group to eggs in the intermediate groups were in each stage greater than the corresponding ratios for the 191+8 f i s h whieh had commenced to spawn. The one individual in stage 9 i s the exception to this observation. Because no degenerating eggs were found in the ovaries of this female, and in view of the ratio of I4..56 to  1.00,  i t i s taken that spawning has not yet begun.  The difference in the condition of the ovaries before spawning and after spawning has commenced becomes more apparent when ova diameter frequencies of corresponding maturity stages are compared.  Figure 5 presents ova diameters for representatives  of stages 5 to 9 taken from July, 191+8 samples.  The most  striking difference from the frequency curves presented in figure 3 i s the absence of a well defined mode immediately preceding the largest maturing group of ova in stages 7 and 9. This feature was to be expected in females, which had commenced to spawn, and suggests that intermediate maturing groups of eggs undergo a less rapid growth as successive batches of eggs are spawned out. The ova.diameter frequency polygon representing the one f i s h in stage 9 suggests that our arbitrary classification cf maturity stages should be extended to include a stage 10 in which the largest maturing batch of eggs has become separated  -27-  in size from the preceding groups. curve at 0 . 2 0 mm.  The flattening of the  and'0.70.mm. suggests the development of  a fourth group of maturing eggs as the largest group i s about to be spawned.  The ratio of lt.56 to 1 given in table I I  would lend further support to this suggestion. The 1 5 females examined from two samples taken during the  last few days in August, 1 9 4 7 represent an advanced  stage in the spawning season (fig. 2i).  Degenerating ova were  found in a l l but three of the ovaries, and each ovary had a flaccid appearance showing that the fish were either completely or partly spent.  The eight f i s h with ova in stages  2 and 3 may possibly resorb the few remaining eggs larger than 0 . 2 0 mm.  Because no isolated maturing group of eggs beyond  stage 3 was found in any ovary i t i s suggested that resorption of this group would eventually occur.  The largest of these  groups w i l l probably be spawned out.  A difference i s noted  in the numerical ratios i n the two maturing groups of ova from the July, 191+8 samples as shown in table X.  The ratios  of eggs in the largest maturing group to eggs in the intermediate group were 6 2 to 3 8 , 5 6 to kix, and 5 4 to i i 6 in stages 5 , 6 , and 7 respectively.  The greater numbers in the inter-  mediate group show a retarding or cessation i n growth of the eggs beyond 0 . 3 0 to 0 . 4 0 mm.  in the latter part of the spaw-  ning season. That more than one batch of eggs i s spawned each season i s f i r s t suggested by the multiplicity of modes in ova diameter frequency curves. The development and progression in size of individual groups of maturing eggs i s traced  -28throughout the summer months u n t i l June and J u l y when three or f o u r groups are p r e s e n t i n the o v a r i e s .  Spawning i s eviden-  ced by the o c c a s i o n a l presence i n the o v a r i e s o f a few r i p e eggs accompanied  by one or more s m a l l e r maturing groups.  A  change i n the n u m e r i c a l r a t i o o f the l a r g e s t group o f mature eggs to the s m a l l e r maturing eggs, and a decrease i n the numbers o f maturing groups o f eggs i n f l a c c i d o v a r i e s c o n t a i n i n g degenerating r i p e ova l e n d f u r t h e r support to the evidence that female anchovy spawn more than once each y e a r . Evidence from the 26 females -which had commenced to spawn s t r o n g l y suggests that three batches of eggs are spawned each year..  