Science, Faculty of
Zoology, Department of
DSpace
UBCV
Topping, Milton Stanlee
Master of Science - MSc
University of British Columbia
Oxygen consumption of the copepodid V stages of Calanas plumchras was studied with respect to environmental and endogenous factors using standard closed chamber technique and Warburg respirometry. Specimens were collected from San Juan Channel, Washington and Indian Arm, British Columbia. Rate of oxygen consumption of C, plumchrus (1) is significantly decreased by population densities of 5 or more copepods / ml, (2) demonstrates no regular endogenous change, (3) is not significantly affected by presence or absence of light, (4) is directly proportional to temperature (being variously linear and non-linear in response) throughout the range of 5-20° C, (5) does not vary significantly over a salinity range of 20-35 ppt (but during May 1965 increased at 10 ppt and decreased at 45 ppt), (6) decreases to a minimum below an ambient oxygen concentration of 3 co 0₂ per liter and (7) is not significantly affected by increased hydrostatic pressure corresponding to a depth of about 400 m. Response to a range of temperatures, in particular, indicates that oxygen measurements taken from different collections are statistically different and therefore not directly comparable. In general, the data presented are consistent with McLaren's theory of energy utilization and vertical migration, although temperature does not always appear to be the most significant factor. Interaction and variation of environmental factors may explain some of the complexity of vertical migration.
A STUDY OF OXYGEN OOHSUMPTIOH IH Oalanas p l a m e h r a B MAEUZAWA 1921 AND IMPLICATIONS OK VERTICAL MIGHATION MILTON STANLEE TOPPING B.A., Unive r s i t y of Kansas, 1962 A Thesis submitted i n P a r t i a l Fulfilment of the Requirements f o r the Degree of Master of Science i n the Department of Zoology We accept t h i s thesis as conforming to the required, standard The Un i v e r s i t y o f B r i t i s h Columbia A p r i l , 1966 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make i t freely available for reference and study. I further agree that per-mission for extensive copying of this thesis for scholarly purposes may be granted by the Head of my Department or by his representativeso It is understood that copying or publi-cation of this thesis for financial gain shall not be allowed without my written permission. Department of ~/cZ 6± The University of British Columbia,. Vancouver 8, Canada. Date Q.& ADAJJ I q&G, i i Abstract Oxygen consumption of the eopepodid Y stages of Oalanas plumohras was studied with respect to environmental and endogenous factors using standard closed chamber technique and Warburg respirometry. Specimens were collected from San Juan Channel, Washington and Indian Arm, B r i t i s h Columbia. Rate of oxygen consumption of C, plumchrus (1) i s sig-nificantly decreased by population densities of 5 or more copepods / ml, (2) demonstrates no regular endogenous change, (3) i s not significantly affected by presence or absence of light, (4) i s directly proportional to temperature (being variously linear and non-linear in response) throughout the range of 5^20° 0, (5) does not vary significantly over a sal i n i t y range of 20-35 ppt (but during May 1965 increased at 10 ppt and deoreased at 45 ppt), (6) decreases to a minimum below an ambient oxygen concentration of 3 co 0% per l i t e r and (7) i s not significantly affected by increased hydrostatic pressure corresponding to a depth of about 400 m, Response to a range of temperatures, i n particular, indicates that oxygen measurements taken from different collections are s t a t i s t i c a l l y different and therefore not directly comparable. In general, the data presented are consistent with McLaren's theory of energy u t i l i z a t i o n and vertical migration, although temperature does not always appear to be the most significant factor. Interaction and variation of environmental factors may explain some of the complexity of vertical migra-tion. i i i Table of Contents p a g e Abstract • • ••• i i L i s t of Tables i v L i s t of Figures v Acknowledgments • v i I. Introduction • 1 I I , Materials and Methods 3 A. Crowding 6 B. Bhythmicity 6 C. Light • 7 D. Temperature • 7 E. S a l i n i t y • 7 P. Oxygen concentration • 7 Gr. Pressure •• 8 I H . Besults ..10 A* Crowding 10 B. Bhythmicity 10 C. Light 13 D . Temperature 13 E. S a l i n i t y 16 F. Oxygen concentration • 18 0. Pressure • 20 IV. Disoassion 22 A. Considerations of technique •••• 22~ B. E f f e c t of factors 24 C. Oxygen u t i l i z a t i o n i n nature 32 V* Summary...... • 37 VI. L i t e r a t u r e Cited 39 VII. Appendioes 43 Appendix I. Crowding • 43 Appendix I I . Bhythmicity 44 Appendix I I I . Light and temperature 46 Appendix IV. Temperature ••••••••••••• •• 47 Appendix V. S a l i n i t y 48 Appendix VI. Oxygen concentration ••••••••••••• 49 Appendix VII. Pressure ••••• 50 iv List of Tables page Table I. Length variation with season •••••••••••••• 6 Table I I * Probability of random odoarrenoe of rises and f a l l s i n rhythmicity data •••••• 13 Table III* Adjusted means of temperature data ••• 16 Table 17* Minimal lethal concentration of oxygen ....18 Table V. Summary of seasonal comparison of water properties of San Juan Channel, Wash, and Indian Arm, B.C. ••............•*.••• 34 L i s t of Figures page Figure 1. Pressure apparatus •••• 9 Figure £• Bate of oxygen consumption vs orow&ing ••• 11 Figure 3. B i e l oxygen consumption during summer with continuous exposure to l i g h t ••••••• 11 Figure 4* D i e l oxygen consumption during winter with exposure to various l i g h t regimes •• 12 Figure C5. Bate of oxygen consumption i n l i g h t and dark vs temperature • • •••• 14 Figure 6. Bate of oxygen consumption vs temperature, 15 Figure 7* Bate of oxygen consumption vs s a l i n i t y ••• 17 Figure 8. Bate of oxygen consumption vs oxygen concentration • ••••••• •••• 19 Figure 9* Bate o f oxygen consumption vs pressure £1 v i AGZHOWIEDGMEKTS T h e a u t h o r g r a t e f u l l y a c k n o w l e d g e s f a c i l i t i e s p r o v i d e d b y t h e D e p a r t m e n t o f Z o o l o g y , U n i v e r s i t y o f B r i t i s h C o l u m b i a . S p e c i a l a c k n o w l e d g m e n t i s g i v e n t o B r , R o b e r t L. F e m a l d , B i r e e t o r , f o r o o u r t e s y e x t e n d e d a n d f a c i l i t i e s p r o v i d e d b y F r i d a y H a r b o r l a b o r a t o r i e s , U n i v e r s i t y o f W a s h i n g t o n . S h i p t i m e w a s p r o v i d e d b y F r i d a y H a r b o r l a b o r a t o r i e s , a n d t h e I n s t i t u t e o f F i s h e r i e s a n d I n s t i t u t e o f O c e a n o g r a p h y , U n i v e r s i t y o f B r i t i s h C o l u m b i a . A p p r e c i a t i o n i s e x p r e s s e d t o D r . I . E . E f f o r d j D r . W . S . H o a r , B r . D . J . E a n d a l l a n d B r . G . G . E . S o u d d e r f o r t h e i r c r i t i c a l r e a d i n g o f t h e m a n u -s c r i p t . D i s c u s s i o n w i t h a n d e n c o u r a g e m e n t g i v e n b y D r . G . G . E . S o u d d e r a n d D r , A . B . A c t o n i s e s p e c i a l l y a p p r e c i a t e d . l o a n o f e q u i p m e n t a n d v a r i o u s h e l p f r o m B r , A . B . A o t o n , D r . C . V , F i n n e g a n , D r , G . G . E . S c u d d e r a n d M r , H . H . W e b b e r i s a l s o a c k n o w l e d g e d . R e s e a r c h r e p o r t e d w a s u n d e r t a k e n w h i l e t h e a u t h o r r e c e i v e d f i n a n c i a l s u p p o r t f r o m F r i d a y H a r b o r L a b o r a t o r i e s , U n i v e r s i t y o f W a s h i n g t o n ( N a t i o n a l S c i e n c e F o u n d a t i o n Summer F e l l o w s h i p ) a n d t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a ( P r e s i d e n t ' s F u n d g r a n t t o B r , I . E . E f f o r d ) . I* Introduction Crustaceans are the predominant component of marine zoo-plankton, both i n numbers and i n species, and the calanoid copepods comprise the largest portion of t h i s group (Raymont, 1963)* Therefore, the r o l e of marine calanoid copepods i n energy u t i l i z a t i o n i n the ocean i s v i t a l to our understanding of the marine ecosystem. Most studies of oxygen consumption of various marine species concern the i n t e r p r e t a t i o n of food requirements and feeding r e l a t i o n s h i p s , and involve the e f f e c t o f one or at most two environmental f a c t o r s . Only one reported study i s concerned with an extensive survey o f oxygen consumption with respect to environmental faetors (Marshall, K i c h o l l s and Orr, 1935), In addition, most of the information available i s r e s t r i c t e d to species occurring i n the northern A t l a n t i c Ocean, Hence, i t i s desirable to obtain more complete knowledge of oxygen consumption of various species. In view o f a hypothesis proposed by McLaren (1963), the general problem of energy u t i l i z a t i o n i n zooplankton with reference to t h e i r v e r t i c a l p o s i t i o n i n a water body i s of i n t e r e s t . According to t h i s hypothesis, zooplankton lower i n a water body should use l e s s oxygen. I f temperature i s the only factor considered, zooplankton i n most oceanic situations would decrease energy u t i l i z a t i o n with increase i n depth. However, at l e a s t two other environmental factors change i n a predictable manner as a function of depth and consequently are of at l e a s t t h e o r e t i c a l i n t e r e s t , v i z . . l i g h t and pressure. 