UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

The effect of fin-clipping on the cruising speed of goldfish (Carassius auratus L.) & cohoe salmon fry… Radcliffe, Roland Wootton 1949

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1949_A8 R23 E4.pdf [ 2.22MB ]
Metadata
JSON: 831-1.0107011.json
JSON-LD: 831-1.0107011-ld.json
RDF/XML (Pretty): 831-1.0107011-rdf.xml
RDF/JSON: 831-1.0107011-rdf.json
Turtle: 831-1.0107011-turtle.txt
N-Triples: 831-1.0107011-rdf-ntriples.txt
Original Record: 831-1.0107011-source.json
Full Text
831-1.0107011-fulltext.txt
Citation
831-1.0107011.ris

Full Text

LB $ ft f THE EFFECT OF FIN-CLIPPING ON THE CHUISING SPEED OF GOLDFISH ( CARASSIUS AURATUS L.) & COHOE SALMON FRY (ONCORHYNCHUS KISUTCH WALBAUM) A THESIS SUBMITTED IN- PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ARTS IN the Department of ZOOLOGY THE UNIVERSITY OF BRITISH COLUMBIA A p r i l , 1949 ROLAND WOOTTON RADCLIFFE ABSTRACT - @ o l i f i . s l i (Carasaias a a ^ a t u s L.) aaft eolioe' s a l m o n f£Sr ( Q n c o r h y a o a u s . M s o t s f e f&lbauff l ) weage a e c l i i a a t i z e d t o £0*0. and 3 ° C . r©sp' .©otlvely, . The f i s h w ^ r e p l a c e d one a t a t i m e one© a d a y f o r t e n d a y s i n a r o t a t i n g a n n u l a r chamber sad the c r u i s i n g s p e e d was f o u n d . Then v a r i o u s f i n c o m b i n a t i o n s were c l i p p e d o f f and t h e f i s h were g i v e n t e n a o r e t r i a l s . The a©an c r u i s i n g s p e e d s b e f o r e and a f t e r c l i p p i n g w e r e co japared* Th© c l i p p e d f i a h s u f f e r e d no l o s s I n a b i l i t y t o swim a t a c o n s t a n t r a t e * C r u i s i n g - s p e e d and l e n g t h , and c r u i s i n g spe&d and w e i g h t o f c l i p p e d and u n c l i p p e € g o l d f i s h w e r e c o r r e l a t e d . TABLE OF CONTENTS I n t r o d u c t i o n - - - - - - - - - - - - - - - - - - - i i Acknowledgment - - - - - - - - - - - - - - - - - - v l Apparatus and Methods - - - - - - - - - - - - - - l R e s u l t s - - - - - - - - - - - - - - - - - - - - - 7 D i s c u s s i o n - - - - - - - - - - - - _ _ _ _ _ _ 13 Figure 1 The apparatus - - - - - - - - - - - - - 2 2 Regression of C r u i s i n g Speed and Weight - 10 3 Regression of C r u i s i n g Speed and Length - 11 4 E x p l a n a t i o n of terms - - - - - - - - - - 17 5 Forces i n the V e r t i c a l plane - - - - - - 17 6 S t a b i l i t y without f i n s - - - - - - - - - 19 7 S t a b i l i t y w i t h median f i n s 19 8 Role of p e l v i c f i n s i n stopping - - - - 20 9 Path of f i s h stopping without p e l v i c f i n s 20 Table I P a r t i a l record of a f i s h - - - - - - - - 5 I I t values of g o l d f i s h - - - - - - - - - - 7 I I I t values of cohoe - - - - - - - - - - - - 8 IV Maximum crui s i n g - s p e e d of a g o l d f i s h f o r each t r i a l - - - - - - - - - - - - - - - 9 V Regression c o e f f i c i e n t s and f i d u c i a l l i m i t s 12 Appendix - - - - - - - - - - - - - - - - - - - - - 2 4 i The E f f e c t of F i n - C l i p p i n g on the C r u i s i n g Speed of G o l d f i s h (Carassius Auratus L.) and , Cohoe salmon f r y (Oncorhynchus k i s u t c h Walbaum). INTRODUCTION The removal of one or more f i n s from a f i s h i s a standard method of marking them f o r f u t u r e i d e n t i f i c a t i o n . • This procedure has been r e s o r t e d to i n three types of experiment. F i r s t , f i s h may be marked to determine morta-l i t y r a t e s - e i t h e r n a t u r a l m o r t a l i t y , f i s h i n g m o r t a l i t y or both. In t h i s case the r a t e at which the marked f i s h d i s -appear i s considered to be the m o r t a l i t y r a t e f o r the popu-l a t i o n . Second (samples of f i s h may be marked to determine the s i z e of the p o p u l a t i o n . In t h i s case a known number of marked f i s h are r e l e a s e d and a f t e r s u f f i c i e n t time has elapsed f o r t h e i r mixing i n the p o p u l a t i o n , samples are taken to o b t a i n the r a t i o of marked to unmarked f i s h . A simple c a l c u l a t i o n f i x e s the s i z e of the p o p u l a t i o n . I n the t h i r d p l ace f i s h may be marked to determine t h e i r migrations or d i s t r i b u t i o n , although f o r t h i s purpose tagging experiments are u s u a l l y used. Any m o r t a l i t y caused by the marking procedure w i l l produce i n a c c u r a c i e s i n the a n a l y s i s of the r e s u l t s , unless adequate adjustments are made. There are, at l e a s t , two sources of m o r t a l i t y from marking. F i r s t there may be death from the a c t u a l process of f i n c l i p p i n g caused by rough e> - • handling;, b a c t e r i a l i n f e c t i o n of the wound, or l o s s of body f l u i d s . The second may r e s u l t from."a. l o s s o f the f i s h ' s a b i l i t y to maintain i t s e q u i l i b r i u m , to swim or to maneuver so t h a t i t i s more e a s i l y caught by p r e d a t o r s or i s not able to catch i t s own food. Death from the f i r s t cause i s r e a d i l y checked by an adequately c o n t r o l l e d exper-iment i n which