Growth, survival and food conversion ratio (FCR) of Cyprinus carpio in cages at

different stocking density were studied in Kaptai lake. Fingerlings of common carp

(12.47 ± 4.29 g) were stocked at 25/m2

, 50/m2 and 75/m2 each with replication in six

floating net cages each of Sm x Sm x 4m and reared for 240 days. The growth rate was

inversely related to the stocking density with the mean weights of 325.5 ± 11.74 g,

268.99± 8.44 g and 167.0 ± 11.66 g at low, medium and high densities, respectively. At

harvest, standing crop biomass averaged 7 .82, 12.83 and 11.58 kg with the survival of

98.9%, 97.6% and 94.4% and food conversion ratios of 4.51, 3.82 and 4.21 for the above

three densities, respectively. Weight gain and production at density 25 fish/m 2 were

significantly different (p< 0.01) from other two densities. Water quality was not affected

in the cages having different stocking densities

Ahmed, K.K.

Haque, M.K.I.

Paul, S.K.

Saha, S.B.

Aquatic Commons

2Bangladeshf. Fish Res., 6(2), 2002:135-140 
Effect of stocking density on the production of common carp 
( Cyprinus carpio Lin.) in cages at Kaptai lake, Bangladesh 
K.K. Ahmed, M.K.I. Haque*'1, S.K. Pauf and S.B. Saha3 
Bangladesh Fisheries Research Institute, Riverine Sub-station, Rangamati 4500, Bangladesh 
1 Bangladesh Fisheries Research Institute, Freshwater Station, Mymensingh 
2 13/417 Liverpool Road, Ashfield, Sydney, Post Code-2131, Australia. 
3 Bangladesh Fisheries Research Institute, Marine Fisheries and Technology Station, Cox,s Bazar 
*Corresponding author 
Abstract 
Growth, survival and food conversion ratio (FCR) of Cyprinus carpio m cages at 
different stocking density were studied in Kaptai lake. Fingerlings of common carp 
(12.47 ± 4.29 g) were stocked at 25/m2 , 50/m2 and 75/m2 each with replication in six 
floating net cages each of Sm x Sm x 4m and reared for 240 days. The growth rate was 
inversely related to the stocking density with the mean weights of 325.5 ± 11.74 g, 
268.99± 8.44 g and 167.0 ± 11.66 gat low, medium and high densities, respectively. At 
harvest, standing crop biomass averaged 7 .82, 12.83 and 11.58 kg with the survival of 
98.9%, 97.6% and 94.4% and food conversion ratios of 4.51, 3.82 and 4.21 for the above 
three densities, respectively. Weight gain and production at density 25 fish/m2 were 
significantly diffe~ent (p< 0.01) from other two densities. Water quality was not affected 
in the cages having different stocking densities. 
Key words: Stocking density, Common carp, Kapai lake 
Introduction 
Kaptai reservoir with an average surface area of 58,300 ha constitute a largest man-
made lake in Bangladesh and also in the whole of South East Asia ( Fernando 1980 ). 
However, it was constructed by damming the Karnafuli river primarily for hydroelectric 
power generation and as well as for navigation, flood control and irrigation purposes, but 
its contribution to the fish production can not be neglected. Even this potentiality could 
be increased several fold by adopting cage culture technique. Additional advantages of 
this technique are that it could avoid the tedious task of aquatic weeds and predator 
control. Today in many countries fish production in cages has extensively developed by 
the improvement of stocking rates, feeding methods and selection of species ( Sodikin 
1977 ). The present study on monoculture of common carp in cages were undertaken to 
determine a suitable stocking rate by administering different indigenous components 
which can yield optimum growth in reasonably short period. The dearth of published 
information in this line has been presented by J angkuru and Djajadiredja (1979), Backiel 
et al. (1984), Haque et al. (1984) and Costa-Pierce et al (1989). 
K.K. Ahmed et al. 
Material and methods 
Six floating net cages each of 5m x 5m x 4m have been constructed with knotless 
polyester net (meshing 10.5 mm) and fitted to the inner side of a bamboo frame. The 
whole structure was kept afloat by means of empty plastic oil drum fastened at 
reasonable distance by synthetic ropes. A separate synthetic net to prevent the escape of 
the fish closed upper side of each net. Two bamboo made feeding baskets were hung 
loosely 1m below the surface water in each cage with the help of nylon twine. Thereafter, 
all these cages were stocked with fishes of 12.47±4.29g in average body weight at the rate 
of 25 (cage 1 and 2 ), 50 (cage 3 and 4) and 75 (cage 5 and 6 ) fish/ m 2 and continued 
rearing up to 240 days to observe their growth rate. 
Supplementary feed composed of 30.2% dietary protein; extracted from 20% fish 
meal, 20% rice bran, 40% mustard oil cake and 20% wheat bran was fed to the fish at 5% 
body weight twice daily. After each 30 days interval, 20% fish from each cage were 
caught, measured and weighed as a group. Subsequently feeding rates were adjusted 
according to new biomass. At the end of 240 days of rearing all the fishes were harvested, 
counted and weighed . 
Consequently, water temperature, dissolved oxygen, free carbondioxide, pH and 
total alkalinity of water within the cages were measured fortnightly between 9 to 10 am 
by using the centigrade thermometer, winkler method (APHA 1981 ), phenolphthalein 