Graphs o f frequency curves f o r ova diameters  of f i s h i n stage 9 show three d i s t i n c t maturing groups and a p o s s i b l e f o u r t h group d e v e l o p i n g • a t about 0.20 mm.  A group  -of small eggs was$ s"&eni'"-'> to p e r s i s t i n o v a r i e s of f i s h had commenced to spawn.  which  Because no i s o l a t e d groups of matu-  r i n g eggs were found a t l e n g t h s l a r g e r than 0.30 mm.  i t was  suggested t h a t t h i s group o f eggs w i l l not continue to grow to m a t u r i t y .  The s i t u a t i o n i n the o v a r i e s f o l l o w i n g the spaw-  n i n g o f one b a t c h -of eggs w i l l  show three maturing groups o f  eggs; the spawning o f two batches o f eggs w i l l l e a v e two maturing groups; the spawning o f three batches w i l l leave one group i n which growth has been r e t a r d e d or has ceased. T h i s l a t t e r s i t u a t i o n was apparent i n the m a j o r i t y o f females taken i n l a t e  August.  Estimates were made o f the number o f eggs produced i n one spawning and i n one y e a r .  The number o f maturing eggs  i n the o v a r i e s of s i x female anchovy i n l a t e stages of m a t u r i t y  -29-  were e s t i m a t e d as f o l l o w s .  A f t e r hardening each p a i r of  o v a r i e s i n 10% f o r m a l i n the excess m o i s t u r e was a p i e c e of absorbent paper. gms.) 0.20 was  of each was mm.  removed on  A s m a l l sample p o r t i o n  (0.01  taken, and counts of a l l eggs larger, than  made f o r the sample.  The  t o t a l weight o f the o v a r i e s  determined and the t o t a l number of maturing eggs estimated  by m u l t i p l y i n g the sample count by a f a c t o r e x p r e s s i n g the r a t i o between the weight of the sample and the t o t a l of the o v a r i e s .  weight  The r e s u l t s are p r e s e n t e d i n t a b l e X I .  counts are to be c o n s i d e r e d as minimum because eggs t o m a t u r i t y i s not complete  The  growth of the  i n any.one s e t of o v a r i e s .  TABLE X I . Number of Maturing Eggs i n the Gonads of A d u l t Female Anchovy During J u l y . Length i n  No.  mm.  Sample Date  of Maturing Eggs  -<  130 12+2  lIOi-,013  191+7.  124-8  156,158 . 114.2,1167 133,000  103 . 158  88,560 92,000  July, 191+8.  July,  j  j  The data p r e s e n t e d i n t a b l e XI i n c l u d e s o n l y o v a r i e s showing modes of maturing eggs between 0.70  mm.  and 0.9  mm.  The data are d i v i d e d i n t o two groups r e s p e c t i v e l y r e p r e s e n t i n g f i s h approaching the spawning season and f i s h which have commenced to spawn.  E s t i m a t e s of the t o t a l number of maturing  eggs f o r the former group  average  12+3*912.  Reasons have been  g i v e n f o r b e l i e v i n g t h a t these eggs, comprising three s i z e  been  groups,would haue^spawned i n three b a t c h e s .  The n u m e r i c a l  ratio  -30of the  eggs i n the l a r g e s t maturing group to maturing eggs i n s m a l l e r groups i s approximately 1 to 3 ,  t h e r e f o r e the num-  ber of eggs i n each spawning would be o n e - t h i r d of the t o t a l or  approximately 14.8,000. The two females with l e n g t h s of 103 m i l l i m e t r e s  and  158 m i l l i m e t r e s hade commenced to spawn as shown by the p r e sence of degenerating eggs i n t h e i r o v a r i e s .  