f i s h are placed i n a pond f r e e o f t h e i r predators ard". the m o r t a l i t y i s compared w i t h a group of c o n t r o l f i s h . The r e s u l t s of such experiments show t h a t f i s h w i t h a f i n or f i n s removed s u f f e r no greater m o r t a l i t y than non-m u i i l a t e d c o n t r o l s (Ricker, 1949). Death r e s u l t i n g from disturbances i n e q u i l i b r i u m i s more d i f f i c u l t to determine since the marked f i s h are not kept i n c a p t i v i t y . To the author's knowledge onl y two experiments have been c a r r i e d out t o determine whether there was a d i f f e r e n -t i a l m o r t a l i t y between marked and unmarked f i s h i n t h e i r n a t i v e h a b i t a t . One of these experiments was performed by F o e r s t e r (1936) at Cultus Lake, B.C. He marked p a r t of the young sockeye l e a v i n g the la k e i n two years and found on the b a s i s of tha r e t u r n s of marked and unmarked f i s h t h a t there was approximately an e x t r a 62 percent m o r t a l i t y i n the ocean among marked i n d i v i d u a l s . The f i n s removed f o r i d e n t i f i c a t i o n were both v e n t r a l f i n s the f i r s t year and both v e n t r a l s and adipose i n the second. This experiment has been c r i t i c i z e d by several authors (Ward, 1939) but i t i i i probably i n d i c a t e s that there i s an increased m o r t a l i t y among marked f i s h i n the ocean. The second experiment was done by R i c k e r (1949). He stocked ponds w i t h three species of f i s h attempting to b b t a i n a n a t u r a l balance between species and i n c l u d i n g both marked and unmarked f i s h . The species used were largemouth bass (Huro salmoides), adult b l u e g i l l and redear s u n f i s h (Lepomls macrochftnus and L. microlophus) and y e a r l i n g perch (Perca f l a v e s e e n s ) . He used the f o l l o w i n g combinations of c l i p p e d f i n s : l e f t v e n t r a l , r i g h t v e n t r a l , both v e n t r a l s , l e f t p e c t o r a l , l e f t p e c t o r a l and l e f t v e n t r a l . He found an increased m o r t a l i t y of 48 percent i n the young bass. The other species of marked f i s h d i d not seem to s u f f e r any increa s e d m o r t a l i t y . Among the young bass those w i t h two or more f i n s removed had an e x t r a m o r t a l i t y of 12.0 percent over those w i t h one f i n removed. The t o t a l m o r t a l i t y was too small to consider these f i g u r e s c o n c l u s i v e . From these experiments i t seems probable t h a t , f o r c e r t a i n s p e c i e s , the removal of f i n s (from young f i s h ) does have some adverse e f f e c t on the f i s h ' s a b i l i t y to adapt i t s e l f to i t s e n v i r o n -ment. The experiments undertaken i n t h i s study were de-signed t o i n v e s t i g a t e the e f f e c t of f i n - c l i p p i n g on the c r u i s i n g speed as a measure of a c t i v i t y of the f i s h . In a d d i t i o n an attempt has been made to c o r r e l a t e the c r u i s i n g speed w i t h the weight or standard l e n g t h . T h e " c r u i s i n g -speed" has been defined as, "that speed at which the f i s h i v could swim s t e a d i l y f o r some considerable p e r i o d of time, although presumably a f t e r hours f a t i g u e would set i n " (Fry and Hart, 1 9 4 8 ) . ACKNOWLEGMENT The author would l i k e to express his- a p p r e c i a t i o n t o Dr. W.A. Clemens, head of the Department of Zoology: to Dr. W.S. Hoar under whose d i r e c t i o n the work was i n i t i a t e d and who gave most generously of h i s time and advice: to Dr. l . C . Black f o r loan of the apparatus and f o r valuable suggestions: to Dr. R.E. F o e r s t e r and Mr. F. Neave of the P a c i f i c B i o l o g i c a l S t a t i o n * Nanaimo, B.C. who supplie d a l i s t of f i n s most commonly c l i p p e d f o r marking purposes on the P a c i f i c Coast: and to the graduate students of Hut M»30 who provided s t i m u l a t i o n and a s s i s t a n c e on many occasions. v i 1. APPARATUS AND METHODS The c r u i s i n g speed was measured by means of a • r o t a t i n g annular chamber tsimilar to the one used by E r y and Hart (194$). The inner w a l l and f l o o r were made of metal and the outside w a l l was of g l a s s . The outside d i a -meter was 30.48 centimeters (twelve inches) and the i n s i d e diameter of 15.24 centimeters (6 i n c h e s ) . The tank was 15*24 centimeters ( 6 inches) deep w i t h an overflow s i t u -ated so as to maintain the water l e v e l at 12.70 centimeters ( 5 i n c h e s ) . The chamber was s u p p l i e d w i t h running aerated water at a constant temperature from a r e s e r v o i r . The chamber was r o t a t e d by a o n e - t h i r d horse power e l e c t r i c motor through a Graham model 41B r e d u c t i o n gear w i t h an input of 3600 r.p.m. and a v a r i a b l e output, con-t r o l l e d by a micrometer c o n t r o l , from 0-»650 r.p.m. over an i n f i n i t e s e r i e s of steps. When the chamber was r o t a t e d the f i s h swam i n a d i r e c t i o n opposite to the r o t a t i o n of the drum and maintained a f i x e d p o s i t i o n r e l a t i v e to the room. A lamp was placed on one side of the r o t a t i n g chamber f i v e centimeters from the outer w a l l i n the mid-., l i n e to a i d the animal i n o r i e n t i n g i t s e l f . This pseudo* r h e o t r o p i c response was e l i c i t e d mainly by the short r a d i u s of curvature of the tank and to a l e s s e r extent by the '4. o p t i c a l stimulus of the l i g h t (Gray* 1937). A thermometer suspended i n the water may have acted as a n ' a d d i t i o n a l stimulus ( f i g . 