2 In p a r t i c u l a r * the only published report o f the effect of hydrostatic pressure on the oxygen consumption of a marine zooplanktor indicates that oxygen consumption Increases with increase i n pressure (Hapora, 1964). I f Napora's observation represents a general response of zooplankton, then one would not automatically predict a decrease i n energy u t i l i z a t i o n with increase i n depth. Moreover, i n coastal waters other water properties may vary considerably (e.g., s a l i n i t y and oxygen concentration). Generalization of the ef f e c t of most environmental factors on oxygen consumption of zooplankton i s impossible and therefore, i n order to conclude that indeed l e s s energy i s used when deeper i n a water body, several factors must be studied. The purpose of t h i s study i s to investigate McLaren's hypothesis as i t r e l a t e s to energy u t i l i z a t i o n of a marine oalanoid oopepod by analysis of endogenous change i n rate of oxygen consumption and change i n rate of oxygen consumption i n response to environmental factors, and to contribute to the general knowledge of oxygen consumption i n copepods. 3 II* Materials and Methods Copepodld V stages of Oalanas plamehras Marakawa 1921 were used throughout the study* C* plumohrus ocours i n the northern Pacific Ocean (Brodsky, 1950; Mori, 1937)* In the Strait of Georgia and neighboring waters the species i s most abundant from February to May, but may be taken from deep waters throughout most of the year* Confusion exists on the status of G* plumohrus as a species distinot from Oalanas tonsas Brady* Brodsky (1957:49) and Zenkevitoh (1963) consider G* plumohrus to be C* tonsus; however, Tanaka (1956) states emphatically that both are distinct species* In view of this confusion, comparative data which was taken from the l i t e r a -ture and which concerns C* tonans i s used ln the following only when C* plumohrus was d e a r l y the form (species) to which reference was made* Experiments reported herein were conducted at Friday Harbor Laboratories, University of Washington (SELL) and at the Department of Zoology, University of B r i t i s h Columbia (UBC). Copepods used at the respective l o c a l i t i e s were collected from San Juan Channel, Washington (48° 44 1 H l a t , 123° 2 1 W long) and Indian Arm, B r i t i s h Columbia (49° 21» H lat» 122° 54» W long)* Specimens were collected by means of a ooarse meter net using oblique and vertical tows from depths of 60-150 m* Water used i n experiments at FHL was taken from the running sea water system and water used at UBC was collected with, a Tan Bom bottle from a depth of 150 m at the l o c a l i t y where copepods were collected* After collection, copepods used for 4 experiments at FKL were dilated and returned to the laboratory for separation (a t r i p of 20 min), while copepods used at T3BC were separated on ship prior to return* Material was main-tained i n aquaria containing onfiltered sea water at 10°-12® 0 for periods varying from one day to two weeks subsequent to collection* laboratory photoperiod to which copepods were ex-posed during this period, was not controlled* Ho copepods were used for experimentation u n t i l 24 hrs after collection* Closed chambers of 10, 35, and 50 ml and a Warburg respirometer were used to determine rate of oxygen consumption* Prooedure used i n closed chamber experiments i s described by Conover (1956) and techniques used i n the Warburg studies are described by TJmbreit et a l i (1959)* Copepods were acclimated to the test chambers at 10°-12° G for at least 12 hrs prior to test i n a l l except the 10 ml chambers* Copepods tested in the 10 ml chambers were used immediately after introduction into the chambers* A l l rates of oxygen consumption were de* termined acutely and except when the effect of light was studied,, tests were conducted in constant darkness* Water used in the experiments was f i l t e r e d using 0.45 u HA m i l l i -pore f i l t e r s * Antibiotics were not used i n the experiments* In closed chamber experiments, concentration of oxygen was determined by t i t r a t i o n using the unmodified Winkler technique and by the technique described by Pamatmat (1965) using a Beckman Oxygen Analyzer (Model 777)* Copepods which were used i n the experiments were col* looted during different seasons (and i n one set of experiments 5 from a d i f f e r e n t l o c a l i t y ) and they vari e d s i g n i f i c a n t l y (P < 0.01) i n eephalothorax length (Table I ) . Rates of oxygen oonsamption determined daring these seasons were thus cor-rected and expressed f o r a standard oephalothorax length of three millimeters. Corrected and uncorrected values of rates of oxygen consumption are given i n Appendices IVWTI. Bata f o r the e f f e c t of crowding, rhythmioity and photoperiod on rate of oxygen consumption were not corrected since either the re«-sponses being studied were not a function of quantitative differences i n rates o f oxygen consumption, or beoause data being oompared were c o l l e c t e d during the same season and from the same general l o c a l i t y . Rates of oxygen consumption of r e p l i c a t e experiments within the same season were not cor-rected f o r size v a r i a t i o n . Although rates of oxygen consumption were determined with respect to d i f f e r i n g l o c a l i t i e s and seasons, attention i s directed p a r t i c u l a r l y , f i r s t , to the general character of response o f oxygen consumption to the various environmental factors and second, to the r e l a t i v e importance of each of these f a c t o r s . S t a t i s t i c a l analyses used are described by PreuncL, livermore, and M i l l e r (1960) and Snedeeor (1956). When analysis of variance was used to analyze more than one mean, Sig n i f i c a n t differences were determined by Duncan*s new multiple range comparison (ground et al.» I960)* Variances of means oompared by analysis of variance and by Student's " t n t e s t were oompared by ratio:: of maximum varlanoe to 6 minimom variance (Biometrika Tables for Statielans, pp. 60-61 and 179). In this study. P <0#01 was used as the level of significance unless otherwise stated. In addition to general methods outlined above several speoifio methods were employed. A. Crowding. The effect of crowding on rate of oxygen consumption was determined by analysis of rhythmicity data in which varying numbers of copepods were studied i n a constant volume of water. B. Rhythmicity. Hourly rates of oxygen consumption under conditions of constant exposure to light and dark, and alternating exposure to dark and light were determined i n a manner similar to that described by Raymont and Gauld (1951) by means of a Warburg respirometer for periods exdeeding 30 hrs. Presumably an "endogenous" rhythm i n oxygen consumption Table I. Variation i n length of oephalothorax of copepodid Y stages of C. plumohrus used i n the oxygen consumption studies. Comparison of means by Duncan's new multiple range comparison indicates a l l means are significantly different from eaoh other. Source Date Sample Size Mean Length (mm) FHL June 1964 36 3.24 FED May 1965 101 1*52 UBC November 1965 34 3*65 should appear i n constant conditions and an "exogenous" rhythm i n oxygen consumption should be induoed by exposure to alternating dark and light (assuming light i s a primary 7 c o n t r o l l i n g f a c t o r ) . T h e d a r k - l i g h t r e g i m e c o r r e s p o n d e d t o t h e n o r m a l p h o t o p e r i o d c y c l e . F l a s k s c o n t a i n e d a i r a s t h e g a s a n d w e r e s h a k e n a t t h e r a t e o f 120 t i m e s / m i n . T e s t s c o n d u c t e d d u r i n g 1964 ( F H L ) w e r e r u n a t 10° 0 a n d v a r y i n g n u m b e r s o f c o p e p o d s w e r e u s e d p e r f l a s k , w h e r e a s d u r i n g 1965 (UBC) t e s t s w e r e r u n a t 13° C a n d c o n s t a n t n u m b e r s o f c o p e p o d s w e r e t e s t e d . C . L i g h t . T h e r a t e o f o x y g e n c o n s u m p t i o n o f c o p e p o d s i n t h e l i g h t a n d d a r k o v e r a t e m p e r a t u r e r a n g e o f 5°-20° C w a s d e t e r m i n e d w i t h a W a r b u r g r e s p i r o m e t e r . The same c o p e p o d s w e r e u s e d a t a l l t e m p e r a t u r e s . A c u t e o x y g e n c o n s u m p t i o n w a s m e a s u r e d f o r a p e r i o d o f a b o u t s i x h r s s u b s e q u e n t t o o n e h r a o c l i m a t i o n t o t e m p e r a t u r e c h a n g e . T h e e x p e r i m e n t r e p o r t e d i n S e c t i o n I I B w a s a l s o a n a l y z e d t o d e s c r i b e a n y e f f e c t o f c o n s t a n t l i g h t a s o p p o s e d t o d a r k a n d t h e e f f e c t o f c h a n g e s f r o m d a r k t o l i g h t . D. T e m p e r a t u r e . S t a n d a r d m e t h o d s d e s c r i b e d b y C o n o v e r (1956) w e r e u s e d t o d e t e r m i n e t h e e f f e c t o f t e m p e r a t u r e . E . S a l i n i t y . W a t e r o f s a l i n i t y l o w e r t h a n a m b i e n t s a l i n i t y w a s p r e p a r e d b y d i l u t i n g w i t h g l a s s d i s t i l l e d w a t e r a n d w a t e r o f h i g h e r s a l i n i t y w a s p r e p a r e d b y b o i l i n g t h e s e a w a t e r a n d r e a d j u s t i n g t o t h e d e s i r e d s a l i n i t y w i t h g l a s s d i s t i l l e d w a t e r . F . O x y g e n c o n c e n t r a t i o n . O x y g e n c o n c e n t r a t i o n s w e r e p r e p a r e d b y b u b b l i n g 99$ n i t r o g e n g a s o r b y r e p e a t e d f i l t e r i n g w i t h a m i l l i p o r e a p p a r a t u s . O x y g e n l e v e l s w e r e d e t e r m i n e d b y t i t r a t i o n o r b y a n o x y g e n e l e c t r o d e a n d r e a d j u s t e d t o g r e a t e r 8 quantities as desired by shaking or bubbling with a i r . Minimum oxygen concentrations t o