HALF-YEAR REPORT OF THE. PROSJECT "CULTIVATION OF CATFISH"

s 1 HALF-YEAR REPORT 1987. OF THE. PROSJECT "CULTIVATION OF CATFISH" by Erlend Moksness and Jakob Gj0seter Biological Station Fl0devigen 4800 Arendal His0Y June 1987

2 TABLE OF CONTENT Page Introduction 3 Meetings 3 Methods 3 Experimental groups 4 Collection of wild fishes spring-87 6 economy 6 Reports, Newspaper-article,radio-program etc. 7 Appendix (Terminated groups) 8 Appendix 1. 85-3 (spotted catfish) 8 Appendix 2. 86-2 (stripped catfish) 24 Appendix 3. 86-3 (spotted catfish) 35 References 36

3 INTRODUCTION The proj ect started 1. April 1987. From the same date two technical Assistants, Evy Lien and Sissel Rosseland were employed in the project. Three students, Mr. Vorren, participated in the project from 21/4 to 1/5-1987 and Kad R0dland and Ania Jablanska participated from 15/6 to 26/6-1987. The three first months of the project has concentrated on building up laboratory facilities and collection of local catfish. Installation of several new tanks has been delayed. These tanks are planned used mainly for the spawning stock. MEETINGS A steering group meeting were held at F10devigen 24/4-87. A planning group, R. Hole (Skretting A/S), 0. Lie (Fiskdir. Nutrition Inst.) and E. Moksness met 9. June in Stavanger and put together a proposal on "Foroptimalisering til Steinbit (Anarhichas sp.. ) i oppdrett" for the Norwegian Fisheries Research Board. METHODS The condition factor (C.F.) was calculated according to the formulae: C.F. = w * 100 / 13 (cm)., where w = wet weight (g) and 1 = length The %-growth was calculated according to the formulae: %-growth = (Wi + 1 - Wi) * 100 / Wi, where Wi = average wet weight (g) at measurement L and Wi+ 1 = average wet weight (g) at measurement i+1, used when groups are weighted every months. At feeding the feeder gave an INDEX from 0 to 5 to indicate if the fishes were eating well or not. The highest score was 5. In the calculating of food factor (FC) an average feeding INDEX between each measurement of the fishes was calculated. This average INDEX was later used to calculate an FC based upon the INDEX. The food factor (FC) were calculated according to the formulae: FC = WP * a / WW * b, where WP = wet weight (g) of the wet pellets, WW = average increase in wet weight (g) of the fishes, a = dry weight/wet weight relationship of the wet pellets in that specific period and b = - 20 % (dry weight/wet weight relationship of the fishes). Specific growth rate, SGR, were calculated according to the formulae:

SGR = (Ln Wt2 - Ln Wtl) / (t2-tl), where Wtl and Wt2 are wet weights of fishes at days tl and t2. 4

5 EXPERIMENTALS GROUPS At present four different groups of catfish are studied, mainly to follow their growth. The groups are listed in Table 1. The specific growth rate (SGR), %-growth together with some weights are given in table 2 for three of the groups. Two groups, 87-1 and 87-2, has been of specially interest to the project this spring. A egg-ball was caught near the Faeroe Island by a trawler (10/2-87) and the larvae hatched soon after (10-17/2 1987) in the Fishery Laboratory in Thorshavn. Maximum hatching were observed for three days, 12-14/2. Mean hatching date are set to 13/2-87 and defined as age day = O. ### of the newly hatched larvae were send Fl0devigen B.S. in two batches the 19/2 and 26/2 and at the laboratory mixed and divided into the two groups: 87-1 and 87-2. The differences between the two groups have mainly been that 87-1 has been startfeeded on Skretting "Elite Perle", while 87-2 have been startfeeded on Skretting "Elite Plus" and Artemia nauplii. The results shows that of the two groups, 87-2 have had the best growth (SGR = 3.3 %) and survival (approx. 60 %). In addition to growth and survival of the larvae groups (87-1 and 87-2), their behaviour were studied. In the following are some observation notified in the dairy: 1/3-7 dead larvae in 87-2 with food particle stuck to their body. 17/3 - The larvae in 87-1 followed the food particle sinking from surface to bottom and then eaten the food particle. 18/4 - The larvae in 87-2 eats the dry pellets floating in the surface, this was not observed in 87-1 where the larvae either eats the particle while it Sinks or lays on the bottom. 19/4 - The same observation as the 18/4 20/4 - "Elite plus" (0.6 mm) are hanging for a longer period in the surface than "elite pede" (0.6 mm). 22/4 - Stopped feeding 87-1 with "elite pede", started with "elite plus" 3/5 - A big larvae eating/ attacking a smaller larvae (half size) in 87-1 Artemia: 87-2 were fed newly hatched Artemia sauna nauplii from 9. March (3.75 g eggs/day) to 25. April (5.0 g eggs/day) Table 1. Experimental groups of catfish by 15. June 1987. Group Species Origin 86-(1+2) striped catfish pellets 86-3 Spotted catfish pellets 87-1 Striped catfish Dry pellets (Elite Plus 1.0) Food type S0dandet Wet Barent Sea Wet Faeroe Island