1). RESERVOIR LIGH THERMOMETER ROTATING DRUM MICROCONTROL =K REDUCTION GEAR MOTOR F i g * 1. The A p p a r a t u s . The r a t i o of the speed of the drum to the speed of the water over the range used f o r the experiments was con-stant so speeds w i l l be st a t e d i n r e v o l u t i o n s per minute, since i t i s the r e l a t i v e speeds before and a f t e r c l i p p i n g that are of i n t e r e s t and not the absolute v a l u e s . . The procedure fo l l o w e d i n t e s t i n g a f i s h was as f o l l o w s . The f i s h was put i n the chamber which was r o t a t e d at a slow speed f o r 12 minutes. The m i c r o c o n t r o l of the r e d u c t i o n gear was set a t 1.5 which gave a speed of a p p r o x i -mately 20 r.p.m. f o r t h i s i n i t i a l p e r i o d . F r y and Hart (1948) recommend! s t i m u l a t i n g the f i s h w i t h a g l a s s rod durin g t h i s warm up p e r i o d i f they f a l l back beyond a c e r -t a i n p o i n t . They do not s t a t e how long the f i s h are per-m i t t e d to remain at t h i s slow speed. Presumably i t was f o r a con s i d e r a b l y l e s s time than 12 minutes, since i t was un-necessary, to s t i m u l a t e the f i s h r o t a t i n g f o r t h i s l e n g t h of time to make them swim s t e a d i l y . No r e c o r d was kept i f l a p s were l o s t during the i n i t i a l o r i e n t a t i o n time. A f t e r 12 minutes the speed was increased by 0.5 u n i t s of the micro-c o n t r o l (approximately 8 r.p.m,) and each succeeding two minutes i t was increased by the sams amount u n t i l the f i s h began to l o s e l a p s . Then, the apeed was reduced by 0.1 u-n i t s at two minute, i n t e r v a l s u n t i l the f i s h could j u s t maintain i t s p o s i t i o n . The number of r e v o l u t i o n s was now counted using a stop watch and t h i s was taken as the c r u i s -i n g speed. Each t r i a l l a s t e d from 25 to 30 minutes. Since temperature v a r i a t i o n s produce changes i n v i s c o s i t y of the 4 . o i l i n the reduction.gear, s l a c k i n the mechanism and power f l u c t u a t i o n s , the same s e t t i n g of the m i c r o c o n t r o l d i d not always give e x a c t l y the same speed* Consequently the f i n a l c r u i s i n g speed was always checked w i t h a stop watch. The p a r t i a l data on one f i s h i s given i n Table I . The g o l d f i s h were obtained from the G o l d f i s h Supply Co., S t o u f f v i l l e , Ontario and a c c l i m a t i z e d to a temperature of 20°C. f o r three weeks before being used f o r the e x p e r i -ments . They were fed de s s i c a t e d l i v e r and pablum. The water used to make the t r i a l s was also kept at 20° C. Each f i s h was given three p r e l i m i n a r y t r i a l s , one day apart to reduce c o n d i t i o n i n g e f f e c t s , i f any, as much as p o s s i b l e . No record of these t r i a l s was kept. Then each f i s h was te s t e d once per day f o r ten days. Following t h i s f i n s were cut o f f i n various combinations (Tables I I and I I I ) . Four f i s h were marked for each combination. The c l i p p e d f i s h were then g i v e n one t r i a l each day f o r another ten-day-period and the mean c r u i s i n g speeds of each f i s h before and a f t e r being c l i p p e d were compared. The Cohoe f r y were t r e a t e d i n the same general manner except they were kept i n a trough of running water at 3°C. and were r o t a t e d i n water at 5°C. They were f e d fr o z e n l i v e r . Two cohoe were marked f o r each combination. C o n t r o l f i s h o f both species were g i v e n d a i l y t r i a l s f o r the second ten-day p e r i o d , and the mean c r u i s i n g speeds were compared as i n the case of c l i p p e d f i s h . TTable I . P r o t o c o l ' of p a r t of the r e c o r d of one g o l d f i s h "before b e i n g c l i p p e d . F/ish Number 9> 5.2 g.,5.7 cm. 2: d6 30 p.m. -12-48 1:30 p^m. 17-12-48 11:45 p.m. 18-12-48 11: . . ^ 15 a.m. -12-48 4: 20 15 p.m. -12-48 S e t . Time Laps M i n . L o s t S e t . Time Laps M i n . L o s t S e t . Time M i n . Laps L o s t S e t , Time Min.. La,ps L o s t S e t . Time Laps Min.. L o s t 1.5 12 1.5 1? 1«5 12 1.5 -12 1.5 12 2.0 2 2.0 2 2.0 2 2.0 2 2.0 2 2.5 22 2.5 2 2.5 2 2 . 2.5 2 2.5 2 3.0 2 2 3.0 2 2 3.0 2 3 3.0 2 3.0 2.9 2 2.9 2 2.9 2 2 3.5 2 3 3.5 2 3 2.8 2 2 3.4 2 3 3.4 2 2 2 a7 2 3-3 3.2 3.1 3.0 2 2 2 2 2 2 2 3.3 3.2 3.1 2 2 2 2 2 4:8„9"". R.P..M.. 46.7 R.P.M. 44.8 R.P.M. 50.0 R.P.M. 51.7 R.P.M, 6 The f i n combinations were those most commonly used f o r marking on the P a c i f i c Coast; anal and r i g h t v e n t r a l , d o r s a l and l e f t v e n t r a l , d o r s a l and r i g h t v e n t r a l , both v e n t r a l s , d o r s a l and both v e n t r a l s , anal and r i g h t p e c t o r a l . 