l e r a b l e were estimated from t e s t s conducted during 1965 i n which copepods reduced the oxygen to a l e t h a l concentration* G* Pressure* The e f f e c t of pressure was studied by placing 5-10 copepods i n a 10 ml p l a s t i c syringe* Water i n the syringe was slowly extruded leaving a small volume with the copepods, the plunger was removed* a siphon apparatus inserted and the syringe f i l l e d and overflowed* The plunger was in s e r t e d excluding a i r bubbles and the volume adjusted to 10 ml* The needle was plugged with s i l i c o n grease t o stop oxygen exchange with the exterior media* Replicates and con* t r o l s were placed i n a pressure chamber which was pre-cooled to the desired temperature* Pressure was adjusted and the chamber placed i n a r e f r i g e r a t o r * At the end of the t e s t period, pressure was released quickly, the syringes removed and concentration of oxygen i n the t e s t and control syringes determined by means of an oxygen electrode* Oxygen was not released from solu t i o n when the pressure was lowered* Tests at d i f f e r e n t pressures were run f o r approximately the same length of time and under constant darkness* The pressure apparatus i s shown i n Figure 1* Three large b o l t s hold the ends against the pipe and a seal i s of--fected by "0" rings* A pressure gauge was tapped into one end and a screw top sealed by an "0" r i n g i s contained i n the other end* The screw top contains a screw«*piston pump whioh created the pressure* 9 A Pressure apparatus wi th .an enlarged view of the cap (AV. containing the screw-piston pump (B). The control and test chambers are introduced into the pressure chamber (C) when the cap is removed. The chamber is filled with water, rhe cap is screwed into place excluding a i r , and pressure is adjusted by means of the pump. Pressure is read from the gauge (D) and is maintained by the O ring seals (€) . 10 I I I * Results A* Crowding, Analysis o f variance of the data c o l l e c t e d (Figure 2 and Appendix I) Indicates that rate of oxygen oon-» sumption d i f f e r s s i g n i f i c a n t l y with respect to population density and Duncan's new multiple range comparison Indicates that rate of oxygen consumption of copepods tested at the density of f i v e copepods per ml i s s i g n i f i c a n t l y lower than rates determined for copepods tested at l e s s e r densities* B. Bhythmioity* D i e l changes l n rate of oxygen consump-t i o n were determined for copepods acclimatized to summer and winter conditions and tested i n various l i g h t regimes (Figure 3 and 4 and Appendix I I ) * The sets of data were analyzed by analysis of variance to determine the presence of s i g n i f i c a n t temporal changes i n rate of oxygen consumption and those sets of data with s i g n i f i c a n t changes were both transformed and analyzed by the method described by Enrlght (1965) which i s designed to emphasize regular trends and to minimize the e f f e c t of random fl u c t u a t i o n s i n s e r i a l data* In addition* each of the sets of data were analyzed by the method described by Swed and Eisenhart (1943) to determine i f r i s e s and f a l l s i n rates of oxygen consumption occur randomly or i n a non-random pattern* S i g n i f i c a n t changes i n rates of oxygen consumption were observed i n curves A, B, and E* Ho regular trend could be associated with the changes observed i n curves A and B, but the changes i n rates i n curve E may be at least p a r t i a l l y associated with the change from dark to l i g h t * Ho s i g n i f i c a n t 11 -o O Q_ <L> Q. o U T3 0) CM o •o 0-5 FIGURE 2. m 5 4 3 2 , Copepods / Rate of oxygen consumption ( ± one standard errorywith respect to crowding. Copepods tested were taken from a single collection during June 1964 (FHLV O o a . <v Q. O U at CM o •o 0-5 4 8 12 Time (hrs) 16 20 24 FIGURE 3 . Diel changes in rate of oxygen consumtion of two collections of copepods tested under constant exposure to light during June 1964 (FHL). Normal photoperiodic cycle is shown on the abscissa. 2-0 o Q_ <u Cx. o o T3 o •o 0 - 5 2 0 24 4 8 12 16 2 0 24 Time (hrs) FIGURE 4 . Diel changes in rate of oxygen consumption of copepods under exposure to constant light (curveC\ constant dark (curve D), and alternating light-dark (curve E). C o p e p o d s tested were taken from a single collec-tion during November 1965 (UBCV Normal photoperiodic cycle is shown on the absrissa. 13 temporal changes i n rate of oxygen consumption were observed i n curves C and D. Further, the r i s e and f a l l i n rate of oxygen consumption does not occur i n any s i g n i f i c a n t pattern (Table I I ) • Therefore, no rhythmic change i n rate of oxygen consumption was concluded to be present. Table I I . P r o b a b i l i t y of random grouping of r i s e and f a l l i n rate o f oxygen consumption with respect to time i n curves A-E i n Figures 3 and 4. Curve P r o b a b i l i t y A 0.68 B 0*99 C 0.96 D 0.73 E 0.97 C. Light. Analysis of variance indicates no s i g n i f i c a n t difference between rates of oxygen consumption of copepods tested i n the presence or absenoe of l i g h t either with respeot to temperature (Figure 5 and Appendix III) or with respect to d i e l changes (curves C and D, Figure 4 ) . However* a s i g n i f i -cant increase i n rate of oxygen consumption was observed when copepods were switched suddenly from dark to l i g h t (curve E, Figure 4 ) . Subsequent means (1.30 and 1.25) were also found to d i f f e r s i g n i f i c a n t l y from the remainder o f the curve. D» Temperature. Four examples of rate of oxygen con-sumption as a function of temperature are given (Figure 6 and Appendix IV). Bate of oxygen consumption increased with LIGHT D A R K 5 10 15 2 0 Temperature (° c) Rate of oxygen consumption (±one standard error) with respect exposure to light and dark at fo temperatures. Copepods tested were taken from a single collection during June 1965 (UBC) . o o_ CL. O U •o 0-8 0-6 o a, CM 0-2 O -O-- A - — • v-A JUNE 1964 B . JUNE 1964 C MAY 1965 D NOV 1965 FHL FHL FHL UBC IO 15 Temperature ( ° C ) FIGURE 6. Rate of oxyqen consumption ( ± one standard error) with respect to temperature, line were collected from separate collections of copepods. 2( D a t a for eacl 16 temperature when tested over a range of 5^20° 0 . Data for line C were oolleoted from a population s t a t i s t i c a l l y d i f -ferent from that which lines A, B, and D were collected (.i*e*, the sample variance of data for line C differed from the variances of data for lines A, B, and D by a ratio with P<0.01) and l i k e l y were from a different population* Since the sample variance of line C could not be attributed to sampling error, the line i s compared no further s t a t i s t i c a l l y * Analysis of co-variance of lines A, B,and D indicate the regression coefficients of the lines do not d i f f e r significant** l y , but elevations of the lines are significantly different* Duncan's new multiple range comparison indicates each of the means when adjusted (Table III) di f f e r significantly from each other* Table III* Adjusted means of lines A, B, and D, Figure 6* Line Mean Adjusted Means A 0.67 0.69 B 0*62 0.64 C 0.30 0.24 Mortality occurred i n tests of rate of oxygen consump-tion at 20° C during May 1965 and at 18 Q C during Hovember 1965* indicating the upper lethal temperature was approached* No mortality was observed at 20° G during June 1964* E * Salinity* Analysis of variance of change ln rate of oxygen consumption with respect to s a l i n i t y (Figure 7 and 1-5 O Q_ O) OL O O •o CM o 0 - 5 O -•tW-!">!" JULY 1964 MAY 1965 IO 15 20 25 3 0 35 Salinity (parts per thousand) 4 0 45 FIGURE 7- Rate of oxygen consumption ( ± one standard error) with respect to salinity of two collections of copepods (FHL). 18 Appendix V) indicates no s i g n i f i c a n t difference i n 1964 data, bat indicates s i g n i f i c a n t v a r i a t i o n i n the 1965 data* Duncan's new multiple range comparison indicates rate i s s i g n i f i c a n t l y higher at 10 parts per thousand (ppt) and s i g n i f i c a n t l y lower at 45 ppt daring 1965. Two-way analysis of variance o f rates tested at 20, 25, 30, and 35 ppt daring 1964 and 1965 indicates no s i g n i f i c a n t difference with s a l i n i t y or time. Wm Oxygen concentration. S i g n i f i c a n t change i n rate o f oxygen consumption with respect to oxygen concentration and temperature was not observed during May 1965, but was observed at 3° G and 18° G during lovember 1965 (Mgure 8 and Appendix Y I ) . At both temperatures during November 1965* rate of oxygen consumption was r e s t r i c t e d by concentrations o f oxygen l e s s than approximately 3 co oxygen per l i t e r . Minimal l e t h a l oxygen concentrations at three temperatures were determined during November 1965 (Table IV). Lethal minimum oxygen concentrations did not d i f f e r with temperature. Table IV. Minimal oxygen concentrations (oo Og/l) t o l e r a b l e at three temperatures f o r copepods taken from Indian Arm, B.C. 12° G 18° d 0.80 0.70 0.80 0*70 0.65 1.22 0.85 0.85 0*90 1.00 0.87 Mean 0.75 0.84 0.89 19 2 3 4 5 6 Oxygen Concentration (cc O2 / l i t e r ) FIGURE 8- Rate of oxygen consumption (± one standard error) with respect to oxygen concentration and temperature. Copepods tested at 5 , 10°, 20°C.were taken from a single collection during May 1965 (FHL) and copepods tested at 3°. 