6 87-2 " " " Table 2. The specific growth rate (SGR) in three of the groups during May 1987. Group N %-growth SGR (%) Wt1-1gl Day W t2-i(g),---_---"d=a:;l;,lyt.-----lt=2-t=1--,(days=) 86-346 29.6 0.90 24.48237 31.7 265 28 87-120 140.2 3.13 0.27374 0.655102 28 87-287 151.0 3.29 0.40274 1.008102 28 200-------------------- 9 I/).c I/) ;;: -o o Z 150 100 50 8 7 6 5...... :::J -cu -- c.. E I- No. of fis Temperatl C 20 40 60 80 100120..... Age in [ 0.3 0.6 1.0 Figure 1. Temperature (OC) and number of survivals during startfeeding in group 87-1. Period fed with Skrettlng "Elite Perle" are indicated.

7 200----------------------9 IJ) J: IJ) -o o Z 150 100 50 8 7 6 5... -cu... - No. of fis E Temperatl I- C+-T-4 C 20 40 60 80 100 120...... 0.3... Artemia Age in [ 0.6... Figure 2. Temperature (OC) and numbers of survivals during startfeeding in group 87-1. Period fed Skretting "Elite Plus" and Artemia sauna nauplii are indicated. 1.0

8 COLLECTION OF WILD FISH SPRING-87 The collected fish have been divided into the following groups according to their weight (table 3). Most of the fishes greater than 3.0 Kg are to be put into a 2500 m3 (ca. 500 m 2) concrete outdoor basin. The fishes will be observed by underwater video-equipment and divers Table 3. Number of fishes in different size groups by the 12. June 1987. Group (Kg) 0.5-1.0 1.0-1.5 1.5-2.0 2.0-2.5 2.5-3.0 > 3.0 Number 13 41 36 26 23 110 ECONOMY The proj ect started 1. April 1987 with the second quarter as the main investment period. There has been a delay for about three mounts in the main investment post, the tanks. The table 4 gives an overview of the economical situation by the 12. June 1987. All numbers in Kroners (NKr.) Table 4. An economical overview by 12. June 1987. Post Used Budget (1987) Project-Ieader5000.00 15000.00 Overtime 60000.00 Traveling 0.00 40000.00 General Div. 2907.40 3084.50 70000.00 70000.00 Buying fish39323.64 Food 44.50 100000.00 25000.00 Data 65483.50 80000.00 Investments206484.13685000.00 Sum 322327.67 1.145000.00 SpeCification of investments Tanks equipments 78125.93 300000.00 Food auto 9040.80 35000.00 Pumps 0.00 15000.00 Div. build. 0.00 35000.00 Data 50000.00 50000.00 Div. Lab. 34062.50 100000.00 Video equip.29909.90 100000.00

Alarm sys. 0.00 50000.00 Sum 206484.13 685000.00 9

1 0 REPORTS; NEWSPAPERARTICLE; RADIOPROGRAM Agderposten 2/2-87. Fl0devigen nye oppdrettsfisk Agderposten 9/3-87. Steinbit hos gynekologen A-Magasinet Nr. 3/87: side 20. Nye husdyr i havbruket Fedrelandsvennen 29/4-87. Steinbit -ny. lovende oppdrettsfisk: Selges ikke pa trynefaktoren. Fiskaren 29/4-87. "Er jeg gravid doktor?" Med fru Steinbit til gynekologen. Lillesandposten 30/4-87. Forskningsstasjon vii ha levende steinbit Nordisk Aquakulture Nr. 1/87: 12-13. Nye marine arter: Stygg som steinbit. NTB-reportasje (Mars/April). Steinbiten - den nye oppdrettsfisken (Publ. i en rekke av landets aviser. (b1.a. Nordlys. Sunnm0reposten. Fedrelandsvennen, Vart Land, Tiden) Varden 11/3-87. Krager0-steinbiten far sin "brudesuite" NRK radio PI "Kolumbus", 30 min. Kl. 1920 27/5-87. Moksness, E. og J. Gj0seter 1987. Progress Report 24/4-87. 3 pp.