7 RESULTS The r e s u l t s of the experiments are summarized i n Tables I I and I I I . The complete data of each d a i l y t r i a l f o r each f i s h are on f i l e i n the department of Zoology, U n i v e r s i t y of B r i t i s h Columbia. The maximum c c u i s i n g speed of each d a i l y t r i a l i s given i n the appendix together with the weight and l e n g t h o f the f i s h . Table I I . Comparison of the mean c r u i s i n g speeds before and a f t e r marking g o l d f i s h . A - a n a l ; B - both; D- d o r s a l ; L- l e N f t ; P-pector a l ; R - r i g h t ; V- v e n t r a l . * ?ish No Mean be for* Marking (X Ten T r i a l s 3 Mean a f t e r ) Marking(XJ Ten T r i a l s Type of Marking X v- X, s t 16 36.02 rpm 1 38.14 rpm ARV -2.12 5.54 0.383 17 79.11 70.61 ARV > 8.50 11.20 0.758 14 52.08 59.46 ARV -7.38 8.34 0.886 15 59.71 55.74 ARV 3.97 8.64 0.459 9 51.28 63.60 DLV -12.32 8.64 1.430 11 57.68 60.28 DLV -2.60 8.70 0.298 7 66.61 65.13 DLV 1.48 9.74 0.148 8 58.21 53.06 DLV 5.15 8.33 0.618 12 54.74 53.26 DRV 1.48 8.50 0.174 13 78.87 72.12 DRV 6.75 11.29 0.599 6 55.02 53.93 DRV 1.09 8.11 0.134 10 80.76 77.89 DRV 2.87 11.6 0.246 SO 55.45 71.42 BV -15.87 9.51 1.686 19 62.16 58.36 BV 3.80 8.99 0.423 4 59.53 61.60 BV -2.07 9.04 0.229 18 48.50 • 50.93 BV -2.43 7.41 0.328 8 F i s h No. Mean before Marking(X^} Ten T r i a l s Mean a f t e r Marking ( X j Ten T r i a l s Type of Marking X.-X s t 1 57.49 rpm 55.39 rpm DBV 2.00 8.41 0.238 2 60.51 49.29 DBV 11.22 8.22 1.361 3 65.59 59.49 DBV 6.10 - 9.34 0.654 5 58.04 60.97 DBV -2.93 8.86 0.331 21 71.27 68.97 ARP 2.30 10.45 0.220 26 73.10 75.45 ABP -2.35 11.05 0.212 27 59.61 63.34 ARP -3.73 9.20 0.405 30 68.42 64 ."29 ARP 4.13 9.90 0.418 22 74.28 66.54 Con t r o l 7.74 10.51 0.774 23 67.28 68.40 C o n t r o l -1.34 10.15 0.132 24 62.58 76.09 Co n t r o l -13.51 10.40 1.357 25 58.07 59.17 Co n t r o l -1.10 8.75 0.125 28 63.48 80.35 Co n t r o l -16.87 10.70 1.565 29 57.00 64.58 C o n t r o l -7.58 9.10 0.834 * A l l s t a t i s t i c a l symbols from Snedeco.r, G. S t a t i s t i c a l Methods, 1940 Table I I I . The comparison of the mean c r u i s i n g speeds before and a f t e r marking cohoe f r y . The same abb r e v i a t i o n s are used as i n Table I . F i s h No. Mean before Marking (X,) Ten T r i a l s Mean a f t e r Marking ( X j Ten T r i a l s Type of Marking X,- X a s t 33 34 66.28 rpm 65.65 64.44 rpm 59.42 BV BV 1.84 6.23 9.75 9.34 0.188 0.624 35 42.37 51.15 DRV -8.78 7.00 1.250 36 61.43 62.88 DRV -1.45 9.25 0.156 31 . 32 69.29 52.23 69.55 49.17 C o n t r o l C o n t r o l -0.26 3.06 7.32 7.55 0.035 0.406 9 Table IV. T y p i c a l p r o t o c o l of the maximum c r u i s i n g speed of a g o l d f i s h f o r each t r i a l . F$sh Number 9, 5.2 gm., 5.7 cm. T r i a l Before T r i a l A f t e r C l i p p i n g C l i p p i n g DLV 1 48.9 1 52.6 2 46*7 2 63.8 3 44.8 3 58.9 4 50.0 4 60.0 5 51.7 5 81.0 6 46.2 6 66.6 7 52.6 7 68.2 8 65.4 8 60.0 9 50.0 9 65*4 • 10 56.5 10 59.5 The r e s u l t s are e n t i r e l y negative. The t_t values given i n Tables I I and I I I show t h a t there i s no d i f f e r e n c e i n mean c r u i s i n g speed o f marked and'unmarked f i s h . T h i s was true f o r f i s h immediately a f t e r marking and ten days l a t e r (Table I V ) . T-hie-vtable a l s o shows the day t o day unaccountable v a r i a t i o n i n c r u i s i n g speed which was tru e of both t h e g o l d f i s h and cohoe. The r e s u l t s show a p o s i t i v e r e l a t i o n s h i p between the c r u i s i n g speed and l e n g t h ^ and the c r u i s i n g speed and weight^ V(Table V, f i g s . 2 and 3 ) . 10 4 5--F i g . 2.AbsQissa:.. weight i n grams, o r d i n a t e speed i n R.P.M., x and s o l i d l i n e g o l d f i s h before c l i p p i n g , o and broken l i n e a f t e r c l i p p i n g . 1 1 3 5 i 1 1 1 1 * 5 6 7 8 F i g . 3. A b s c i s s a , . standard l e n g t h i n centimeters, ordinate speed i n K C P . M . , x and s o l i d l i n e g o l d f i s h before c l i p p i n g , o and broken l i n e a f t e r c l i p p i n g . 12 Table V» Summary of s t a t i s t i c a l data showing c o r r e l a t i o n s of c r u i s i n g - s p e e d and' weight . t r'cruising-speed and l e n g t h of g o l d f i s h . Before C l i p p i n g A f t e r C l i p p i n g b F i d u c i a l L i m i t s t b F i d u c i a l L i m i t s t Cruising-speed and We i g h t 1.04 2.02 to Q..Q6 2.16 1.84 2.50 to 0.98 3.71 C r u i s ing-speed and Length 3-38 6.29 to 0.47 2.38 4.90 7.60 to 2.20 3.57 13 DISCUSSION The a n a l y s i s of the mean c r u i s i n g speed by the t t e s t of s i g n i f i c a n c e c l e a r l y shows that the c l i p p i n g of two f i n s has no e f f e c t on the c r u i s i n g speed of e i t h e r g o l d f i s h or cohoe f r y . T h e i r a b i l i t y to swim at a steady speed f o r a considerable time i s not a f f e c t e d . Some of the mean speeds a f