The  average  number of maturing eggs f o r these two i n d i v i d u a l s i s 90,280 or  approximately t w o - t h i r d s of the average complement of  maturing eggs shown i n the f i r s t  group of data, i n d i c a t i n g  that one batch of eggs has a l r e a d y been spawned out.  That  more eggs are matured i n l a r g e r female anchovy i s n e i t h e r proved nor d i s p r o v e d by the s m a l l amount of data. Length at F i r s t M a t u r i t y The data from commercial  catches presents d i f f i c u l t i e s  i n the i n v e s t i g a t i o n of l e n g t h at f i r s t ' m a t u r i t y . immature f i s h were r e p r e s e n t e d i n the c a t c h e s . data from samples the to  Very  few  The l e n g t h  i n which immature f i s h were found d u r i n g  months of March to June i n c l u s i v e are combined i n t a b l e XII show the s i z e at f i r s t m a t u r i t y .  Mature females are d i s -  t i n g u i s h e d from the Immatures by gross examination of the gonads.  The immature o v a r i e s are s m a l l , t h r e a d l i k e , and  c o l o u r e d to white i n appearance.  Maturing o v a r i e s are l a r g e  and bloodshot i n the e a r l y m a t u r i t y stages. the  straw-  In l a t e r stages  o v a r i e s show the orange-red c o l o u r of the pigmented  eggs.  -31TABLE XIV. Number and Percentage of Maturing Female Anchovy by Length i n March, A p r i l , May and June. Length i n  Total  mm.  95-99 100-10k 105-109 110-114 115-119 120-121|  No.  No.  i  Mature  Percent Mature  1 2 71 139 132 132  11 14 74 143 134 132  9 96 98 99 100  The t a b l e shows a sharp Increase i n the p r o p o r t i o n of mature f i s h at l e n g t h s of 105 mm. during the summer months.  to 109 mm.  i n females taken  T h i s l e n g t h corresponds to the  p o i n t o f s e p a r a t i o n between l e n g t h f r e q u e n c i e s of f i r s t  and  second y e a r f i s h as shown i n a p r e v i o u s s e c t i o n , and suggests that female anchovy mature i n t h e i r second y e a r . at  A l l females  l e n g t h s l e s s than 95 m i l l i m e t r e s were immature and a l l  females g r e a t e r i n l e n g t h than 120 m i l l i m e t r e s were mature. Three females at l e n g t h s of 97 mm.  to 103 mm.,  " f i r s t y e a r f i s h , were mature i n August. the  representing  I t i s concluded that  m a j o r i t y of female anchovy mature i n t h e i r second year,  but the o c c a s i o n a l i n d i v i d u a l may  mature i n i t s f i r s t y e a r .  The data on ova diameter l e n g t h f r e q u e n c i e s suggests that f e males t h a t commence to mature i n the s p r i n g months w i l l t u a l l y spawn i n the same y e a r . mature eggs may The Spawning  even-  There i s no evidence t h a t  degenerate b e f o r e r e a c h i n g the r i p e  condition.  Season  The f o r e g o i n g d i s c u s s i o n of the development  of the ova  throughout the s p r i n g and summer months, shows a p e r i o d i c i t y  -32i n the spawning August.  season r e s t r i c t e d to the months of J u l y and  The y e a r 191+7 p r o v i d e d a good set of samples to r e -  p r e s e n t each month from February to September.  I t was  shown  that no n e a r l y r i p e females were p r e s e n t i n the catfches except i n the months of J u l y and August.  F i s h taken i n the l a t t e r  p a r t o f August were n e a r i n g the completion of  spawning.  