12 . and 18° C were taken from a single collection during November 1965 (UBC) . so G. Pressare. Hate of oxygen consumption was not s i g n i * f i c a n t l y ohanged by pressures equivalent to a depth of 400 m at 10° or 12° 0 (Figure 9 and Appendix V I I ) . Further, the data were not l i n e a r l y correlated at 10° C and the proba-b i l i t y of l i n e a r c o r r e l a t i o n at 12° C was P<0.05 (shown by a dashed l i n e i n Figure 9). However, i n a l l experiments rate of oxygen consumption decreased with increased pressure and fo r that reason the dashed l i n e was f i t t e d to the 12° C data by le a s t squares. 0 - 8 0 - 6 0 - 4 0 - 2 O O O O O O 0 O O IO 2 0 Pressure (atmospheres) FIGURE 9> Rate of oxygen consumption with respect to pressure. temperatures were taken from a single collection during O O o IO c I 2 ° C o o o O - 12 C O o 3 0 4 0 Copepods tested at the two November 1965 ( U B C ) . 22 IV. Discussion Consideration of the variatio n s i n rate of oxygen con-sumption to endogenous and environmental factors i s important (1) i n order to evaluate the ef f e c t of techniques used on the data obtained, (2) i n order to evaluate the eff e c t and to interpret the meohanism of action of p a r t i c u l a r factors on oxygen consumption and (3) i n order to evaluate oxygen u t i l i z a t i o n and requirements i n the natural environment, A, Considerations of technique. The ef f e c t of tempera-ture, s a l i n i t y , l i g h t and density o f experimental animals, on rate o f oxygen consumption i s generally appreciated (Prosser and Brown, 1961), In addition, i f regular endogenous changes i n rate of oxygen consumption are present, data which are to he compared must be selected from the same stage of the rhythm. Irregular endogenous changes may be removed by continuous monitoring and s e l e c t i o n of comparable data, when the necessary equipment i s a v a i l a b l e . Pressure i s o r d i n a r i l y maintained at one atmosphere. However, when pressure i s tested as the variable a f f e c t i n g rate of oxygen consumption of aquatic organisms and the ex* perimental ohamber must be removed from under pressure to analyze oxygen, caution must be employed to ensure oxygen i s not released from s o l u t i o n due to temperature change as pressure i s released. Control experiments indicated that sudden release of pressure equivalent to 40 atm together with the change from 10° C to about 20° G during analysis 23 (enoompasslng a time period of about 10 min) did not r e s u l t i n release o f oxygen from s o l u t i o n . Two solutions of equal oxygen concentration, one kept at one atm and one kept at 40 atm for two hrs followed "by sudden release of pressure, agreed within one per cent (100$ saturation s f u l l scale) on a Beckman Oxygen Analyzer, Model 777, Therefore, under the experimental conditions used, release of oxygen from solut i o n d i d not prove to "be a problem. The importance of the effect o f the excitatory state of copepods on rate o f oxygen consumption (Berner, 1962:636) can not be emphasized too strongly i f reproducible r e s u l t s are to be obtained. E x c i t a t i o n of the copepods by t r a n s f e r or by d i r e c t exposure t o an environmental variable, may r e s u l t i n a q u a n t i t a t i v e l y unpredictable overshoot response of oxygen consumption (Ealorow, 1963; Grainger, 1958)* I f the experiment i s of short duration and the chamber volume i s small i n r e l a t i o n to the number of copepods tested, rate of oxygen consumption during overshoot may strongly bias the resultant r a t e . In contrast, when experiments are long i n duration (achieved i n closed systems by having a large r a t i o of water and hence oxygen to organism tested) time spent i n overshoot i s short i n comparison to the total length of time and consequently the measured rate of oxygen consumption i s l e s s biased by change i n rate daring overshoot. Some of the overshoot response may be minimized by acclimating the oopepods to the t e s t chambers p r i o r to t e s t (Conoverj 1956; Bemer, 1962), 24 In th© present study the effeots of the variables on rates measured were minimized by maintaining the variables constant or not allowing them to vary to l e v e l s at which oxygen consumption i s affected. Irregular endogenous changes oould not be removed since i n most oases rate of oxygen con'" sumption was not monitored continuously. The desire for better r e p r o d u c i b i l i t y of r e s u l t s and i the a b i l i t y to correct spurious changes i n rates w i l l neces-s i t a t e , i n subsequent investigations, continuous monitoring of oxygen consumption (Teal and Halcrow, 1962 and Halorow, 1963). B. E f f e c t of f a c t o r s . The e f f e c t of population density and l i g h t were studied p r i m a r i l y to determine i f e i t h e r s i g n i f i c a n t l y a f f e c t s rate of oxygen consumption. The pre-sence o f endogenous rhythms was investigated to determine i f measurements should be r e s t r i c t e d to a p a r t i c u l a r time period and to t e s t i f an endogenous rhythm i n locomotor a c t i v i t y was present. S a l i n i t y , oxygen concentration, pressure,*and temperature were investigated i n order to describe how these major environmental variables a f f e c t oxygen consumption. Increase i n population density r e s u l t s i n decrease i n rate o f oxygen consumption of 0. plumohrus as i s reported f o r Oalanas finmarohious (Gunner) (Zeiss, 1963). However, 0. plumohrus i s generally l e s s s e n s i t i v e to orowding. Zeiss stated the decrease i n oxygen consumption of 0. finmarchleus indicated the influence of some other f a c t o r and suggested increased metabolite concentration. The data 25 presented i n Figure 2 might appear to agree with t h i s hypothesis; however, i f metabolite accumulation i s the s i g -n i f i c a n t factor decreasing rate of oxygen consumption* one would expect a decrease i n rate of oxygen consumption with time at each density tested (or allowing for a threshhold e f f e c t * one should observe a decrease i n rate above a par-t i c u l a r density)* But* analysis o f the 24 hourly measure-ments o f rate of oxygen consumption at each density indicates that at d e n s i t i e s of 4-5 copepods / ml rate d i d not di f f e r ? s i g n i f i c a n t l y with time ( i * e * * rates measured during the f i r s t 12 hrs were the same as measured during the second 12 hrs) and copepods tested at a concentration of l e s s than 4 copepods / ml increased rate o f oxygen consumption with time ( i * e * * rate during the second 12 hrs was s i g n i f i c a n t l y higher than the f i r s t 12 h r s ) * One might also argue that the increase i n rate with time represents an endogenous i n -crease i n rate of oxygen consumption and consequently maln-tainance o f a constant rate i s a c t u a l l y a r e l a t i v e decrease* but i t should be observed that three densities tested i n the 4-5 copepods / ml density range d i d not d i f f e r s i g n i f i c a n t l y from the density o f l e s s than 4 copepods / ml* Hence, maintainance of a constant rate cannot be interpreted as a r e l a t i v e decrease* The data presented l n t h i s study f o r the e f f e c t of population density on rate of oxygen consumption of 0* plumohrus* therefore, do not support the hypothesis that metabolite accumulation i s responsible f o r deorease l n rate of oxygen consumption. At present, I can o f f e r no 26 alte r n a t i v e explanation f o r the observed decrease* The e f f e c t o f l i g h t was i n part investigated with the analysis for endogenous changes l n oxygen consumption* Ho difference l n rate of oxygen consumption between copepots kept i n continuous l i g h t and continuous dark could be demon* strated* However, i n one set of experiments ohange from dark to l i g h t d i d r e s u l t i n a s i g n i f i c a n t increase i n rate of oxygen consumption* Conover (1956) reported no ef f e c t of presence or absence o f l i g h t on rate of oxygen consumption of Aoartia olausi Glesbreoht and A c a r t i a tonaa Dana and i n con* t r a s t Marshall et a l * (1935) report a marked e f f e c t of l i g h t on rate of oxygen consumption of C* finmarohious* Marshall et a l * (1935) eliminated 17V l i g h t as the faotor causing s i g n i f i c a n t increase i n rate of oxygen consumption, although exposure to UV l i g h t d i d r e s u l t i n increased mortality* Also., Bingleberg (1961, 1964) has demonstrated that d i f f e r e n t l i g h t i n t e n s i t i e s and rates of change of i n t e n s i t y of laboratory i l l u m i n a t i o n can a f f e c t looomotory a c t i v i t y o f the cladooeran Daphnla magna Straus* In most studies of oxygen consumption* the e f f e c t of l i g h t or dark i s not determined, but rather experimental conditions are maintained uniform* Since l i g h t i s correlated with so many responses (e.g.., Gushing, 1951; Lewis, 1959; Moore and O'Berry, 1957; Bingleberg, 1961,1964) more in v e s t i g a t i o n concerning i t s p h y s i o l o g i c a l e f f e c t i s warranted* Harris (1963) reported experimental demonstration of an i n t r i n s i c rhythm i n locomotor a c t i v i t y i n the zooplanktors 27 D. magna and £• finmarehious and correlated these oircadian rhythms with ver t i c a l migration, Moore and 0'Berry (1957) also argue for the presence of an endogenous rhythm i n association with vertical migration. I f an endogenous rhythm related to vertical migration i s a general phenomen of zoo* plankton and i f the rhythm i s related to locomotor activity, i t s presence should be testable by measurement of oxygen consumption. However* 0. plumohrus demonstrates no regular significant change i n rate of oxygen consumption. Therefore* one might oonclude that C. plumohrus does not migrate, but Zenkevitoh (1963:793) reports Oalanas tonsas (0. plumohrus) to be both a daily and seasonal vertical migrator. Alter-native explanations of the absence of