t e r the c l i p p i n g were higher but an equal number of f i s h had a decrease i n t h e i r mean speeds. Fu r t h e r the d i f f e r -ences i n the c o n t r o l s were of. the same order as the ex-* perimental f i s h . The standard d e v i a t i o n s i n d i c a t e a con s i d e r a b l e v a r i a b i l i t y i n the c r u i s i n g speed of each t r i a l . Over the p e r i o d of twenty t r i a l s a consistency of c r u i s i n g speed was never obtained. A f i s h would show a f a i r l y c o n s i s t a n t speed f o r a few days and then i t would change r a d i c a l l y f o r no apparent reason. No f i s h showed consistency f o r the whole twenty t r i a l s . The time of day or the time of t r i a l r e l a t i v e to feeding seemed t o make no d i f f e r e n c e , n e i t h e r d i d the r e l a t i v e number of the t r i a l s or the day of the month appear to make any c o r r e l a t i o n w i t h the changes* . -There are two p o s s i b i l i t i e s to account f o r the nega-t i v e r e s u l t s , e i t h e r the apparatus was inadequate or the m u t i l a t i o n had no e f f e c t on steady swimming. Considering the f i r s t p o s s i b i l i t y , the f i s h may not be st i m u l a t e d to swim maximally at each t r i a l or at any t r i a l . The con-d i t i o n s of l i g h t , temperature and the method of i n c r e a s i n g 14 the speed were kept constant i n a l l t r i a l s , so i t can only be presumed the f i s h were e q u a l l y s t i m u l a t e d f o r each t r i a l . Although i t i s not known how much e f f o r t the f i s h i s p u t t i n g f o r t h and there i s a v a r i a t i o n i n d a i l y t r i a l s , t h i s appar-atus provides, a good method of comparing an animals a c t i v -i t y under c o n t r o l l e d c o n d i t i o n s . The r e s u l t s of t b i s study are i n accord w i t h Gray's (193^) a n a l y s i s of f i s h locomotion. He says that the movement of a f i s h through the water i s caused by contrac-t i o n waves passing a l t e r n a t e l y down each s i d e o f the body. He showed the t a i l of the w h i t i n g (Gadus merlongus) s u p p l i e s 40% of the p r o p u l s i v e power and the body o s c i l l a t i o n s the remainder* I f the caudal f i n i s removed the f i s h compen-sates by i n c r e a s i n g the o s c i l l a t i o n of the p o s t e r i o r p a r t of the body and by moving a l a r g e r p a r t of the body. Whether f a t i g u e sets i n sooner i n such a f i s h i s not s t a t e d * C l i p p i n g the f i n s w i l l reduce the weight of a f i s h a s l i g h t amount and a l s o remove some of the drag, p r o v i d -in g the f i n i s amputated cl o s e to the body. Hence i t i s conceivable an increase i n c r u i s i n g speed could r e s u l t from c l i p p i n g the f i n s . A l s o observation of swimming g o l d f i s h and salmon shows that yC keeps fcts f i n s c l o s e against the body. No s i g n i f i c a n t d i f f e r e n c e was noted i n the., speed i f a t r i a l was run immediately a f t e r c l i p p i n g . Table V shows that the f i d u c i a l l i m i t s of the r e -g r e s s i o n c o e f f i c i e n t s before and a f t e r c l i p p i n g overlap. The t values show the r e g r e s s i o n c o e f f i c i e n t i s s i g n i f i c a n t 15 below the 5 percent l e v e l . The overlapping of the f i d u c i a l l i m i t s adds a d d i t i o n a l evidence to show there i s no d i f f e r -ence i n the c r u i s i n g speed owing to f i n c l i p p i n g . Regres-s i o n c o e f f i c i e n t s for the cohoe are not g i v e n , since the sample i s s m a l l . I t has been shown f o r several species that the a c t u a l process of amputating the f i n s causes no increase i n m o r t a l i t y i f the f i s h are held i n ponds f r e e of p r e d a t o r s (Rioker, 1949). There i s no reason that they should d i e from t h i s cause i n t h e i r n a t u r a l h a b i t a t , i f i t too i s f r e e of predators. The only other f a c t o r s not considered are the e f f e c t g o f f a t i g u e and e q u i l i b r i u m . Since the f i s h i s ob-served to swim at a constant r a t e w i t h i t s f i n s c l o s e d , there should be no f a t i g u e e f f e c t , so the only f a c t o r un-explored i s e q u i l i b r i u m . E q u i l i b r i u m e f f e c t i s g r e a t e s t when the animal i s t u r n i n g , a c c e l e r a t i n g or d e c e l e r a t i n g , and performing combinations of these maneuvers. From the a n a l y s i s of the r o l e f i n s p l a y i n s t a b i l i t y and c o n t r o l , i t seems probable that t h i s f a c t o r p l a y s a l a r g e p a r t i n any increased " m o r t a l i t y of marked f i s h . H a r r i s (1936,37,38) has shown exp e r i m e n t a l l y and t h e o r e t i c a l l y the f u n c t i o n of the f i n s i n maintaining e q u i l i b r i u m and the consequences of c u t t i n g o f f c e r t a i n f i n s . The experimental work was, done by making a p l a s t e r cast of the f i s h w i t h a d j u s t a b l e wax f i n s and p u t t i n g the model i n a wind t u n n e l . The r e s u l t