1 1 APPENDIX : TERMINTATED GROUPS APPENDIX 1: The 85-3 group Materials During a cruise with R/V "G.O.Sars" from 20 August to 5 September 1985 in the Barent Sea, 35 live spotted catfish juveniles (A. minor) were caught. The juveniles were taken in the upper 60 m with a pelagical trawl towed with a speed of 3 nm. The salinity and temperature in the sampling area were around 33 0/00 and 7.5 0C respectively (Anon. 1985). The juveniles were transported to the laboratory at Fl0devigen Biological Station and dived into three groups: 85-1, 85-2 and 85-3. Of these three groups, the juveniles in 85-3 were the one with best growth. The experiment started 12 September 1985, defined as day O. Table 1 gives the corresponding dates to the number of days in experiment. The two groups, 85-1 and 85-2, were kept in tanks of 500 I during the experiment, while 85-3 was transferred from 500 I tank to a 2500 1 tank after 431 days (Table 2). The two groups, 85-1 and 85-2 were terminated after 207 (7/4-86) and 237 (7/5-86) days respectively. The remaining fishes in these two groups were transferred to a predator experiment, 86-1. The group 85-3 were terminated after 508 days (2/2-87), when a accident killed them all. The salinity were stable around 33 0/00 during the whole experimental period, while the temperature varied from 3.9 QC in the winter to 13.5 QC in the summer with a average of 8.8 QC in the whole period (Fig. 1). Results Growth The growth in length and wet weight are given figure 2, 3 and 4. Growth in relation to temperature are given in Fig. 5 and 6. The figures indicates reduced growth i the periods 175-250 and 350-450 days. There is no indication that this reduction in growth are related to temperature. Length/weight relationship is given in Fig. 7 with equation expressing the curve. Growth rate The %-growth curve of the fishes together with observed temperature are given in Fig. 8, while Figs. 9 and 10 gives the % growth together with observed average length and wet weight respectively. The figures indicates an rather high growth rate initially, then the growth rate dropped with decreasing

1 2 temperature. A later increase in temperature did not make the growth rate increase. Condition factor The observed average condition factor of the fishes together with observed temperature and average wet weight are given in Figs. 11 and 12 respectively. The figures indicates a low condition factor (below 0.95) in periods with slow growth. Feeding Table 3 gives the menu for the fishes in group 85-3. The composition of the wet pellets are also indicated. The amount of wet pellets fed the fishes are given in Fig. 13. There is no positive correlation between amount of wet pellets and the temperature. Figs. 14, 15, 16 and 17 gives the observed amount of wet pellets fed the fishes, the amount of wet pellets per fish fed together with the the average length and wet weight of the fishes. The figures indicates a positive correlation between the size of the fishes an the amount of food fed them. As indicated in Fig. 18, there is a also a positive correlation between amount of wet pellets per fish and the fishes growth rate. Table 4 indicates that the food factor (FC) of the spotted catfish might be below 2.0. The 85-1. 85-2 and 85-3 groups Numbers The survivals in the three groups are given in figure 19. Mortality was only observed to some extent in 85-1, while in 85-2 the numbers were reduced with almost 50 % over 200 days. All the juveniles died accidently, when the tank fell down. Average Length, wet weight, condition factor and %-growth are given in Fig. 20, 21, 22 and 23 respectively.