To set a d e f i n i t e date at which spawning  i s completed  i s i m p o s s i b l e as no samples of a d u l t f i s h were o b t a i n e d betocc/urs  ween August and February. August  That some spawning^later than  c • ::,.; i s suggested.by a sample o f small immature f i s h ;  taken from B u r r a r d I n l e t i n December, 191+9•• f i s h ranged from 58 mm.  to 96 mm.  The s i z e of these,  A s i m i l a r sample o f p o s t -  l a r v a l f i s h from J e r v i s I n l e t taken September 12, i n s i z e from 1+9 mm. of comparable  to 89 mm.  191+7 ranged  The f a c t t h a t these two  samples  l e n g t h were taken three months apart may  reflect  a d i f f e r e n c e i n growth r a t e between y e a r s or between f i s h from different localities, spawning  or i t may  be the r e s u l t o f a p r o t r a c t e d  season.  Wherever e n g r a u l i d s have been s t u d i e d spawning has been found to occur w i t h i n c e r t a i n w e l l d e f i n e d temperature Few  limits.  l a r v a e are found w i t h i n a wide range or at low temperatures.  Spawning o f E n g r a u l i s e n c r a s i e h o l u s i n the Mediterranean occurs when the temperature i s about 1 7 . 8 ° C. and i n the North Sea w i t h i n a range of 18° C. to 22° C.  (Page, 1 9 3 7 ) .  The tem-  p e r a t u r e o f the water from which anchovy eggs are obtained o f f C a l i f o r n i a ranges from 1 1 . 1 °  C. to ll+.i+° C. where they are d i s -  t r i b u t e d w i d e l y both near shore and to seaward strom,  191+6).  (Smith and A h l -  The temperature range f o r spawning  on the  -33B r i t i s h Columbia coast seems to be s i m i l a r . f i s h i n 19ii7 were found  to be  B a r k l e y Sound  spawning i n J u l y and August when  the average seawater temperatures at A m p h i t r i t e P o i n t were 13.2°  C. and 11L.1° C. r e s p e c t i v e l y .  The p r o t r a c t e d spawning  p e r i o d f o r anchovy o f f C a l i f o r n i a as compared to the  relati-  v e l y short summer spawning p e r i o d i n B r i t i s h . C o l u m b i a i s r e temperatures (McHugh, 1950)•  l a t e d to v a r i a t i o n s i n seasonal Spawning  localities  Evidence  of s u c c e s s f u l spawning i n most bays and i n -  l e t s of Southern B r i t i s h Columbia i s shown by the  occurrence  of small immature f i s h ranging to about 1G0 m i l l i m e t r e s i n l e n g t h caught or seen during the w i n t e r months.  Adult  fish  appear o n l y o c c a s i o n a l l y a f t e r August and never i n l a r g e schools u n t i l February,  March, or A p r i l .  The  s i t u a t i o n i s probably  s i m i l a r to t h a t found i n the Mediterranean  where E n g r a u l l s '  e n c r a s l c h o l u s remains a l l w i n t e r near the coast, going deep w i t h marked temperature changes below 10°  C. to 12°  C.  In  the G u l f of Gascoigne, as on t h i s c o a s t , young i n d i v i d u a l s appear i n September and November. spawning and are seldom found Observations  The  a d u l t s disappear  during the winter  of anchovy movements made by  and f i s h e r i e s o f f i c e r s suggest  after  (Fage, 1937)* fishermen  t h a t f o l l o w i n g the spawning  p e r i o d the a d u l t s remain i n the bays and i n l e t s at depths f o r the winter months.  In B u r r a r d Inle t small schools of  c l o s e l y packed anchovy are seen along the shores In June July.  and  A f t e r August, schools of small f i s h are f r e q u e n t l y  seen, but the a d u l t s appear o n l y o c c a s i o n a l l y b e f o r e March  - k3  or A p r i l .  