s are described i n conventional aerodynamic terms. This type of a n a l y s i s i s mathematically 16 j u s t i f i e d by the use of Reynold's' number. Further s t u d i e s were made by t a k i n g motion p i c t u r e s of the swimming f i s h . Both types of data were t r e a t e d mathematically and the wind tunnel r e s u l t s agreed w i t h the motion p i c t u r e r e s u l t s . The terms shown i n f i g u r e s 4 and 5 w i l l be used i n the d i s c u s -s i o n of s t a b i l i t y that f o l l o w s . The center of pressure (C.P.) i s the p o i n t where the ' drag and l i f t are considered to act. The center of g r a v i t y (G) i s the po i n t through which the weight a c t s . The angle of a t t a c k i s the angle between the d i r e c t i o n of motion and the chord of the f i n . The chord i s the dis t a n c e from the l e a d i n g edge to the t r a i l i n g edge of the f i n . The angle of incidence i s the angle between the l o n g i t u d i n a l a x i s and the chord of the f i n . I f at an angle of a t t a c k of zero degrees there i s no l i f t and the f i s h i s t i l t e d upward the couple RH produces a p o s i t i v e p i t c h i n g moment r a i s i n g the head f u r t h e r and i n c r e a s i n g the angle of a t t a c k . This i s an unstable system. By p l o t t i n g RH against the angle of a t t a c k an accurate measure of s t a b i l i t y i s obtained dRH doc The yawing movements are governed by the median f i n s . I f the yawing moments of a f i s h w ithout these f i n s are p l o t t e d and compared to one wi t h the median f i n s t h e i r f u n c t i o n i s apparent, as i s seen i n f i g u r e s 6 and 7. The system represented by f i g u r e 7 i s s t a b l e up to angles .of attack of 10 . Above t h i s angle the sweep-back of the p e c t o r a l f i n s a i d s d i r e c t i o n a l s t a b i l i t y . The sweep-back 17 F i g * 5. Forces on the f i s h i n the v e r t i c a l plane* 18 i n f a s t -swimming T e l e o s t s i s l a r g e l y r e s p o n s i b l e f o r t h e i r steadiness during a f a s t stop. The p a i r e d f i n s c o n t r o l the e q u i l i b r i u m i n the p i t c h -ing plane. During a stop, when the p e c t o r a l s are exten-ded, there i s a s l i g h t upward l i f t f o r c e because the extended f i n s have a h i g h angle of attack and the angle of incidence has been incre a s e d . This upward f o r c e i s e q u a l i z e d by a downward f o r c e of the p e l v i c f i n s ( f i g . 8 ) . These v e r t i c a l f o r c e s , i n e q u i l i b r i u m , have to be constant-l y changed as the speed decreases. These changes are brought about by r e f l e x c o n t r o l of the angle of i n c i d e n c e . The moment i n the negative p i t c h i n g plane i s e q u a l i z e d by the couple produced by the p e l v i c f i n s . A f i s h w i t h the r e s u l t a n t f o r c e R going through the center of g r a v i t y and w i t h the p e l v i c f i n s removed would f o l l o w a path, as shown i n f i g u r e 9, on stopping. The p e l v i c f i n s can also be used f o r l i m i t e d c o n t r o l i n the r o l l i n g plane and are always extended together. I f one i s removed then exten-s i o n o f the other w i l l cause r o l l i n g toward the u n i n j u r e d s i d e . The median f i n s , and perhaps the p e l v i c s . through b i l g e k e e l a c t i o n ^ are used to maintain e q u i l i b r i u m about the l o n g i t u d i n a l a x i s . Removal of these f i n s causes u n s t e a d i -ness, i n turns and stopping as w e l l as causing yawing. The foregoing d e s c r i p t i o n shows how important the f i n s , are f o r c o n t r o l and. s t a b i l i t y and t h e i r removal could s e r i o u s l y hamper the a b i l i t y of a f i s h to avoid p r e d a t o r s . 19. H -0.2 -0.1 i i -10' 1 5' 10* <* - - 0 - I . - - - 0 . 2 F i g . 6. S t a b i l i t y i n the yawing plane of a f i s h without f i n s ( a f t e r H a r r i s ) . + 0 . H 0.2 + -0 . + -0 .2 F i g . 7 . S t a b i l i t y i n the yawing plane of a f i s h w i t h median f i n s ( A f t e r H a r r i s ) . so F i g . 9. Path of a f i s h without p e l v i c f i n s d e c e l e r a t i n g ( a f t e r H a r r i s ) . 21 H a r r i s (1936) a l s o shows that f i s h do not l e a r n to compen-sate i n a per i o d of two months for the l o s s of t h e i r c l i p p e d f i n s . tt 2S. SUMMARY 1. The A c t i v i t y of f i s h as measured by the c r u i s i n g speed developed by Rogers (Fry and Hart, 1948) i s h i g h l y v a r i a b l e , but t h i s method seems to be a good way of comparing an animal's a c t i v i t y under c o n t r o l l e d c o n d i t i o n s . 2. The removal of two f i n s had no e f f e c t on the c r u i s i n g speed of g o l d f i s h o r cohoe salmon. 3. C o r r e l a t i o n was found between c r u i s i n g speed and l e n g t h and c r u i s i n g speed and weight of g o l d f i s h . 4. The r e g r e s s i o n c o e f f i c i e n t s before and a f t e r c l i p p i n g g o l d f i s h were of the same order. 