1 3 TABLES Table 1. Codesponding dates to number of days in experiment. Days in Experiment Date o 12/9-85 50 1/11-85 100 21/12-85 150 200 9/2-86 31/3-86 250 20/5-86 300 9/7-86 350 28/8-86 400 17/10-86 450 500 6/12-86 25/1-87 Table 2. Period of experiment (Days in experiment) the fishes spend in different tanks. Group 85-1 85-2 85-3 5001 1 0-207 0-237 0-431 431-508 Table 3. Type of food fed the fishes in different periods (days of experiment). Period o - 176 176-237 237-267 267-308 308-508 Food-type wet pellets dry pellets fish meat experimental wet pellets wet pellets * * Consisted mainly of macrell (- 48 %), Shrimps (- 24 %), "bindemiddel, Skrettlng 25 %" (- 29 %), vitamin E+ and vitamin C. Dry weight of the wet pellet around 50 %.

1 4 Table 4. Different calculated food-factor (Fe). Dry weight of fish - 20 % and of the wet pellets from 40 to 55 %. Average food-factor Period INDEX Real numbel s 30 % INDEX %- g rowth 308-333 2.7 3.32 2.33 l.8 24.8 333-362 2.4 36.05 25.33 17.3 1.37 362-390 l.83 2.78 l.95 l.02 13.1 390-418 l.79 / 418-445 2.75 8.07 5.65 4.44 9.86 445-480 3.75 3.63 2.54 2.72 44.8 480-508 2.75 5.19 3.64 2.86 24.73

1 5 FIGURES 14 e ::J 1ii... 12 6 10 0 - c.. E 8 6 4 2 0 100 200 300 400 500 600 Days in Experiment Figure l. The observed temperature in the experiments. E 45 40 35 30 25. :..- 0) c: 20 1 5 1 0 5 0 0 50 100 150 200 250 300 350 400 450 500 550 Days in Experiment Figure 2. Average length (cm) with standard deviation of fishes in 85-3.

1 6 El +-'.c C) '0) 3: +-' 1000 900 800 700 600 500 400 300 200 100 0 0 50 100 150 200 250 300 350 400 450 500 550 Days in Experiment Figure 3. Average wet weight (g) with standard deviation of fishes in 85-3. 50 1000 40 800 C) E 30 600 - (,) 1: C)..c -a- 'Qj Length (cm) -C) Wet Weight (g) r: Cl)...I 20 400 3:... 10 200-0 0 0 100 200 300 400 500 600 Figure 4. Combined average length and wet weight of fishes in 85-3.

1 7 14 50 12 40 00 10-30 E u ::l 8 - Temperature e..- C)... Length (cm) c.. 20 c E 6 I- 4 2 0 0 100 200 300 400 500 600 Figure 5. Temperature and average length (cm) of fishes in 85-3. 10 14 1000 12 800-0 0 10 -.9 -e 600..- ::l C)..- 8 "a; Temperature e c.. E 6 Gi s: I- 4 2 0 0 100 200 300 400 500 600 400 s:... Wet Weight (g) Figure 6. Temperature and average wet weight (g) of fishes in 85-3. 200

1 8 1200 y = 3.9924 * 10"(0.0588x) R = 0.97 Y = -87.1711 + 15.41 09x - 0.7874x"2 + 0.022x"3 R = 0.99 1000 -Cl 800 --..c Cl 'Qj 600 3: li 400 3: 200 0 0 10 20 30 40 50 Length (cm) Figure 7. Length/wet weight relationship of fishes in 85-3. 14 100 90 12 80 70 u -0 10 60..c - ::I 50... 8 Temperature e 40 e c.. 1 --- %-growth E 30 6 I- 20 4 10 0 2-10 0 100 200 300 400 500 600 Days in Experiment Figure 8. Temperature and % growth of fishes in 85-3.

1 9 50 200 40 100 E 30.c u.c -a- Length (cm) -... C) %-growth 20 fj»... c j '<fl. 0 10 0-100 0 100 200 300 400 500 600 Figure 9. Average length (cm) and % growth of fishes in 85-3. 1000 ----------------------200-600 -.c C) 400 4) -C) 100 :s: 200 0.c -a- Wet Weight (g) 2 1... %-growth 800 o -100 o 100 200 300 400 500 600 Figure 10. Average wet weight (g) and % growth of fishes in 85-3.

20 14 1.2 12 1.1-0 0 10 - I!! :::J 8 1.0 u: Temperature e 0 Cl)... C.F. c.. E 6 Cl) I- 0.9 4 2 0.8 0 100 200 300 400 500 600 Figure 11. Temperature and average condition factor (C.F.) of fishes in 85-3. 1000..,.------------...,...1.2 800 1.1-9 -..c: C'I di == 600 400 200 1.0 0.9 u: o -a- Wet Weight (g)... C.F. o 0.8 o 100 200 300 400 500 600 Figure 12. Average wet weight. (g) and average condition factor (C.F.) of fishes in 85-3.