During the w i n t e r months, however, l a r g e schools  of u n i d e n t i f i e d f i s h are d e t e c t e d on echo sounders. f i s h may  be a d u l t  These  anchovy.  Por b o t h the European  and the A u s t r a l i a n anchovy  there  i s a tendency f o r spawning to occur i n e n c l o s e d waters i n h i g h e r l a t i t u d e s and out to sea i n lower l a t i t u d e s . the p r i n c i p a l  spawning a r e a was  the Zuy.der Zee, although some  eggs were found i n the open sea.  That spawning a l s o occurs  at sea o f f the c o a s t o f B r i t i s h Columbia  and Washington as  shown by the presence o f p o s t - l a r v a l anchovy from 80 to 200 m i l e s o f f s h o r e .  In the A t l a n t i c  In albacore caught  Samples of l k l anchovy  averag-  i n g 36 m i l l i m e t r e s i n l e n g t h were taken from a l b a c o r e stomachs i n J u l y and August,  19k7  and 19k8.  A sample of 23  from a l b a c o r e caught i n September, 19k8  anchovy  averaged $0 m i l l i m e t r e s  i-n l e n g t h . The o n l y r e f e r e n c e i n the l i t e r a t u r e to anchovy  spawn  i n B r i t i s h Columbia waters i s found i n a note by W i l l i a m s o n (1929) e n t i t l e d mentions  "The P i l c h a r d and i f s A s s o c i a t e s " .  The  the occurrence of f l o a t i n g oval-shaped anchovy  writer eggs  about l / 2 0 t h of an i n c h i n l e n g t h i n c e r t a i n i n l e t s of Vancouver I s l a n d .  -35V. SUMMARY AND CONCLUSIONS C o n s i d e r a t i o n s o f l e n g t h f r e q u e n c i e s , s c a l e readings and ova diameter measurements i n t h i s study have y i e l d e d c e r t a i n b a s i c b i o l o g i c a l i n f o r m a t i o n on the age, growth and m a t u r i t y o f the P a c i f i c anchovy i n h a b i t i n g the c o a s t a l waters  o f B r i t i s h Columbia.  The anchovy supports a small  f i s h e r y which I s l i m i t e d mainly by reason of marked annual f l u c t u a t i o n s i n abundance.  Commercial catches are charac-  t e r i z e d by one or two dominant year c l a s s e s .  Conclusions  reached i n the study by the a n a l y s i s o f commercial  catch  samples are as f o l l o w s . 1.  The P a c i f i c anchovy, E n g r a u l i s mordax G-irard, occurs throughout Columbia  2.  the c o a s t a l waters  of southern B r i t i s h  as f a r n o r t h as Ogden Channel.  Female anchovy grow s l i g h t l y f a s t e r than do the males. The females a t t a i n average  l e n g t h s o f approximately  107, 128, lkO, l k 9 and 157 mm. of age. Males a t t a i n average 105,  126, 138, l k 6 and 153 mm.  a t 1,  2, 3 , k and 5 years  l e n g t h s o f approximately a t the same ages.  Most  of the growth occurs d u r i n g the s p r i n g and summer months. 3.  The maximum l e n g t h of females i s l 6 8 mms.  and of males  153 mms.., r e p r e s e n t i n g ages o f 7 and 6 years r e s p e c t i v e l y . Few anchovy, o l d e r than k y e a r s o f age appear i n c : commercial  catches.  -36-  1L.  Commercial catches consist mainly of 2nd and 3rd year fish.  First year fish do not join the adult  schools until June, July or later. 5.  The proportion of males to females i s approximately 1+5 to 55 ^  n  samples from a l l years and localities  during the spring months. At the approach of spawning in June or July the sex ratio approaches parity. During the e arly part of the spawning period males predominate in most of the catches with a ratio of . 55:li5.  6.  