5. The p o s s i b i l i t y of any increased m o r t a l i t y of marked f i s h caused by d i s t u r b e d s t a b i l i t y during maneuvers was di s c u s s e d . 23. LITERATURE F o e r s t e r , R.E. The r e t u r n from the sea of Sockeye salmon (Qncorhynchua nerka) w i t h s p e c i a l reference to percentage s u r v i v a l , sex p r o p o r t i o n s and progress of m i g r a t i o n . Journ. B i o l . Bd. Con., 4: 26-42, 1936. Fr y , F.E.J, and Hart, J.S. C r u i s i n g speed of g o l d f i s h (Carassius auratus) i n r e l a t i o n to water temperature. Journ. F i s h Res. Bd. Con., 7_ 169-175; 1948. Gray, J . Studies i n animal locomotion. Journ. Exper. B i o l . , 10: 391-400, 1936. - - - - Pseudo-rheotropism i n f i s h e s . Journ. Exper. B i o l . , 14: 95-103, 1937. H a r r i s , J.E. The r o l e of f i n s i n the e q u i l i b r i u m of the swimming f i s h . Journ. Exper. B i o l . , 15: 476-493, 1936. - - - - P a i r e d f i n s i n the T e l e o s t e i . Pap. Tortugas Lab. Carn. I n s t n . , 31: 173-189, 1937. - - - - The r o l e of the f i n s i n e q u i l i b r i u m of the swimming f i s h . Journ. Exper. B i o l . , 15: 32-47, 1938. R i c k e r , W.E. E f f e c t of removal of f i n s upon the growth and s u r v i v a l of spiny-rayed f i s h e s . Journ. W i l d . Mgt., 13: 29-40, 1949. 23 a Snedecar, G.W. S t a t i s t i c a l Methods T h i r d E d i t i o n , 1-4.22, The Iowa State College P r e s s , Ames, Iowa, 1940. Ward, H.B. The m i g r a t i o n and conservation of salmon. 41-59, The Science P r e s s , Lancaster, Penn. 1939. 24 APPENDIX The mean cru i s i n g - s p e e d i n r e v o l u t i o n s per minute f o r each t r i a l , weight and l e n g t h of each f i s h . I . G o l d f i s h . F i s h Number 1, 8.26 gm., 7.1 om. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DBV 1 60.0 1 53.6 2 60.0 2 58.9 3 59.5 3 57.6 4 60.0 4 57.6 5 58.9 5 54*5 6 59.4 6 51.1 7 57.3 7 54.5 8 50.8 8 53.5 9 54.5 9 60.0 10 54.5 10 52.6 F i s h Number 2, i 6.8 gm., 5.6 cm. Be'fore A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DBV 1 50.9 1 45.2 2 69.9 2 57.5 3 68.2 3 53.5 4 77.0 4 50.9 5 71.0 5 51.6 6 46.1 6 41.8 7 50.0- 7 54.0 8 58.9 8 47.5 • 9 55.5 9 52.5 10 57.6 10 48.4 F i s h Number.3, • 4.6 gm., 6.0 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DBV 1 60.0 1 66.6 2 69.9 a 68.1 3 68.1 3 60.0 4 63.9 4 65.1 5 62.5 5 65.1 6 75.0 6 59.5 7 71.5 7 53.5 8 62.5 8 50.0 9 62.5 9 53.5 10 60*0 10 53.5 26. F i s h Number 4, 8.03 gm., 6.5 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g BV . 1 61.2 1 65.4 2 • 60.0 2 65.4 3 60.0 3 61.2 4 61.2 4 61.2 5 58.9. 5 54.5 6 60.0 6 68.2 7 71.5 7 60.0 8 50.0 8 61.2 9 58.9 9 60.0 10 53.6 10 58.9 F i s h Number 5, 11.09 gm., 7.3 em. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DBV 1 49.3 1 61.2 2 65.4 2 63.8 3 62.5 3 75.0 4 60.0 4 66.0 5 57.6 5 50.9 6 50.9 6 52.6 7 62.5 7 60.0 8 55.5 8 65.4 9 55.5 9 61.2 10 61.2 10 53.6 F i s h Number 6, 4.63 gm., 5.6 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DRV 1 49.3 1 50.4 2 55.5 2 56.5 3 51.7 3 52.6 4 52.6 4 53.6 5 53.6 5 60.0 6 57.6 6 50.0 7 61.2 7 60.0 8 58.9 8 52.6 9 50.9 9 50.0 10 58.9 10 53.6 2 7 F i s h Number 7, 7.14 gm., 6.2 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DLV 1 56.5 1 67.5 2 66.0 2 66.6 3 66.6 3 73.2 4 63.8 4 69.9 5 73.2 5 57.1 6 62.5 6 69.9 7 81.0 7 68.2 8 62.5 8 61.2 9 62.5 9 61.2 10 71.5 10 56 * 5 F i s h ] Number 8, 5.93 gm. , 5.4 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DLV 1 65.4 1 54.5 2 60.0 2 52.6 3 61.2 3 52.6 4 60.0 4 52.6 5 57.6 5 53.6 6 61.2 6 53.1 7 55.5 7 54.5 8 55.5 8 51.7 9 53.1 9 50.9 10 52.6 10 54.5 F i s h : Number 9, 5.2 gm., 5.7 cm. Before - A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DLV 1 48.9 1 52.6 2 46.7 2 63.8 3 44.8 3 58.9 4 50.0 4 60.0 5 51.7 5 81.0 6 46.2 6 66.6 7 52.6 7 68.2 8 65.4 8 60.0 9 50.0 9 65.4 10 56.5 10 59.5 28 F i s h : Number 10, 8.6 gm. , 7.4 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DRV 1 82.2 1 77.0 .2 . 83.4 2 81.0 3 81.0 3 86.7 4 83.4- 4 79.0 5 81.0 5 79.0 6 81.0 6 75.0 7 83.4 7 88.2 8 80.0 8 63.8 9 79.0 9 68.2 10 73.2 10 81.0 F i s h Number 11, 5.1 gm. , 5.4 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DLV 1 55.5 1 60.0 2 55.5 2 65.2 3 56.5 3 60.0 4 57.6 4 59.5 5 55.5 5 61.2 6 52.6 6 62.5 . 7 60.0 7 61.2 8 62.5 8 53.1 9 54.5 9 58.9 10 66.6 10 61.2 F i s h Number 12, 4.9 gm. , 5.3 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DRV 1 51.7 1 60.0 2 60.0 2 44.1 3 57.6 3 58.9 4 58.9 4 60.0 5 55.5 5 58.9 6 55.5 6 54.5 7 55.5 7 49.3 8 56.5 8 46.9 9 46.9 9 50.0 10 49.3 10 50.0 29 F i s h Number 13, 6.58 gm.j 6.2 om. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DRV 1 58.9 1 75.0 2 84.5 2 63.8 3 87.0 3 79.0 4 81.0 4 73.2 5 83.4 5 77.0 6 69.9 6 77.0 7 79.0 7 69.9 8 81.0 8 69.9 9 92.5 9 68.2 10 71.5 . 