21 14 ----------------------400 12 300 -() 0 10 - -.9 III ::l ]! 8 200 Temperature -e Qj c....0- Wet Pellets (g) c.. E 6 I- 100 4 4i 3: 2 4-------0 0 100 200 300 400 500 600 Figure 13. Temperature and amount of wet pellets (g) fed the fishes in 85-3. 400---------------------- 44 -Cl -III ]! Qj Il. 4i 3: 300 200 100 42 40 -E (,) 38 -.....c..- Wet Pellets (g) Cl Length (cm) 36 34 32 c..j 04--------------+ 30 300 400 500 Figure 14. Average length (cm) and amount of wet pellets fed the fishes in 85-3.

22 40 --------------------30 - E..c -Cl c: j 36 34 20 10... Length (cm) W.PelletlFish 38 32 30 -----T--T-O 300 350 400 450 500 Days in Experiment Figure 15. Average length (cm) and amount of wet pellets/fish fed the fishes in 85-3. 400-----------------------r 1000 800 300 - -Cl -(J) 200 Qj a. 100 600 - -..c 400 200 Cl Wet Pellets (g)... Wet Weight (g) G) 3: O---U-----------+ 0 300 400 500 Days in Experiment Figure 16. Average wet weight (g) and amount of wet pellets fed the fishes in 85-3.

23 800 ----------------------30 -.9...-.r:::: Cl '0) 3: Qj 3: 600 500 400 20 10.. Wet Weight (g) W.PelletlFish 700 300 --'--r--t-----r0 300 350 400 450 500 Figure 17. Average wet weight (g) and amount of wet pellets/fish fed the fishes in 85-3. 400------------------------r 100 90 80 300 70 -Cl 60 -III ]i 50 200 Qi c. 40 Qj 30 3: 100 20 10 0 o-----------+ -10 300 400 500 600.r:::: i e t(> '#. Wet Pellets (g).. %-growth Figure 18. Amount of wet pellets (g) fed the fishes in 85-3 and their %-growth.

24 16 14 12 -Ill- # 85-1.0 E... #85-2 ::s 10 -M- #85-3 z 8 6 0 100 200 300 400 500 600 Figure 19. Numbers of survivals in the three groups of spotted catfish; 85-1, 85-2 and 85-3., 25 20 -E 15 () -.c... Cl c..j 10 -Ill- Length 85-1... Length 85-2 -a- Length 85-3 Figure 20. catfish. o 25 50 75 100125150175200225250 Average length (cm) in the three groups of spotted

25 150 -Cl - 100.c -a- Weight 85-1 Cl '... Weight 85-2 -a- Weight 85-3 3: 50 O-r-T-r-r o 255075100125150175200225250 Figure 21. Average wet weight (g) of the fishes in the three groups of spotted catfish. 1.2 1.1 d 1.0 -... 0 U -a- C.F.85-1 If 0.9... C.F.85-2 c 0 :B 0.8 "C c 0 u 0.7 -a- C.F.85-3 0.6 0 100 200 300 400 500 600 Figure 22. Average condition factor (C.F.) in the three groups of spotted catfish.

26 160 140 120 100..c: i 80 e (!) 60 I -Ill- %-Gr. 85-1 0 40 20 0-20 0 100 200 300 400 500 600 -+ %-Gr. 85-2 -11- %-Gr. 85-3 Days in Experiment Figure 23. %-growth (%-gr.) in the three groups of spotted catfish.

27 APPENDIX 2: THE 86-2 GROUP The fishes in 86-2 were collected in April/May 1986 and came from southern Norway. Table 5 gives the corresponding date to the numbers of days in experiment. RESULTS The fishes were kept for the whole experimental period (280 days) in a tank of 5000 I (3 m in diameter), (Table 6) and fed mainly wet pellets (Moksness og Gj0seter 1987) (Table 7). The obtain food factor (FC) was rather height indicating that to much food were fed the group (Table 8). The %-growth was rather low indicating slow average growth in the group, but the results are also disturbed by a high mortality (fig. 24) in the group, mainly as results of an accident, as the tank was emptied for water one night. In the group as a whole a low condition factor (CF) (below 0.9) were observed during the experimental period (Fig. 34 and 35). Dead fishes in the tank were observed with a average CF of 0.83 (table 9) Table 5. Corresponding dates to days in experiment i 86-2. riment Date 6/5-86 25/6-86 14/8-86 3/10-86 22/11-86 11/1-87 Table 6. Days in and size of tank. Group 86-2 50001..1 0-268 Table 7. Different food types for 86-2 (testing) Period 0-73 73-268 Food e Macrell meat/wet pellets wet pellets (as for 85-groups)