a rhythm cannot be ex-cluded. Other possible explanations are (1) the populations of oopepods tested may have been asynchronous, (2) the rhythm may be ephemeral and henoe disappears when the copepods are taken into the laboratory and tested i n the Warburg respirometer, (3) the rhythm might not be related to loco-motor activity, (4) active v e r t i c a l migration might only be a funotion of less than half of the population (Moore, 1955; Moore and 0'Berry, 1957) and therefore animals tested might have been selected from non-migrators present i n the same populations or (5) the method of monitoring oxygen consumption may not be sensitive enough. However, i t should be kept l n mind that the response measured by Harris was at least a "semi-persistent" population phenomena measured under labora-tory conditions. S t i l l another po s s i b i l i t y i s that Harris 28 a c t u a l l y measured an endogenous rhythm i n maintainanoe of v e r t i c a l p o s i t i o n rather than a locomotor rhythm since down* ward movement (e s p e c i a l l y i n nature) need not necessarily imply only passive sinking. Thus, with reference to the eff e c t of the remaining environmental factors studied on measurement of oxygen oon* sumption, crowding i s a s i g n i f i c a n t factor only at concen-t r a t i o n s when density i s equal to or greater than f i v e copepods / ml, neither l i g h t nor dark cause difference unless the copepods are changed from one to the other during or just p r i o r to the t e s t s , and t e s t s need not he r e s t r i c t e d to a p a r t i c u l a r time o f the day. However, during the summer random s i g n i f i c a n t increases i n rate of oxygen consumption do occur* Since oxygen consumption was calculated from measurements taken at the termination o f the t e s t , rates could not he cor-rected f o r these changes* Furthermore, i t i s not known i f these changes are " r e a l " or i f they merely r e f l e c t the experimental technique* Hence, the data must he considered a maximum estimate of oxygen consumption* Response to temperature i s enlightening and consideration of t h i s response i s important to the remainder o f the data* Bate of oxygen consumption inoreased "both l i n e a r l y (Figure 6) and non-linearly (Figure 5) over a temperature range of 5°-20° 0 when plot t e d i d e n t i c a l l y and as wel l * the l i n e a r response d i f f e r e d by sample variance and by elevation d i f -ference* One of the l i n e s d i f f e r i n g by elevation was derived from copepods c o l l e c t e d from a d i f f e r e n t season and l o c a l i t y , 29 disallowing the conclusion that a quantitative difference indicates a b i o l o g i c a l difference ( t h i s being due to sea-sonal adaptation, see Oonover (1959) and Marshall and Grr (1958))* However, the difference i n the l o c a l i t y strongly implies that the populations are b i o l o g i c a l l y d i s t i n c t . Thus, various aspects of each of the sets of oxygen consump-t i o n data suggest that each of the sets of data i s collected from a d i f f e r e n t b i o l o g i c a l population. In addition, each of the sets of temperature data indicates a d i f f e r e n t h i s t o r y of thermal acclimatization i n each of the populations studied. The slopes o f the l i n e s however, do not vary, thereby i n d i c a t i n g that Q^0 does not change with season or population tested. The general response of non-proportional increase or decrease of rate of oxygen consumption at 20° 6 indicates that t h i s temperature i s near the upper l e t h a l l i m i t . The e f f e c t of s a l i n i t y on rate of oxygen consumption of copepods i s v a r i a b l e . Marshall et a l . (1935) and Anraku (1964) report rate of oxygen consumption of 0. finmarehious decreases with decrease i n s a l i n i t y . A s i m i l a r decrease i s reported f o r Centropaa;ea hamatus ( L i l l j e b o r g ) (AnrakUi 1964). In contrast, lance (1965) reports a consistent increase i n rate of oxygen consumption of A. tbnsa with decrease i n s a l i n i t y . 0. plumohrus appears to respond i n an intermediate fashion with no s i g n i f i c a n t change i n rate of oxygen consump-t i o n over a range of 20*»35 ppt with a s i g n i f i c a n t increase at 10 ppt and a s i g n i f i c a n t decrease at 45 ppt. Comparative data from Calanus spp. and PIeurobrabhla babhel Agassiz indicate 30 a constant or s l i g h t l y increasing rate of oxygen consumption over a range of 80-35 ppt and a marked increase i n rate at lower or higher s a l i n i t i e s (Topping, unpublished data)# Sample variance of the two sets of data presented were un«* equal i n d i c a t i n g that the population from which the data were c o l l e c t e d are b i o l o g i c a l l y d i f f e r e n t . However, the two re-sponses are not quantitatively d i f f e r e n t . The manner i n which s a l i n i t y a f f e c t s oxygen consump-t i o n of crustaceans i s s t i l l disputed (e_.gj. * Schlieper, 1929; Plemister and Plemister, 1951; l o f t s , 1956; Gross, 1957; Potts and Parry, 1964)• lance (1965) reported maintalnanoe of s l i g h t hypertonioity with decrease i n s a l i n i t y i n A. tonsa and i n view of considerations reported by Potts (1954), t h i s response should require l i t t l e energy u t i l i z a t i o n . The tech-nique employed i s d i f f i c u l t and the data require v e r i f i c a t i o n . It remains possible that increased rate may be due to i n i t i a l bursts of locomotor a c t i v i t y . That oxygen concentration may act to regulate rate of oxygen consumption i s well known (Prosser and Brown, 1961). However, evidence that oxygen concentration may act to a f f e c t oxygen consumption of copepods i s r e s t r i c t e d to one report (Marshall et a l . , 1935). The present study indicates that rate of oxygen consumption of 0. plumchrns i s r e s t r i c t e d by concentrations l e s s than 3 cc oxygen per l i t e r and that the minimum l e t h a l concentration i s about one co oxygen per l i t e r . The 1964 data do not c l e a r l y demonstrate t h i s observation be-cause rate of oxygen consumption of these copepods was at a 31 minimal l e v e l and the difference i n rate dae to oxygen concentration was small. Also, when the rates of the copepods tested i n May 1965 were corrected for s i z e d i f f e r -ence, experimental error as w e l l as rate of oxygen consump-t i o n was m u l t i p l i e d "by the same factor and hence no difference i n rate was shown. Since the rates of winter acclimatized animals i s lower than summer animals, the above considerations imply that there would be a correspondingly smaller effect of oxygen concentration. Comparative data for Calanus spp, and P. bachei indicate a response s i m i l a r to that reported fo r C_, plumohrus. However, rates of both planktors at 5° C are not reduced u n t i l oxygen concentrations are reduced to 1-2 oo oxygen per l i t e r . The data may be interpreted to Indicate that oxygen concentration i s e s s e n t i a l l y unimportant i n most of the open ocean, but the factor may be important i n coastal areas and c e r t a i n l y should be considered i n fresh-water environments. Pressure has been proposed to be a factor of importance to marine zooplankton (Moore and Corwin* 1956; Moore and O'Berry, 1957), but again evidence of the effect of pressure on oxygen consumption i s r e s t r i c t e d to one study (Uapora, 1964), JSTapora reported that rate of oxygen consumption of the prawn S y s t e l l a s p i s d e b i l i s M.-Bdwards increased with increase i n hydrostatic pressure and that at about 900 m the ef f e c t of pressure i s equal and opposite to that of tempera-ture. Teal ( i n manuscript) has studied the effeot of pres-sure on rate of oxygen consumption of various larger 32 orustaoeans and euphausids and has obtained variable r e s u l t s (e*£*, Thysanopoda monooantha Ortman increases rate of oxygen consumption with increase i n pressure, T. t r i o n s p i d a M. Edw* undergoes e s s e n t i a l l y noi change i n rate and T. obtusifrons Sars decreases rate )• The rate of oxygen consumption of 0* plumchrus was not s i g n i f i c a n t l y changed with increase i n pressure equal to about 40 atm (or equivalent to about 400m)• I observed a s i m i l a r response i n a fresh-water daphnid Baphnia spp* which was c o l l e c t e d from a lake with a maximum depth not exceeding 15 m* In view of the r e s u l t s thus f a r obtained and because of the paucity of taxa tested, general-i z a t i o n of the eff e c t of pressure on oxygen consumption of planktonie crustaceans i s impossible* However, eff e c t of pressure on oxygen consumption of C* plumchrus may have been masked by the technique employed (see Sec. II G and Sec* IV A)* I f the ef f e c t of pressure i s hidden* then the regression l i n e shown i n Figure 9 fo r the 12° C data ( s i g n i f i c a n t at P < 0*05) may give a better i n t e r p r e t a t i o n of the effect of pressure* In t h i s case* the data presented give an i n t e r -pretation of the minimum effect o f pressure* C* Oxygen u t i l i z a t i o n i n nature* I n i t i a l l y , the temp-erature data indioate that data c o l l e c t e d from copepods taken from d i f f e r e n t c o l l e c t i o n s ( i n t h i s study equal d i f f e r e n t sample dates) may be from d i f f e r e n t b i o l o g i c a l populations* Since the ef f e c t of a l l factors were not determined on a single c o l l e c t i o n of copepods, the separate responses may not be grouped and argued to represent the response of a single 33 population of G* plumohrus* Bather* a generalized response of C. plumohrus* not s p e c i f i c to a p a r t i c u l a