10 68.2 F i s h ] Number 14, 3.4 gm., , 4.4 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g ARV 1 50.9 1 65.4 2 53.1 2 55.5 3 52.6 3 56.0 4 52.2 4 55.5 5 51.7 5 55.5 6 50.0 6 57.6 7 49.3 7 60.0 8 56.5 8 60.0 9 57.6 9 66.6 10 46.9 10 62.5 F i s h Number 15, 5.05 gm, ,, 5.4 cm Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g ARV 1 56.5 1 54.5 2 66.0 2 57.6 3 61.2 3 55.6 4 60.0 4 54.5 5 61.2 5 54.5 6 60.0 6 54.5 7 61.2 7 57.6 8 56.5 8 56.5 9 54.5 9 57.6 10 60.0 10 54*5 30 Fish Number 16, 2 gm., 4.2 cm. Before After T r i a l Clipping T r i a l Clipping ARV 1 35.5 1 40.0 2 36.2 2 40.0 3 36.6 3 39.0 4 36.2 4 38*4 5 35.5 5 39.0 6 35.3 6 38.5 7 36.2 7 37.3 8 37.3 8 37.3 9 35.7 9 36*6 10 35.7 10 35.3 Fish Number 17, 5.45 gm. , 5.8 cm. in Before After T r i a l Clipping T r i a l Clipping ARV 1 75.5 1 88.2 2 96.7 2 79.0 3 85.6 3 74,1 4 81.0 4 77.0 5 83.4 5 60*0 6 83.4 6 63.8 7 71.5 7 66.6 8 73.2 8 61.2 9 63.8 9 61.2 10 77.0 10 75.0 Fish ] Number 18, 2,18 gm* , 4.2 cm. Before After T r i a l Clipping T r i a l Clipping BV 1 48.4 1 49.3 2 46.9 2 50.9 3 48.4 3 50.9 4 48.0 4 48.8 5 49.6 5 50.0 6 48.0 6 51.7 7 51.7 7 54.5 8 50.9 8 48.4 9 46.2 9 49.3 10 46.9 10 54.5 31 Fish Number 19, 7.71 gm., 6.4 cm. Before After Trial Clipping Trial Clipping BV 1 60.0 1 50.0 2 60.0 2 48.3 3 57.2 3 51.7 4 61.7 4 53.5 5 72.2 5 53.1 6 58.9 6 53.6 7 60.0 7 66.6 8 66.6 8 65.4 9 62.5 9 68.2 10 62.5 10 73.2 Fish Number 20, 7.86 gm., 5.8 cm. Before After Trial Clipping Trial Clipping BV 1 51.7 1 55.5 a 48.4 2 60.0 3 50.0 3 60.0 4 50.0 4 60.0 5 50.0 5 57.1 6 51.7 6 83.4 7 56.5 7 85.6 8 75.0 8 81.0 9 60.0 9 83.4 10 61.2 10 .88.2 Fish Number 21, 13.4 gm., 7.3 cm. Before After •ial Clipping Trial Clipping ARP 1 65.4 1 71.5 2 63.8 2 75.0 3 66.6 3 73.2;.; 4 76.0 4 71.5 5 68.2 5 73.2 6 69.9 6 71.5 7 71.5 7 69.9 8 79.0 8 61.2 9 73 k2 9 63.8 10 79.0 10 58.9 32 F i s h Number 22, 11.9 gm., 7.4 cm. Before T r i a l C l i p p i n g T r i a l C o n t r o l 1 65.4 2 81.0 3 94.0 4 85.6 5 81.0 6 75.0 7 73.2 8 63.8 9 60.0 10 63.8 1 58.9 2 60.0 3 94.0 4 66.6 5 58.9 6 69.9 7 65.4 8 63.8 9 62.5 10 65.4 F i s h Number 23, 11.8 gm., 7.4 cm. Before T r i a l C l i p p i n g T r i a l C o n t r o l 1 55.5 1 73.2 2 55.5 2 75.0 3 55.5 3 65.4 4 65.4 4 68.2 5 61.2 5 68.2 6 83.4 6 66.6 7 71.5 7 68.2 8 82.2 8 72.2 9 66.6 9 63.8 10 77.0 10 65.4 F i s h Number 24, 12.2 gm., 7.2 cm. Before T r i a l C l i p p i n g T r i a l C o n t r o l 1 48.4 2 65.4 3 54.5 4 57.6 5 66.6 6 63.8 7 62.5 8 69.0 9 69.0 10 69.0 1 69.9 2 68.2 3 75.0 4 71.5 5 63.8 6 100.0 7 66.6 8 60.0 9 83.4 10 92.5 33 F i s h Number 25, Before T r i a l C l i p p i n g 1 57.6 2 56.5 3 63.8 4 53.6 5 55.0 6 63.8 7 63*8 8 56.5 9 53.6 10 56.5 F i s h Number 26, Before T r i a l C l i p p i n g 1 71.5 2 69.9 3 80.0 4 77.0 5 71.5 6 75.0 7 73.2 8 71.5 9 69.9 10 71.5 F i s h Number 27, Before T r i a l C l i p p i n g 1 62.5 2 61.2 3 54.5 4 68.2 5 54.5 . 6 57.6 7 60.6 8 54.5 9 62.5 10 60.0 11.5 gm., 7.6 cm. T r i a l C o n t r o l 1 51.7 2 55.5 3 60.0 4 61.2 5 61.2 6 66.6 7 65.4 8 55.5 9 56.5 10 58.1 6.3 gm., 6.2 cm. A f t e r T r i a l C l i p p i n g ARP 1 83.4 2 83.4 3 81.0 4 64.5 5 75.0 6 73.2 7 79.0 8 63.0 9 77.0 10 75.0 13.8 gm., 8.0 cm. A f t e r T r i a l C l i p p i n g ARP 1 63.8 2 65.4 3 61.2 4 66.6 5 63.8 6 63.8 7 63.8 8 61.2 9 63.8 10 60.0 34 F i s h Number 28* 15.6 gm., 7.8 cm. Before T r i a l C l i p p i n g T r i a l C o n t r o l 1 61.2 1 90.0 2 55.5 2 88.2 3 55.5 3 96.7 4 54.5 4 65.4 5 69.9 5 72.2 6 73.2 6 73.2 7 71.5 7 91.0 8 63.8 8 73.3 9 56.5 9 79.0 10 73.2 10 71.5 F i s h Number 29, 13*8 gm*, 6.9 cm. Before T r i a l C l i p p i n g 1 52.2 2. 52.6 3 52.2 4 57.6 5 57,6 6 58.9 7 58.9 8 60.0 9 60.0 10 60.0 T r i a l C o n t r o l 1 60.0 2 61.2 3 65.4 4 65*4 5 60.0 6 68.2 7 68.2 8 65.4 9 66.6 10 65.4 F i s h Number 30* 13.8 gm., 7.7 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g ARP 1 55.5 1 63.8 2 54.5 2 63.8 3 57.6 3 70.6 4 73.2 4 63.8 5 68.2 5 63.8 6 73.2 6 63.8 7 77.0 7 62.5 8 75.0 8 62.5 9 75.0 9 64.5 10 75.0 10 63.8 35 II. Cohoe Fry. Fi s h Number 31, 8.75 gm., 8.6 cm. Before T r i a l Clipping T r i a l Control 1 60.0 1 69.9 2 60.0 2 ' 68.2^ 3 69.9 3 69.9 4 77.0 4 68.2 5 70.6 5 69.9 6 71.5 6 69.9 7 69.9 7 68.2 8 79.0 8 69.9 9 60.0 9 71.5 10 75.0 10 69.9 F i s h Number 32, 71.15 gm., 8.3 i Before T r i a l Clipp ing T r i a l Control 1 75.0 1 48.4 2 73.2 2 48*4 3 37.0 3 49.3 4 46.2 4 ' 48.4 5 46.2 5 49.3 6 46.9 6 49.3 7 50.0 7 49.3 8 46.9 8 50.0 9 50.0 9 50.9 10 50.9 10 48.4 F i s h Number 33, 5.36 gm., 7.3 cm. '.'„• Before After T r i a l Clipping T r i a l Clipping BV 1 63.8 1 66.6 2 61.2 2 65.4 3 61.2 3 63.8 4 66.6 4 63.8 5 68.2 5 63.0 6 66.6 6 63.8 7 70.6 7 65.4 8 68.2 8 66.6 9 68.2 9 63.0 10 68.2 10 63.0 36 F i s h Number 34, 9.75 gm., 9.2 cm. Before' A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g BV 1 68.2 1 60.0 2 66.6 2 60.0 3 66.6 3 60.0 4 65.4 4 60.0 5 64.5 5 60.0 6 66.6 6 60.0 7 65.4 7 61.2 8 60.0 8 56.5 9 66.6 9 58.9 10 66.6 10 57.6 F i s h Number 35, 7.3 gm. , 8.2 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g . DRV 1 37.5 1 48.4 2 S5.6 2 50.9 3 35.8 3 50.4 4 46.2 4 52.2 5 44.8 5 51.7 6 44.8 6 50.9 7 46.9 7 50.9 8 37.5 8 52.6 9 48.4 9 50.9 10 46.2 • 10 52.6 F i s h Number 36, 8.5 gm. , 7.7 cm. Before A f t e r T r i a l C l i p p i n g T r i a l C l i p p i n g DRV 1 61.2 1 60.0 2 50.9 2 61.2 3 50.0 3 61.2 4 65.4 4 66.6 5 60.0 5 66.6 6 65.4 6 66.6 7 60.0 7 66.6 8 60.0 8 60.0 9 68.2 9 60.0 10 73.2 10 60.0 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
https://iiif.library.ubc.ca/presentation/dsp.831.1-0107011/manifest

Comment

Related Items