28

29 Table 8. food-factor (FC) of fishes in 86-2. Period 0-31 31-72 72-157 4.2 157-217 2.31 217-268 11.42 Averafle INDE k %-Q'rowth - 14.86 3.82 2.6 food -factor Total Fr 30 % - 10.4 INDEX 8.92 11.83 Table 9. Condition factor (CF) observed on some dead fishes in 86-2. Number CF 1 0.42 2 0.79 3 0.81 4 0.82 5 0.90 6 0.96 7 0.96 8 1.00 Average 0.83 Data from "86-2.alle data" 12 60 10 50 U 0 8 40 2! I!! :J G) Temp e 6 30 -..Q G) E c.. :J Antall E z G) 4 20 I- 2 10 0 0 0 100 200 300 Fig. 24. Observed temperature (OC) and numbers of survivals in 86-2.

30 70 65 60 55 50 45 E 40.c +-' 35 Cl c::...j i f 1 f- 1 30 25 20 15 1 0 5 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 days in Experiment Figure 25. Average total length (cm) with Standard deviation (SD) of fishes in 86-2. 3000 2500 -- - 2000...! 1500 er 1000 _..L. -- ) 500 O+-'-I.-..-r-r-r-I-+ 20 40 60 80 100120140160180200220240260280 days in Experiment Fig. 26. Average wet weight (g) with standard deviation (SD) of fishes in 86-2.

31 60------------------------r1900 59 1800 E E (,) (,) - - 58 1700 -Ill-.c.c Lenght (cm) Cl Cl... c Weight (cm) Q;.3 3: 57 1600 56 -t--'"'"""t"""----r-----r-----,-----.----+ 1500 o 100 200 300 Fig. 27. Combined average total length (cm) and average wet weight (g) of fishes in 86-2. 12 ------------------60 10 G)... 8 ::J 10... 6 G) Q. E 4 2 59 -E 58 -.c Cl c G)..J 57 Temp.... Lenght (cm) 0 ""T"""----r---------56 0 100 200 300 Fig. 28. Temperature (OC) and average total length (cm) of fishes in 86-2.

32 12 -----------'"'T" 1900 2! 10 8 ::l -e G) 6 c.. E G) I- 4 2 1800 1700-1600 - E Temp...r:::: Cl 'G) ==... Weight (cm) 0 4-----------1500 0 100 200 300 Fig. 29. Average wet weight (g) and temperature in 86-2. y = 65.8395 * 10"(0.0239x) R = 0.96 Y = - 3820.7529 + 217.9886x - 4.1276x"2 + 0.0343x"3 R = 0.96 4000-------------------- 3000 -Cl -..r:::: 2000 Cl 1000 O----------- 30 40 50 60 70 80 Length (cm) Fig. 30. Length/weight relationship of fishes in 86-2.

33 12 20 10 :::J - i 8....c e 6 0 Temp. e c..... %-growth E fi. 4-10 2 I- 0-20 0 100 200 300 Days in Experiment Fig. 31. Temperature and %-growth of fishes in 86-2. 10 60------------------------20 59 10 -E.c to) - i 58 0 -Ille Lenght (cm).c Cl... c: fi...j 57-10 %-growth 56-----r--------r---+-20 o 100 200 300 Days in Experiment Fig. 32. Average total length and %-growth of fishes in 86-2.

34 1900.---------------,-20 1800 10 - E ()..c -... i 1700 0 -Ille Weight (cm)..c C) Ij»... %-growth '# 1600-10 1500 -t---w--"""t""---.----r---.----+ -20 o 100 200 300 Fig. 33. Average wet weight (g) and %-growth of fishes in 86-2..-------r-:--:---------r 1.0 0.9 u.: o Temp. -0- C.F. +---w---r---r---.-----.---4-0.8 100 200 300 Days In Exprlment Fig. 34. Temperature and average condition factor (CF) of fishes in 86-2.