A progressive increase i n the weight-length relationship associated with the maturation of the gonads occurs throughout the spring months in both males and females.  Females are relatively heavier than  males at any given length and Increase in weight with increasing lengths more rapidly than do the males. 7.  Spawning occurs i n most of the bays and inlets of southern British Columbia during la te June, July and August.  Spawning occurs up to 200 miles off the at  Washington coast*,this same time of year. 8.  The majority of female anchovy mature in the 2nd year, but some may mature in the f i r s t year.  The situation  appears to be similar for the males. 9.  Growth of the ova to maturity commences in February and March in adult females of a l l sizes and from a l l localities.  By June the majority of females have matured  three batches of ova preparatory to spawning.  - -3710.  M u l t i p l e spawnings o c c u r i n female a n c h o v y .  It i s believed that  a minimum average o f 144,000 eggs i s spawned i n t h r e e o r more b a t c h e s each y e a r .  Mature o r m a t u r i n g ova a r e not c a r r i e d o v e r  i n t o succeeding years.  -38-  V I . ACKHOWLEDG^IENTS. S p e c i a l thanks are expressed t o D r . J « L . H a r t , D i r e c t o r of t h e P a c i f i c B i o l o g i c a l S t a t i o n , who suggested t h e problem and gave p e r m i s s i o n f o r t h e anchovy m a t e r i a l t o be s t u d i e d as a t h e s i s . a u t h o r g r a t e f u l l y acknowledges t h e h e l p and encouragement  The  given him  by P r o f e s s o r W.A. Clemens, Head of t h e Department o f Z o o l o g y , and by P r o f e s s o r W . S . H o a r , under whose d i r e c t i o n t h e m a n u s c r i p t was p r e p a r e d . Catch samples were o b t a i n e d t h r o u g h t h e c o u r t e s y o f N o r t h . Shore P a c k e r s , B . C . P a c k e r s and F r a n c i s M i l l a r d f i s h i n g companies. i n c o l l e c t i n g t h e samples was k i n d l y rendered by F i s h e r i e s J.O.  Lake.  Assistance  Inspector  -39V I I . LITERATURE CITED  Bolin,  R.L.  193&.  Embryonic the  and e a r l y l a r v a l  California  anchovy,  mordax G i r a r d . C a l i f . Pish. Blackburn,  M.  1950.  Engraulls  P i s h Game Comm.,  (22) :31[t-321.  Bull.  A biological Engraulis  stages o f  study  australis  o f t h e anchovy ( W h i t e ) i n Aus-  t r a l i a n w a t e r s . A u s t . J . Mar. F r e s h -  1  w a t e r Res. Clark,  P r a n c e s N.  1931.  Maturity  (l):3-8ii.  of the C a l i f o r n i a  (Sardina caerulea)  determined by ova  d i a m e t e r measurements.  Calif.  1937.  L a ponte e t l e s races l a Mediterranee lus)L.).  de l ' a n c h o i s de  (Engraulis  Comm. I n t e r n a t .  encrasichoExplor.  S c i e n t i f i q u e Mer M e ' d i t e r r a n e e . ports  £ Hildebrand,  :67-71.  S.F. 19ij-3». A r e v i e w o f t h e A m e r i c a n  Oceanogr. C o l l . J.P.  1949.  Rap-  e t p r o c e s - v e r b e a u x des r e u n i o n s .  (family Engraulidae).  Harding,  Pish  (Ii2) : l - i | 9 .  Game Comm., P i s h . B u l l . Fage, L .  sardine  anchovies,  Bull.  Bingham  New Haven. _8 (2) 1-165.  The u s e o f p r o b a b i l i t y p a p e r f o r t h e graphical  a n a l y s i s o f polymodal  quency d i s t r i b u t i o n s . Ass.  United  fre-  J . Mar. B i o l .  Kingdom. 28 (1) : L l i l - l 5 3 .  -ko-  Hubbs, C a r l L .  1925.  Racial  and s e a s o n a l v a r i a t i o n i n t h e  pacific  anchovy.  C a l i f . P i s h Game  Comm., P i s h . B u l l . J o r d a n , D.S. and A. S e a l e .  