r population, to the fac t o r s tested i s obtained* This i s i n no way d e t r i -mental to i n t e r p r e t a t i o n o f the general p i c t u r e of energy u t i l i z a t i o n of G* plumohrus i n nature* The environmental factors considered i n t h i s study (e.g*» s a l i n i t y * temperature or oxygen concentration may vary ac-cording to the p a r t i c u l a r part of the marine environment studied* Light and pressure w i l l always decrease and i n -crease respectively with increase i n depth* Temperature w i l l also generally decrease with lnerease i n depth, except i n areas o f extreme mixing wherein temperature may remain essen-t i a l l y constant or with a termal inversion* S a l i n i t y and ox-ygen concentration w i l l remain e s s e n t i a l l y constant with increase i n depth i n the open ocean, but i n coastal s i t u a -t i o n s , p a r t i c u l a r l y fjords and i n l e t s , s a l i n i t y may increase and oxygen concentration decrease markedly with depth* Therefore, according to variance of the environmental factors considered, oxygen consumption might vary with depth ac-cording to the environment. Comparison of the two l o c a l i t i e s from which C, plumohrus were oollected for t h i s study are given i n Table V, Zenkevitoh (1963) reported that Oalanas tonsus (Calanus plumchrns) occurring i n the north P a c i f i o migrates v e r t i c a l l y both seasonally and d i u m a l l y * Therefore, MoLaren fs (1963) hypothesis that the adaptive value of v e r t i c a l migration of zooplankton i s to (1) be present i n or near the euphotio 34 Table V, Summary of water properties with depth and season in San Juan Channel and Indian Arm (Tulley and Bodimeadt1957; Waldiohuk, 1957; Gilmartin, 1962). -Depth (m) Temperature (° G) Salinity (ppt) Oxygen (ocOg/l) San Juan Channel: June'50 Winter June150 Feb.150 June*31 Feb/31 0 13. 6 . 24.0 28.5 8.2. 7.5 150 8 6 30.6 30.4 6.0 6.0 Indian Arm: June159 Uov,»57 Sum.Max Win.Min May '59 Oct.159 0 15- 8 - 15 16 9.0 6.0 100 7 7 28 27 4.5 3.0 200 7 7 28 28 2.0 2.2 zone to feed and yet (2) to sink lower in the water body where* primarily due to lower temperature, less energy w i l l be used and (3) the energy i s shunted to growth of larger more fecund plankton, which in turn (4) produce more offspring allowing seleotion for ve r t i c a l l y migrating forms, i s of special signi-ficance. Migration to or through discontinuity layers w i l l presumably result in exposure of the plankton to wide ranges of environmental factors and overshoot i n physiological ad-justment to these properties should result. Therefore, overshoot i n rate of oxygen consumption (although maximizing the quantity of response to a particular factor) i s con-sidered part of the normal response and hence* i s not removed from the results presented in this study. Due to lack of better data, responses to the environ-mental factors are considered to be additive (for limits to this assumption see Kinne (1964) and Hapora (1964)). 35 9L* Pl.tuoehroB in the open ocean shoald decrease oxygen ut i l i z a t i o n with depth primarily due to temperature. In a coastal situation such as San Juan Channel, rate of oxygen consumption may deorease slightly during summer with depth due to decrease i n temperature, hut should undergo essentially no change during most of the year. Consideration of temperature, sa l i n i t y and oxygen concentration in another coastal body of water (Indian Arm, a B r i t i s h Columbia fjord) also i n -dicates rate of oxygen consumption should decrease with depth. However, in this case oxygen consumption should decrease primarily because of oxygen concentration since higher temp-eratures are above the halooline and the surface s a l i n i t i e s reported should be lethal to C. plumohrus. Below the halo-cline, temperature decreases l i t t l e . Therefore, i n eaoh of the situations described the copepod G. plumohrus should de-crease rate of oxygen consumption with depth, except pos-sibly when passing through a thermal inversion i n the water body. Consequently* change i n rate of oxygen consumption with depth i s i n general agreement with McLaren's hypothesis of energy u t i l i z a t i o n . However, i n particular ooastal situations oxygen concentration or sali n i t y might act in concert with temperature to decrease energy u t i l i z a t i o n . This conclusion might appear to be a "truism", but i n view of Hapora's (1964) report and Teal's tentative results, such a conclusion i s not axiomatic and cannot therefore necessarily be generalized to other species of zooplankton. Various peculiarities of vertical migration observed 3 6 both i n the f i e l d and i n the laboratory (Hansen, 1951; Harder, 1957; lance, 1962; Moore and O'Berry* 1957), together with the report that zooplankton w i l l tend to regulate t h e i r d i s t r i b u t i o n such that energy u t i l i z a t i o n i s maintained at a constant rate (Bishop, 1964) suggest that in t e r p r e t a t i o n o f s p e c i f i c patterns of plankton d i s t r i b u t i o n and movement i n terms of physiology and p a r t i c u l a r l y energy u t i l i z a t i o n may be f r u i t f u l . 37 V. Summary 1* Oxygen consumption of C_. plumohrus with respect to environ-mental and endogenous changes was studied. Copepodid 7 stages were used throughout the study and speoimens were collected from San Juan Channel, Washington and Indian Arm, B r i t i s h Columbia, 2. Bates of oxygen consumption were determined using standard closed chamber technique described by Conover (1956) and Warburg respirometry. 3. Bate of oxygen consumption of C. plumohrus i s limited by extreme population densities and this limitation i s not attributable to metabolite accumulation. 4. The relation between volume of sample ohamber and duration of test i s important i n evaluating rate of oxygen consump-tion. 5. Temperature data indicate that for various measurements of oxygen consumption to be comparable, rates must be measured on the same collection of copepods. Either due to the real distribution of copepods or due to the laok of reproducibility of measuring rate of oxygen consump-tion of copepods* data from subsequent oolleotions within the same season and from the same l o c a l i t y are sta-t i s t i c a l l y different. 6. Changes i n rate of oxygen consumption of 0.' plumohrus in response to environmental and endogenous faotors may be grossly summarized as follows: a. Bate of oxygen consumption i s significantly decreased 38 "by population densities of 5 or more copepods / ml, b. Regular endogenous changes i n rate of oxygen con-sumption do not appear to occur, c. The presence or absence of l i g h t does not s i g n i f i -cantly a f f e c t rate of oxygen consumption, but change from one condition to the other may cause a s i g n i f i -cant increase, d. Hate of oxygen consumption may be described as d i r e c t l y proportional (being variously l i n e a r and non»linear) to temperature throughout the range of 5°-20° 0. e. Hate of oxygen consumption does not vary s i g n i f i c a n t l y over a s a l i n i t y range of 20-35 ppt, but increased at 10 ppt and decreased at 45 ppt, f . Hate of oxygen consumption decreases to a minimal rate below an oxygen concentration of three cc oxygen per l i t e r , g. Bate o f oxygen consumption i s not s i g n i f i c a n t l y af-fected by increased hydrostatic pressure corres-ponding to a depth of about 400 m. ?• In general, the data are consistent with McLaren^s (1963) theory of energy u t i l i z a t i o n and v e r t i c a l migration, although temperature does not appear to always be the most s i g n i f i c a n t f a c t o r . Interaction and v a r i a t i o n of environmental faetors may explain some of the complexity of v e r t i c a l d i s t r i b u t i o n . 39 VI• Literature Cited Anraku, M. 1964. Influence of the Cape Cod Canal on the hydrography and on the copepods in Buzzards Bay and Cape cod Bay, Massachusetts, II, Respiration and feeding, Limnol. Ooeanog. 9[Z):195«?E06, Berner, A, 1962, Feeding nand respiration in the copepod Temora longicorals (Muller). J, mar, h i o l . Ass, U.K. 42:625-640, . - "T Bishop, J,W, 1964, Zooplankton metabolism: oonstancy in the natural habitat. Abstracts of the 27th Ann* Meeting of the American Society of Limnology and Oceanography, p, 4, Brodsky, K.A. 1950, Calanoida of the far eastern and polar seas of the U.S.S.E. Tabl. and ffaune R.R.S.S. No, 35, Brodsky, K.A. 1957, Copepods (Calanoida) and the zoogeo-graphioal distribution i n the northern part of the Pacific Ooean and neighbouring waters* Zool* Inst* Akad. Sauk, U.S.S.R, 222 pp* Cenover, H.J. 1956. Oceanography of Long Island Sound. VI* Biology of Aoartia olausl and A. tonsa. B u l l . Bingham Ooeanogr. C o l l . 15:156-233. Gonover, R.J. 1959* Regional and seasonal variation i n the respiratory rate of marine copepods* Limnol. Qceanog* 4;259-268* Gushing* D.H. 1951* The vertical migration of planktonic orustaeea* B i o l . Rev. 26(2): 158-192* Enright* J.T. 1965* The search for rhythm!city i n biological time«*series. J. Theoret. B i o l * 8:426-468* Plemister, L.J. and Plemister* S.C. 1951* Chloride ion regulation and oxygen consumption in the crab Ooypode albicans (BosgJ. Biol* B u l l , 101:259-273. Preund, J.E., P.E. Livermore and I. Miller. I960. Experimental S t a t i s t i c s . Prentice-Hall* Inc. Englewood C l i f f s , N.J. v i i i f 132 pp. Gilmartin* M. 1962. Annual cyclic changes i n the physical oceanography of a B r i t i s h Columbia fjord. J. Pish. Res. Bd. Canada. 19(5):921-974. Grainger* J.N.R. 1958. F i r s t stages i n the adaptation of poikilotherms to temperature change. In Physiological Adaptation (Ed.) C L . Prosser, 1958* pp* 79-91. 