35 1900,...----------- 1.0 1800 - E... 1700 0.9 u: -Go.c Weight (cm) cj Cl... C.F. '0) 3: 1600 1500 -+--""T""---,..---.----,...---r- 0.8 o 100 200 300 Fig. 35. Average wet weight (g) and average condition factor (CF) of fishes in 86-2. 12 10 ----------3000 :::J 8 iu... 6 a.. E 4 2 2000 a.. 1000 Temp.... Wet pellets (g) 0 --""T""------r0 0 100 200 300 Fig. 36. Temperature and amount of wet pellets (g) fed fishes in 86-2.

36 3000----------------------60 59 c; 2000 - t/i E (.) 58 -a- Wet pellets (g) Q;.c - c.. C)... c Lenght (cm) - 1000 j 3: 57 0-1---r---r--56 o 100 200 300 Fig. 37. Average total length (cm) and amount of wet pellets (g) fed fishes in 86-2. 60---------------------- 60 59 E (.) -.c 58 C) c...j 57 50 40.c t/i 30... -Go Lenght (cm) Q; W.Pelletlfish c.. 20 ;: 10 0 o 100 200 300 Fig. 38. Average total length (cm) and amount of wet pellets/fish (g) fed the fishes in 86-2.

37 3000..,...-------------.-1900 1800 2000 - - C) I/) E ]i 1700 Qj Q. C)... l) 3: - -Go.J: 1000 1600 Wet pellets (g) Weight (cm) o +--""T"""--r--"""T""-r.:&.,=""_= 'I.:L----+ 1500 o 100 200 300 Fig. 39. Average wet weight (g) and amount of wet pellets (g) fed the fishes in 86-2. 1900..,...-------------.- 60 1800 -E -- u 1700.J: C) ' 3: 1600 50 40.J: I/) 5 30.!! -Go Weight (cm) Qj... W.PelleVfish Q. 20 ;: 10 1500-""T"""--"""T""-- 0 o 100 200 300 Fig. 40. Average wet weight (g) and amount of wet pellets/fish (g) fed fishes in 86-2.

38 20------------------------r 60 10-10 50 40 or. 1/1 :;:: 30-0- %-growth c... W.PelleVfish 20 := 10-20-----r-------T-- 0 o 100 200 300 Fig. 41. Amount of wet pellets (g) fed fishes in 86-2 and their % growth.

39 Appendix 3: The 86-3 group The group consisted of 7 spotted catfish, collected during cruises august/september 1986 with R/V "G.O. Sars" and R/V "Eldjarn" in the Barent Sea (Anon. 1986). The experiment started 6/8-86, defined as day 0 in the experiment. All seven fishes died accidently, when several tanks collapsed in January 1987. The seven fishes -s life history in the laboratory are given in table 10. The fishes had a SGR for the whole experimental period of 1.75 %/day. Table 10. The life history in the laboratory of fishes in 86-3. Days in EX:Qeriment Length {cm} weight {g} CF %- growth SGR 0 8.97 6.9 0.95 27 11.79 17.0 1.03 145.5 3.3 56 25.2 47.8 1.4 83 36.3 44.0 1.4 118 18.5 66.7 0.99 75.5 1.6 146 20.8 89.4 0.98 40.5 1.2 14 12... ::::J 10 -e c. E 8 I- 6 4 0 100 200 Figure 42. The observed temperature in experiment 86-3.

40 140 y = 1.1843 * 10"(0.0914x) R = 0.99 Y = 5.867-1.549x + 0.1285x"2 + 0.0066x"3 R = 0.99 120 100 -C) --..c: C) ' 3: 80 60 40 20 0 o 10 20 30 Length (cm) Figure 43. Length/weight relationship of fishes in 86-3. References Anon. 1985. Preliminary report of the international O-group fish survey in the Barent Sea and adjacent waters in August-September 1985. ICES CM 1985/G:75 : 1-27. Anon. 1986. Preliminary report of the international O-group fish survey in the Barent Sea and adjacent waters in August-September 1986. ICES CM 1986/G:78 : 1-27. Moksness, E. og J. Gj0seter 1987. Arsrapport 1986 pa prosjektet "Oppdrett av Steinbit" til BPNorge A/S.