1 9 2 6 . Review o f t h e E n g r a u l i d a e ,  with descriptions Bull. McHugh, J . L .  1950«  Variations  .ogr.  Scripps  191+6.  i n the s p r i n g  1 9 k 8 . The l i f e  villosus  Tester,  A r t h u r L.  central  o f 19k6.  O.P. M u l l e r ) Bull.  MS.  Nfld.  i n NewGovt.  herring  and age c o m p o s i t i o n o f (Clupea p a l l a s l l ) ,  c o a s t a l waters o f B r i t i s h J.  on t e m p e r a -  (17):l-l5l.  The l e n g t h the  fish  h i s t o r y of the capelin  foundland waters.  1937*  Ocean-  and p l a n k t o n i n w a t e r s o f f  (Mallotus  Arthur L.  Inst.  Echo-sounding f o r  and o b s e r v a t i o n s  California  Tester,  i n the  MS.  schools  Lab.  species.  68 (2):355-1+18.  and p o p u l a t i o n s  anchovy.  S m i t h , O.R. a n d E.H. A h l s t r o m .  ture  o f new and r a r e  Mus. Comp. Z o o l .  pacific  Templeman, W i l f r e d .  (8):13-21.  B i o l . Bd. Can. £  1 9 3 7 . Popula t i o n s  i n the  Columbia.  (2):lk5-l68.  of herring  (Clupea  pal-  l a s l l ) i n the c o a s t a l waters o f B r i tish  Columbia.  .(2):108-lkk.  J . B i o l . ® d . Can. ^  -if.1-  Walford, L.A.  191+5*  F i s h e r i e s resources of the U n i t e d S t a t e s of America.  U.S. F i s h Wild-  l i f e Serv. 1-135. Williamson, H.C.  1929. The p i l c h a r d and it's a s s o c i a t e s . Mus. A r t Notes,  ij. (13) : 1 0 5 - 1 0 8 .  -k2V I I I . APPENDIX A D e t a i l s o f c a t c h samples used i n the study. DATE'  LOCALITY  NO. MEASURED  26/ 5 A ©  Departure Bay  121  a  20/ 5 A i  Departure Bay  100  a  2/ 6 / k i  B a r k l e y Sound  155  6/ 8 / k i  B a r k l e y Sound 11 samples B a r k l e y Sound  7kk8  3/ 9/kl 20/1l/kl  Pender Harbour  SEXES SEI  $j  100 92  303  5 / 2/k7  B a r k l e y Sound . 3 samples Departure Bay  15/ 2/k7  Departure Bay  135  ii  17/ 2/k7  Departure Bay  122  \i  21/ 2/k7  Departure Bay  115  ii  17/ 3 A 7  Burrard I n l e t  116  ii  20/ 3 A 7  Burrard  Inlet  156  B a r k l e y Sound  100  ~t\  3/HA3  2/ 4/k7  152  »»  f\  .  a  13/  4A7  B a r k l e y Sound  116  •ii  15/  kA7  Burrard I n l e t  110  •it*  17 k/k7  B a r k l e y Sound  130  ii  19/  4A7  B a r k l e y Sound  99  a  16/  5A7  Effingham  Inlet  129  a  17/  5A7  Effingham I n l e t  101  %i  18/  5A7  Effingham I n l e t  82  19/  5A7  Burrard I n l e t  139  21/  5A7  B a r k l e y Sound  121  1/ 6/k7  B u r r a r d Inle t  101  ii  Smiths I n l e t  lk2  ii  17/ 6/k7  a  A3V I I I . APPENDIX A  NO. MEASURED  LOCALITY  DATE  (cont'd).  20/ 6/Ii7  Burrard  20/ 6/LL7  Effingham  26/ 6A7  Smiths  Inlet  11+1  2 7 / 6/It7  Smiths  Inlet  113  Inlet Inlet  11+9  Burrard  Inlet  133  9/ 7A7  Barkley  Sound  137  20/ 8A7  Seehelt  Inlet  116  28/ 8 A 7  Sechelt  Inlet  !31,  12/ 9A7  Jervis  16/ 6/ii8  Sechelt  Inlet  131  22/ 6/1+8  Sechelt  Inlet  158  23/:6A8  Barkley  Sound  118  6/I18  Burrard  Inlet  113  6 A 8  Sechelt  Inlet  223  2k/  30/  Effingham  8/ 7 A 8  Sechelt  Inlet  170  15/ 7 A 8  Sechelt  Inlet  188  Inlet  160  17/ 1+/1+9  Barkley  Sound  161  17/12A9  Burrard  Inlet  23  111/ 2/50  Malaspina  23/ 7 A 7  100-180 m i l e s o f f  19/ 8 A 7  Washington  6-10/  SO-100 m i l e s o f f Washington  Inlet  •5!-  159  21  Coast  Coast  -a  11+9  Redonda Bay  8A8  -a  60  Inlet  k/ 7 A 8  5/10/1+8  -/a  117  6/ii7  29/  SEXES SEPARATE  120  from a l b a c o r e stomachs n  -kkV I I I . APPENDIX A DATE 18/  9/1+8  LOCALITY 80 m i l e s  (cont'd). NO. MEASURED  SEXES SEPARATE  S.W. 23  Cape B l a n c o  from a l b a c o r e stomachs  

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