40 Gross, W.J. 1 9 5 7 . An analysis of response ;bo osmotic stress i n selected decapod crustaoea. B i o l . B u l l . 1 1 2 : 4 3 - 6 2 . Halorow, K. 1 9 6 3 . Acclimation to temperature in the marine copepod, Oalanus finmarchious (Gunner). Limnol. Oceanog. 8 ( l ) : l - 8 . ~ , " — J s -Hansen, V.K. 1 9 5 1 . On the diurnal migration of zooplankton in relation to the discontinuity layer. J. Cons.8 i n t . E x p l 8 r . Mer.! IV: 2 3 1 - 2 4 1 . n Harder, W. 1 9 5 7 . Verhalten von Organism gegenuber der Sprungsohichten. Anee Biol.' 3 3 : 2 2 7 - 2 3 9 . " Harris, J.E. 1 9 6 3 . The role of endogenous rhythms i n vertical migration. J.' mar, b'iol. Ass. U.K. 4^': 1 5 3 - 1 6 6 . Kinne, 0. 1 9 6 4 . The effects of temperature and salinity on marine and brackish water animals. II. Salinity and temperature salinity combinations. Oceanog. Mar. B i o l . Ann.' Hey. : 2 J : 2 8 1 * 2 3 9 . Lance, J. 1 9 6 2 . Effects of water of reduced sal i n i t y on the vertical migration of zooplankton. J. ajar.' hjLol. Ass. U.K. , 4 2 : 1 3 1 - 1 5 4 . Lance, J. 1 9 6 5 . Respiration and osmotic behaviour of Acartia tons a in diluted sea water. Oomp. B'ioohem. Pkysiol. 1 4 : T55-T65. . Lewis, A.G. 1 9 5 9 . The vertical distribution of some inshore copepods in relation to experimentally produced conditions of light and temperature. B u l l . Mar. Sci. Gulf and Oarib. 9 ( 1 ) : 6 9 ~ 7 8 . ~ ~ Lofts, B. 1 9 5 6 . The effects of sal i n i t y changes on the respiratory rate of the prawn Palaemonetes varians (Leach),. J. exp. B i o l . 3 3 : 7 3 0 - 7 3 6 . Marshall, S.M., A.G. Meholls and A.P. Orr. 1 9 3 5 . On the biology of Calanus finmarchious. Part VI. Oxygen consump-tion i n relation to environmental conditions. J. mar, b i o l . Ass. U.K. 2 0 ( l ) : l - 2 7 . Marshall* S.M. and A.P. Orr. 1 9 5 8 . On the biology of Oalanus finmarchious. X. Seasonal changes in oxygen consumption. J. mar. b i o l . Ass. U.K. 3 7 : 4 5 9 - 4 7 2 . McLaren, I.A. 1 9 6 3 . Effects of temperature on growth of zoo-plankton and the adaptive value of vertical migration. J. Fish. Res. Bd. Panada. 2 0 ( 3 ) : 6 8 5 - 7 2 7 . Moore, H.B. 1 9 5 5 . Variations In temperature and light response within a plankton population. B i o l . B u l l . 1 0 8 ( 2 ) : 1 7 5 - 1 8 1 . 4 1 M o o r e , H . B . a n d E . G . C o r w i n . 1 9 5 6 . T h e e f f e c t s o f t e m p e r a t u r e , i l l u m i n a t i o n a n d p r e s s u r e o n t h e v e r t i c a l d i s t r i b u t i o n o f z o o p l a n k t o n . B u l l . M a r . S c i . G u l f a n d O a r i h . 6 ( 4 ) : 2 7 3 ^ 2 8 7 . M o o r e , H . B . a n d D . L . 0 ' B e r r y . 1 9 5 7 . P l a n k t o n o f t h e F l o r i d a c u r r e n t . I V . F a c t o r s i n f l u e n c i n g t h e v e r t i c a l d i s t r i b u -t i o n o f some common c o p e p o d s . B u l l . M a r . S c i . G u l f a n d P a r i p . J 7 ( 4 ) : 2 9 7 - 3 1 5 . " M o r i , T . 1 9 3 7 . T h e P e l a g i c C o p e p o d s f r o m t h e N e i g h b o u r i n g W a t e r s o f J a p a n . 1 5 0 p p . N a p o r a , T . A . 1 9 6 4 . T h e e f f e c t o f h y d r o s t a t i c p r e s s u r e o n t h e p r a w n , S y s t e l l a s p i s d e M l i s . S y m p . o n E x p . M a r . E o o l . O o c a . P u b l . N a r r a g a n s e t t M a r . L a b . N o . 2 . p p . 9 2 - 9 4 . P a m a t m a t , M . M . 1 9 6 5 . A c o n t i n u o u s - f l o w a p p a r a t u s f o r m e a s u r i n g m e t a b o l i s m o f b e n t h i c c o m m u n i t i e s . L i m n o l . O o e a n o g . 1 0 ( 3 ) : 4 8 6 - 4 8 9 . — P o t t s , W . T . W . 1 9 5 4 . T h e e n e r g e t i c s o f o s m o t i c r e g u l a t i o n i n b r a c k i s h a n d f r e s h w a t e r a n i m a l s . J . e x p . B i o l . 3 1 : 6 1 8 - 6 3 0 . P o t t s , W . T . W . a n d P a r r y , G . 1 9 6 4 . O s m o t i c a n d I o n i c R e g u l a t i o n i n A n i m a l s . P e r g a m o n P r e s s , L o n d o n . 4 2 3 p p . P r o s s e r , C L . a n d F . A . B r o w n , J r . 1 9 6 1 . C o m p a r a t i v e A n i m a l P h y s i o l o g y . W . B . S a u n d e r s C o . , P h i l a d e l p h i a , i x / 6 8 8 p p . R a y m o n t , J . E . G . 1 9 6 3 . P l a n k t o n a n d P r o d u c t i v i t y i n t h e O c e a n s . P e r g a m o n P r e s s , New Y o r k , v i i i / 6 6 0 p p . R a y m o n t , J . E . G . a n d D . T . G a u l d . 1 9 5 1 . T h e r e s p i r a t i o n o f some p l a n k t o n i c c o p e p o d s . £ . m a r , b i o l . A s s . U . K . 2 9 : 6 8 1 - 6 9 3 . R i n g e l b e r g , J . 1 9 6 1 . A p h y s i o l o g i c a l a p p r o a c h t o a n u n d e r -s t a n d i n g o v v e r t i c a l m i g r a t i o n . P r o c . A c a d . S c i . A m s t . s e r . G . 6 4 : 4 8 9 - 5 0 0 . R i n g e l b e r g , J . 1 9 6 4 . T h e p o s i t i v e l y p h o t o t a c t i c r e a c t i o n o f D a p h n i a m a g n a S t r a u s : A c o n t r i b u t i o n t o t h e u n d e r s t a n d i n g o f d i u r n a l v e r t i c a l m i g r a t i o n . N e t h . J . S e a R e s . 2 , ( 3 ) : 3 1 9 - 4 0 6 . S c h l i e p e r , C . 1 9 2 9 . U b e r d i e E i n w i r k u n g n i e d e r e r S a l z k o n z e n -t r a t i o n e n a u f m a r i n e O r g a n i s m e n . Z . v e r g l . P h y s i o l . 9 : 4 7 8 - 5 1 4 . S n e d e c o r , G . W . 1 9 5 6 . S t a t i s t i c a l M e t h o d s . 5 t h e d . , I o w a S t a t e C o l l e g e P r e s s , A m e s , I o w a . S w e d , F . S . a n d C . E i s e n h a r t . 1 9 4 3 . T a b l e s f o r t e s t i n g r a n d o m -n e s s o f g r o u p i n g i n a s e q u e n c e o f a l t e r n a t i v e s . A n n . M a t h . S t a t . 1 4 : 6 6 - 8 7 . 4 2 T a n a k a , 0 . 1 9 5 6 , T h e p e l a g i c c o p e p o d s o f t h e I z u r e g i o n , m i d * d i e J a p a n . S y s t e m a t i c A c c o u n t I . F a m i l i e s . G a l a n i d a e a n d E u c a l a n i d a e . P u b l . S e a t o m a r , h i o l . L a b . j > ( 2 ) : 2 5 1 - 2 7 2 . T e a l , J . M . a n d Z . H a l c r o w . 1 9 6 2 . A t e c h n i q u e f o r m e a s u r e m e n t o f r e s p i r a t i o n o f s i n g l e c o p e p o d s a t s e a . £ . C o n s , i n t . E x p l o r . M e r . 2 7 ( 2 ) : 1 2 5 - 1 3 0 . T u l l y , J . P . a n d A . J . D o d i m e a d . 1 9 5 7 . P r o p e r t i e s o f t h e w a t e r i n t h e S t r a i t o f G e o r g i a , B r i t i s h C o l u m b i a a n d i n -f l u e n c i n g f a c t o r s . J . F i s h . R e s . B d . C a n a d a . 1 4 ( 3 ) : 2 4 1 -3 1 9 . U m b r e i t , W . W . , E . H . B u r r i s a n d J . F . S t a u f f e r . 1 9 5 7 . M a n o m e t r i o T e c h n i q u e s . B u r g e s s P u b l . C o . , M i n n e a p o l i s , M i n n , i i i f 3 3 8 , p p . W a l d i o h u k , M . 1 9 5 7 . P h y s i c a l o c e a n o g r a p h y o f t h e S t r a i t o f G e o r g i a , B r i t i s h C o l u m b i a . J . F i s h . R e s . B d . C a n a d a . 1 4 ( 3 ) : 3 2 1 - 4 8 6 . Z e i s s , F . B . 1 9 6 3 . E f f e c t s o f p o p u l a t i o n d e n s i t i e s o n z o o -p l a n k t o n r e s p i r a t i o n r a t e s . L i m n o l . O o e q n o g . 8 : 1 1 0 - 1 1 5 . Z e n k e v i t o h , L . 1 9 6 3 . B i o l o g y o f t h e S e a s o f t h e U . S . S . R . ( t r a n s ) . G e o r g e A l l e n & U n w i n L t d . , L o n d o n . 9 5 5 p p . 4 3 A p p e n d i x I* B e p l i o a t e m e a s u r e m e n t s o f r a t e o f o x y g e n c o n -s u m p t i o n ( u l 0 2 u s e d / c o p e p o d / h r ) w i t h r e s p e c t t o c r o w d i n g . D a t a w e r e . c o l l e c t e d d u r i n g J u n e 1 9 6 4 a t FHL C r o w d i n g ( c o p e p o d s / m l ) 1 , 0 . 3 , 3 4 . 0 4 . 3 5 . 0 1 . 0 6 0 . 8 1 0 . 4 5 0 . 7 8 1 . 0 9 0 . 2 8 1 . 2 1 1 . 0 8 1 , 3 7 1 , 0 0 2 . 1 0 1 . 4 1 1 . 0 5 1 , 3 7 0 . 9 2 0 . 2 9 1 . 2 1 0 . 9 1 1 . 1 7 1 . 0 5 0 . 8 9 1 . 2 1 1 . 1 7 1 . 1 7 0 . 5 8 0 * 8 8 * 1 . 4 1 1 . 1 1 1 . 5 6 0 . 6 0 0 * 6 5 1 . 0 1 1 . 1 6 0 . 3 9 0 . 4 9 0 * 6 5 1 . 6 2 1 . 2 2 1 . 7 6 0 , 6 0 0 . 7 8 1 . 6 2 1 . 2 5 0 . 9 8 0 . 4 3 0 * 6 0 1 . 6 2 0 . 5 0 0 . 3 9 0 . 9 0 2 . 4 5 1 . 8 2 1 . 1 9 1 . 1 7 0 . 7 0 1 . 2 6 1 . 4 1 0 . 8 7 1 . 1 7 0 . 7 1 2 . 0 3 1 . 6 2 1 . 1 7 1 . 1 7 1 . 2 3 0 . 4 3 1 . 6 2 1 , 0 0 0 , 9 8 0 . 2 8 1 . 9 4 1 . 6 2 1 . 0 0 0 . 7 8 0 . 9 4 1 . 7 2 1 . 6 2 0 . 8 8 1 . 1 7 1 . 0 7 0 . 6 0 1 . 6 2 1 . 1 8 0 . 9 8 0 . 1 9 2 . 2 2 1 . 4 3 0 . 5 9 0 . 7 5 0 . 8 1 0 . 1 8 0 . 0 0 0 . 2 5 1 . 8 2 1 . 0 0 0 . 9 8 1 . 6 3 1 . 8 2 1 . 0 6 0 . 7 8 0 . 3 7 2 . 4 2 1 . 2 4 0 . 5 9 0 . 8 9 2 . 0 2 1 . 1 3 1 . 1 7 0 . 3 3 1 . 8 2 0 . 7 7 0 . 3 9 0 . 5 1 M e a n 1 . 2 4 1 . 1 5 1 . 0 0 0 . 9 5 0 . 7 0 S . E . 0 . 1 4 0 . 0 8 0 . 0 6 0 . 0 8 0 . 0 7 44 Appendix II.- Diel measurement of rate of oxygen consumption (ul 0 usea / copepod / hr). Mean values of replicate deter-minations are l i s t e d with standard error given below in parenthesis. Data for oolumns A and B were collected during June 1964 at FEEL and data for oolumns 0, D, and B were col-lected during November 1965 at BBC. Data l i s t e d under columns A, B, e t c . correspond to the.curves designated by the same letters i n Figures 3 and 4 of the text. Curves shown in Figs. 3 and 4 A B C D E # of replicates Gopepods / replicate 8-13 15 3 3 Determinations: . Time 10:00 pm 0*40 (0.21) 0.33 0.40 (0.23) (0.12) 1:00 am 0«58 .0.40- .0*25- 0.32-(0.13) (0.10) (0.08) (0.04) 2:00 1.17. (0*13) - -3:00 1.18- 1.09 0.69 0.56 0.57 (0.12) (0.16) (0.14) (0.17) (0.21) 4:00 -1.02-(0.10) l.oo: (0.94) -5:00 1.18 0.92 0.46 0.34 0*36 (0.08) (0.31) (0.01) (0.03) (0.03) 6:00 1.26-(0.11) 1.05 (0.02) -7:00 0.98. (0.26) .0.58. (0.04) 7:15 - - 0.35 (0.02) 0.23 (0.04) 0.39 (0.13) 8:00 1.41 (0.18) 0.60 (0.06) - • 9:00 1.27. 0.49 (0.04) (0.15) 10:00 0,70 0*60 0.47 0.53 0.62 (0.25) (0.08) (0.10) (0.06) (0.04) 11:00 1*31 0.43 0.60. 0.33 1.88 (0*15) (0.04) (0.11) (0.13) (0.46) 12:00 1.04 (0.14) 0.90-(0.02) - -45 Appendix II (Cont'd.) Carves shown i n Figs. 3 and 4 A ' B -• • -:i Cf4 3D E 1:00 pm 1.26 (0.12) 0.70 (0.04) 2:00 1.12- .0.71- 0.49 0.58 0.75 (0.15) (0.03) (0.12) (0.13) (0.25) 3:00 .1.08-(0.17) 1.23 (0.05) - -4:00 -1.09 0.28- 1.17 0.63 1.70 (0.18) (0.17) (0.33) (0.09) (0.55) 5:00 -1.23-(0.11) 0.94-(0.14) -6:00 1.42-(0.28) 1.07 (0.05) 7:00 0.27-(0.15) 0.19-(0.04) 8:00 1.16 (0.19) 0.75 (0.05) 9:00 1.16 0.25- 0.45 0.71 0.81 (0,19) (0.06) (0.04) (0.17) (0.38) 10:00 .1.34-(0.32) 1.63-(0.21) - • • 11:00 1.31 0.37- 0.46 0.78 0.88 (0.19) (0.06) (0.05) (0.18) (0.48) 12:00 -1.10-(0.27) 0.89-(0.40) -1:00 am .1.12. (0.29) 0.33 (0.04) 2:00 ,0.51. (0.16) 3:00 0.43 0.34 (0.15) 1.25 (0.10) (0.50) j 4 6 A p p e n d i x III. C o m p a r i s o n o f r a t e o f o x y g e n c o n s u m p t i o n ( o l 0 2 u s e d . / c o p e p o d / h r ) w i t h r e s p e c t t o l i g h t a n d d a r k a t f o u r t e m p e r a t u r e s . S t a n d a r d e r r o r s a r e l i s t e d i n p a r e n t h e s e s b e l o w t h e m e a n s . C o p e p o d s w e r e t e s t e d a t a c o n c e n t r a t i o n o f f i v e p e r t h r e e m l o f s e a w a t e r . T e s t s w e r e r u n d u r i n g J u n e 1 9 6 5 a t UBC. T e m p e r a t u r e D u r a t i o n o f ( 0 G ) t e s t ( h r s ) L i g h t D a r k 7 . 1 3 0 . 8 4 0 . 2 5 0 . 2 4 ( 0 . 0 1 ) 0 . 2 3 0 . 2 5 0 . 2 4 ( 0 . 0 2 ) 1 0 7 . 1 7 0 . 4 5 0 . 5 1 0 . 2 7 x 0 . 4 1 ( 0 . 1 0 ) 0 . 1 5 0 . 3 8 0 . 5 3 0 . 3 2 ( 0 . 1 2 ) 1 5 4 . 0 3 0 . 4 2 0 . 6 5 0 . 9 9 0 . 6 9 ( 0 . 1 7 ) 0 . 7 2 0 . 3 4 0 . 7 8 ( 0 . 0 6 ) 20 6 . 5 3 1 . 5 6 1 . 2 5 1 . 4 1 x 1 . 4 1 ( 0 . 1 0 ) 1 . 4 1 2 . 3 1 1 . 8 6 ( 0 . 4 2 ) 4 7 A p p e n d i x 1 7 . B a t e o f o x y g e n c o n s u m p t i o n ( u l 0 g u s e d / c o p e p o d / h r ) w i t h r e s p e c t t o t e m p e r a t u r e . S t a n d a r d e r r o r s a r e l i s t e d i n p a r e n t h e s e s b e s i d e t h e v a l u e s . D a t a p r e -s e n t e d f o r 1 9 6 4 a n d M a y 1 9 6 5 w e r e c o l l e c t e d a t F H L , w h e r e a s d a t a p r e s e n t e d f o r N o v e m b e r 1 9 6 5 w e r e c o l l e c t e d a t U B C . I n t h e t a b l e * X d e n o t e s u n c o r r e c t e d r a w d a t a a n d X 1 d e n o t e s d a t a c o r r e c t e d f o r s e a s o n a l s i z e v a r i a t i o n . D u r a t i o n T e s t # o o p e p o d s u l u s e d / c o p . / h r T e m p . o f t e s t s V o l . u s e d / t e s t ; : ( ° 0 ) ( h r s ) ( m l ) # o f t e s t s X X 1 D a t e : 4 / V I / 6 4 2 1 2 . 0 50 6 - 8 j 5 0 . 3 8 ( 0 . 0 4 ) 0 . 3 5 ( 0 . 0 4 ) 1 0 1 1 . 9 50 6 - 9 J , 5 0 . 6 9 ( 0 . 0 8 ) 0 . 6 3 ( 0 . 0 7 ) 1 5 1 2 . 0 50 6 - 9 ; 4 0 . 9 4 ( 0 . 0 7 ) 0 . 8 6 ( 0 . 0 6 ) 20 1 2 . 0 5 0 7 - 8 j • 5 0 . 9 6 ( 0 . 0 8 ) 0 . 9 0 ( 0 . 0 7 ) D a t e : 9 - 1 0 / V I / 6 4 2 1 2 . 0 50 9 - 1 0 ; ; 1 0 0 . 3 0 ( 0 . 0 2 ) 0 . 2 8 ( 0 . 0 2 ) 1 0 1 1 * 5 50 1 1 - 1 5 ; ; 1 0 0 . 5 7 ( 0 . 0 7 ) 0 . 5 2 ( 0 . 0 7 ) 1 5 1 2 . 0 50 9 * 1 1 ; 1 0 0 . 6 8 ( 0 . 0 4 ) 0 . 6 3 ( 0 . 0 4 ) 2 0 1 2 * 0 50 1 0 - 1 3 ; , 1 0 1 . 1 4 ( 0 . 0 4 ) 1 . 0 5 ) 0 . 0 4 ) D a t e : 1 9 / V / 6 5 4 3 6 . 9 3 5 5 ; • 1 0 0 . 1 2 ( 0 . 0 1 ) 0 . 2 2 ( 0 . 0 3 ) 1 0 3 6 . 6 3 5 3 - 5 ; , 1 0 0 . 2 0 ( 0 . 0 3 ) 0 . 3 7 ( 0 . 0 6 ) 1 2 * 5 3 5 . 5 3 5 1 - 5 , > 1 0 0 . 2 4 ( 0 . 0 4 ) 0 . 4 5 ( 0 . 0 7 ) 1 5 3 7 . 1 3 5 2 - 5 ; ; 1 0 0 . 3 5 ( 0 . 0 4 ) 0 . 6 7 ( 0 . 0 8 ) 2 0 1 5 . 3 3 5 5 , i 5 0 . 5 8 ( 0 . 0 7 ) 1 . 0 8 ( 0 . 1 3 ) D a t e : l l / X l / 6 5 3 2 6 . 5 3 5 5 ; 6 0 . 1 3 ( 0 . 0 2 ) 0 . 1 0 ( 0 . 0 1 ) 8 1 5 . 0 3 5 5 ; 1 0 . 3 9 0 . 3 0 ( 0 . 0 2 ) 1 0 3 . 0 1 0 5 - 8 ; 2 0 . 5 8 ( 0 . 0 6 ) 0 . 4 6 1 2 1 7 . 0 3 5 5 9 0 . 5 0 ( 0 . 0 6 ) 0 . 3 8 ( 0 . 0 5 ) 1 8 3 . 0 3 5 5 ; 2 0 . 6 7 ( 0 * 0 5 ) 0 . 5 2 ( 0 . 0 4 ) 4 8 A p p e n d i x V. H a t e o f o x y g e n c o n s u m p t i o n ( o l Og u s e d / o o p e p o d / h r ) w i t h r e s p e c t t o s a l i n i t y . S t a n d a r d e r r o r s a r e l i s t e d i n - p a r e n t h e s e s b e s i d e t h e v a l u e s . E x p e r i m e n t s r e p o r t e d f o r J u l y 1 9 6 4 w e r e c o n d u c t e d i n 5 0 m l c h a m b e r s a n d e x p e r i m e n t s r e -p o r t e d f o r M a y 1 9 6 5 w e r e c o n d u c t e d i n 3 5 m l c h a m b e r s . T h e e x p e r i m e n t s w e r e c o n d u c t e d a t FHL a n d a l l t e s t s w e r e r u n a t 1 0 ° 0. I n t h e t a b l e , X d e n o t e s u n c o r r e c t e d r a w d a t a a n d X * d e n o t e s d a t a c o r r e o t e d f o r s e a s o n a l s i z e v a r i a t i o n . D u r a t i o n T e s t # o o p e p o d s u l 0„ u s e d / o o p . / h r S a l i n i t y o f t e s t s Y o l . u s e d / t e s t ; — — — ( p p t ) ( h r s ) ( m l ) # o f t e s t s X Z f B a t e : 2 6 / Y I I / 6 4 2© 1 3 . 5 50 4 ; 2 5 1 2 . 8 50 4 ; 3 0 1 2 . 5 50 6 - 1 0 ; 3 5 1 2 . 3 5 0 4 ; B a t e : 1 8 / Y / 6 5 1 0 3 5 3 5 5 - 6 ; 2 0 3 5 3 5 5 ; 2 5 4 8 3 5 5 ; 3 0 3 5 3 5 4 ^ - 5 ; 3 5 3 5 3 5 3 - 5 ; 4 5 3 5 3 5 5 ; 3 £ . 0 2 ( 0 . 2 6 ) 0 . 9 3 ( 0 . 2 4 ) 3 0 . 7 8 ( 0 . 0 9 ) 0 . 7 2 ( 0 . 0 8 ) 1 0 0 . 7 6 ( 0 . 0 9 ) 0 . 7 0 ( 0 . 0 8 ) 3 0 . 7 6 ( 0 . 1 8 ) 0 . 6 9 ( 0 . 1 6 ) 4 0 . 5 6 ( 0 . 1 1 ) 0 . 9 5 ( 0 . 1 8 ) 5 0 . 2 2 ( 0 . 0 1 ) 0 . 4 2 ( 0 . 0 3 ) 5 0 . 2 3 ( 0 . 0 3 ) 0 . 4 3 ( 0 . 0 5 ) 5 0 . 2 4 ( 0 . 0 5 ) 0 . 4 4 ( 0 . 0 9 ) 5 0 . 3 2 ( 0 . 0 5 ) 0 . 6 0 ( 0 . 0 9 ) 4 0 . 1 3 ( 0 . 0 2 ) 0 . 2 6 ( 0 . 0 4 ) 4 9 A p p e n d i x V I , H a t e o f o x y g e n c o n s u m p t i o n ( u l Og u s e d / o o p e p o d / h r ) w i t h r e s p e c t t o o x y g e n c o n c e n t r a t i o n a n d t e m p e r a t u r e . S t a n d a r d e r r o r s a r e l i s t e d i n p a r e n t h e s e s b e s i d e t h e v a l u e s . D a t a r e p o r t e d f o r M a y 1 9 6 5 w e r e c o l l e c t e d a t FHL a n d d a t a r e p o r t e d f o r N o v e m b e r 1 9 6 5 w e r e c o l l e c t e d a t U B C , A l l t e s t s w e r e c o n d u c t e d i n 3 5 m l t e s t c h a m b e r s . I n t h e t a b l e , 2 d e n o t e s u n c o r r e c t e d r a w d a t a a n d X 1 d e n o t e s d a t a c o r r e c t e d f o r s e a s o n a l s i z e v a r i a t i o n , 1 T e m p . ( ° C ) : D u r a t i o n # c o p e p o d s u l 0 ? u s e d / c o p , / h r 0 P c o n e . o f t e s t s u s e d / t e s t ; - . -•— ( 3 o O g / l ) ( h r s ) # o f t e s t s X X* D a t e : S 4 - 2 6 / Y / 6 5 5 : 1 , 1 2 30 5 ; 3 0 . 1 1 ( 0 . 0 4 ) 0 . 2 1 ( 0 . 0 8 ) . 2 . 1 0 4 8 4 - 5 ; 3 0 . 2 1 ( 0 . 0 8 ) 0 . 4 0 ( 0 . 1 7 ) 2 . 2 4 5 3 5 ; 3 0 . 1 3 ( 0 . 0 1 ) 0 . 2 4 ( 0 . 0 2 ) 4 . 7 5 4 7 5 ; 3 0 . 1 4 ( 0 . 0 1 ) 0 . 2 5 ( 0 . 0 2 ) 5 . 2 8 4 6 4 - 5 ; 3 0 . 1 7 ( 0 . 0 4 ) 0 . 3 2 ( 0 . 0 7 ) 1 0 : 0 * 8 8 1 7 5 ; 3 0 . 2 8 ( 0 . 0 1 ) 0 . 5 1 ( 0 . 0 1 ) 2 . 0 2 1 3 5 ; 3 0 . 2 5 ( 0 . 0 4 ) 0 . 4 9 ( 0 . 1 0 ) 2 . 6 3 20 5 ; 3 0 . 1 8 ( 0 . 0 1 ) 0 . 3 2 ( 0 . 0 1 ) 3 . 6 4 2 0 4 - 5 ; 2 0 . 2 2 ( 0 . 0 1 ) 0 . 4 0 ( 0 . 0 1 ) 4 . 1 0 1 9 5 ; , 3 0 . 2 8 ( 0 . 0 3 ) 0 . 5 3 ( 0 . 0 6 ) 4 . 6 8 2 0 5 ; 3 0 . 2 6 ( 0 . 0 2 ) 0 . 5 0 ( 0 . 0 5 ) 1 5 : 1 . 8 7 1 2 5 ; , 3 0 . 2 3 ( 0 . 0 6 ) 0 . 4 4 ( 0 . 1 0 ) 2 . 5 3 1 2 5 ; , 3 0 . 1 9 ( 0 . 0 6 ) 0 . 3 7 ( 0 . 1 0 ) 3 . 1 6 1 5 5 ; , 3 0 . 3 3 ( 0 . 1 2 ) 0 . 6 3 ( 0 . 2 1 ) 4 . 7 8 1 5 5 ; » 3 0 . 3 3 ( 0 . 0 9 ) 0 . 6 1 ( 0 . 1 3 ) D a t e : 1 1 - 1 2 / X I / 6 5 3 : 0 . 8 0 2 6 4 ; i 0 . 0 3 0 . 0 3 2 , 1 7 2 6 4 i 2 0 . 0 9 ( 0 . 0 2 ) 0 . 0 8 ( 0 . 0 2 ) 2 . 6 7 2 7 4 ; 2 0 . 0 9 ( 0 . 0 1 ) 0 . 0 8 ( 0 . 0 1 ) 3 , 6 0 2 7 4 ; 2 0 . 1 3 ( 0 . 0 1 ) 0 . 1 2 ( 0 . 0 1 ) 5 . 8 5 2 6 4 • 2 0 . 1 9 ( 0 . 0 1 ) 0 . 1 7 1 2 : 0 . 8 5 1 5 4 ; 2 0 . 0 7 ( 0 . 0 2 ) 0 . 0 7 ( 0 . 0 2 ) 1 . 1 5 1 5 . 5 4 ; 2 0 . 2 3 ( 0 . 1 8 ) 0 . 2 1 ( 0 . 1 6 ) 2 . 0 0 1 7 4 ; 2 0 . 1 4 ( 0 . 0 3 ) 0 . 1 3 ( 0 . 0 3 ) 3 . 4 3 1 7 4 ; 2 0 . 6 3 ( 0 . 0 3 ) 0 . 5 8 ( 0 . 0 3 ) 5 . 8 5 1 7 4 ; 2 0 . 3 6 ( 0 . 1 0 ) 0 . 3 3 ( 0 . 0 9 ) 1 8 : 1 . 0 0 1 0 4 ; 4 0 . 1 0 ( 0 . 0 1 ) 0 . 0 9 ( 0 . 0 1 ) 1 . 1 7 1 2 2 ; 4 0 . 1 8 0 . 1 7 2 . 5 0 1 2 2 ; 4 0 . 4 8 ( 0 . 0 4 ) 0 . 4 4 ( 0 . 0 4 ) 6 . 0 0 1 4 4 ; 2 0 . 7 0 ( 0 . 0 3 ) 0 . 6 4 ( 0 . 0 3 ) 50 A p p e n d i x VII. B a t e o f o x y g e n c o n s u m p t i o n ( u l 0r> u s e d / c o p e p o d / h r ) w i t h r e s p e c t t o h y d r o s t a t i c p r e s s u r e . . . S t a n c t a r d e r r o r s a r e l i s t e d i n parentheses b e s i d e t h e v a l u e s . A l l e x p e r i m e n t s w e r e c o n d u c t e d d u r i n g l o v e m b e r 1 9 6 5 a t U B C . T e s t c h a m b e r s w e r e 1 0 m l . I n t h e t a b l e , X d e n o t e s u n c o r r e c t e d r a w d a t a a n d X 1 d e n o t e s d a t a c o r r e c t e d f o r s e a s o n a l s i z e v a r i a t i o n . P r e s s u r e ( a t m ) D u r a t i o n o f t e s t s ( h r s ) # c o p e p o d s u s e d / t e s t ; # o f t e s t s u l Og u s e d / c o p . / h r X 1 T e m p e r a t u r e : 1 0 ° C 1 . 0 0 2.90 5,8; 2 0 . 5 8 ( 0 . 0 6 ) 0 . 4 6 ( 0 . 0 5 ) 1 0 . 3 5 1 . 4 0 5 , 9 ; 2 0 . 4 1 ( 0 . 0 5 ) 0 . 3 2 ( 0 . 0 5 ) 1 3 . 8 0 3 . 1 5 5,8; 2 0 . 5 5 ( 0 . 0 1 ) 0 . 4 3 ( 0 . 0 1 ) 2 7 . 6 0 9.30 8; 1 0 . 4 0 0 . 3 1 3 1 . 0 0 1 . 7 0 5 , 9 ; 2 0 . 2 8 ( 0 . 0 4 ) 0 . 2 1 ( 0 . 0 3 ) 3 9 . 7 0 3 . 2 5 5 , 8 ; 2 0.36 ( 0 . 1 1 ) 0 . 2 8 ( 0 . 0 9 ) T e m p e r a t u r e : 1 2 0 1 . 0 0 1 9 . 0 0 3 6 . 2 0 1 . 6 5 1 . 7 5 7. 3 0 5 , 9 ; 2 9 , 1 1 ; 2 1 1 ; 2 0 . 6 5 ( 0 . 0 3 ) 0 . 5 2 ( 0 . 0 6 ) 0.34 ( 0 . 1 1 ) 0 . 5 0 ( 0 . 0 2 ) 0 . 4 1 ( 0 . 0 5 ) 0 . 2 7 ( 0 . 0 9 )
Thesis/Dissertation
eng
Zoology
Vancouver : University of British Columbia Library
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Graduate
A study of oxygen consumption in Colanus plumchrus Marukawa 1921 and implications on vertical migration
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