indicator method, lovibond disk comparator and titrimetric method, respectively. 
Results and discussion 
Data for stocking, survival and growth ratios as well as the food conversion ratio ( 
FCR) are given in Table 1. Growth patterns are shown in Fig. 1. The survival rates were 
98.9%, 97.6% and 94.4% at low, medium and high densities, respectively. 
Simultaneously, within 240 days the mean weight of C carpio attained 325.5± 11.74 g 
with an average daily growth of 1.3 g fish/ day, 268.99 ± 8.44 g with an average daily 
growth 1.1 g fish/day, and 167.0 ± 11.66 g with an average daily growth of0.6 g fish/day 
i.e., the total increase in weight was 2550%, 2057% and 1239 % in the above three 
densities, respectively. These in term of yields in three stocking rates were 7.82 kg /m2 , 
12.83 kg/m2 and 11.58 kg/m2 (Table 1). FCR ratios in three sets of replicated cages with 
increasing densities were 4.51, 3.82 and 4.21, respectively. 
Statistical analysis about the individual growth also support in favour of 25 fish/m2 ( 
p< 0.01 ) than that of 50 fish/m2 and 75 fish/m2• This is probably due to low stocking 
rate, sufficient natural food and space as well as less competition prevailed in the 
condition. Lembi et ai. (1968) and Kilambi et a1. (1977) reported that decreasing in 
individual growth with increasing stocking density might be due to heavy competition 
during feeding at densely populated cages. 
Again, the total production of fish at the end of the experimental period was 
maximum in 50 fish/m2 cages (Table 1) and next to this was in 75 fish/m2 cages. 
Production at 25 fish/m2 was significantly different (p < 0.01) from other two densities. 
136 
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Table 1. Growth performance of common carp (Cyprinus cmpio) within 240 days of experiment at three stocking densities of Kaptai lake 
Cage No of fish Mean weight Mean weight Net gain Total increase Average daily Survival rate FCR Yield/month 
no. stocked in (g) at in (g) at (g) in weight (%) growth (g) (%) (kg) 
stocking harvest fish/ ay 
----
500 12.47±4.29 332.0±13.30 319.53A 2562 1.331 98.2 4.83 7.988A 
2 500 12.47±4.29 319.0±10.18 306.53A 2458 1.277 99.6 4.20 7.663A 
3 1000 12.47±4.29 261.9±8.37 249.43BC 2000 1.039 97.8 3.55 12.471BC 
4 1000 12.47±4.29 276.09±8.04 263.62BC 2114 1.098 97.4 4.09 13.181BC 
5 1500 12.47±4.29 173.09±10.82 160.62BD 1288 0.669 94.7 4.32 12.046BC 
6 1500 12.47±4.29 160.91±12.50 l48.44BD 1190 0.618 94.0 4.11 11.113BC 
Value representing same superscript vertically do not differ significantly ( P< 0.01 ). 
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K.K. Ahmed et aL 
Dimitrov (1976) said that the best production of carps in net cages achieved at higher 
stocking densities (80 and 50 fish/m2) than the lower one (25 fish/m 2). Backiel and Le 
Cren (1967) found that the growth and production of fish are to certain extent, 
dependent on the population density. Powell (1972) mentioned the harmful effects of at 
higher stocking density on the culture of fish were reduction of growth rate, increase of 
food conversion ratio and lowering of survival rate. Higher survival rate in the present 
study was obtained in low stocking density cages. 
350 
300 
3 250 
~ 200 
~ 150 
OJ) 
"' ~ 100 ~ 
50 
0 
-::1(- Density 75 
-•- Density 50 
-<>-Density 25 
Fig. 1. Growth curves of Cyprinu.1· carpio stocked at three different densities in cage 
at Kaptai lake. 
An average daily growth at three densities might be compared with the growth of 1.4 
g for 25 g 0. spiiurusniger(Gunther and Haller 1974), 1.0-3.0 g for 50 g tilapia (Marek 
1975 ), 0.85 g for 20 g tilapia (Hastings 1973) and 0.58 g for 25 g Oreocromis ni}oticus 
in ponds (Miller 1976). 
Costa-Pierce et al (1989) reported the mean weight of common carp attained 500g 
within 3-4 months with an av_erage production of 12.83 kg/m2 at density of 50 fish/m2 
also support in term of yield for medium density. They also found a very healthy 
condition offis4 with 97.6% survival rate. The water quality had not deteriorated and a 
higher production was possible by increasing the stocking density up to 50 fish/m2 • 
Different stocking densities had influenced the food conversion efficiencies (Table 1). 
The FCR ratio varies from species to species, for different types of foods and in different 
environments. For 0. nilodcus, Hepher and Pruginin (1982) reported FCR values of 3.6 
for ground nut cake, 4.8 for cotton seed cake, 1.8 to 6.5 for pelleted chicken feed plus 
10% fresh fish, 12.6 for brewery waste and 18.9 for cotton seed crush. Shell (1968) 
reported an FCR value of 2.31 for 0. niloticus feed consisting 25% dietary protein rich 
pelleted feed. Allison et al. (1976) reported food conversion ratios of 1.56, 1.40, 1.27 and 
0. 92 in four concrete tanks for 0. aureus stocked at different densities and found that 
higher rates of stocking affected the water quality and food conversion efficiency. 
138 
Stocking density of common carp in cages 
Monthly average water temperature in cages ranged from 22.5 (January) to 31.0 
(April). Water pH ranged from 7.5 to 8.5. A pH of 7-8 has been recommended as the 
best pH for fish culture (Huet 1972). Average morning concentrations of DO ranged 
from 5.8 to 8.2 mg /1 ( Fig. 2 ) which is very suitable for any aquatic life (Boyd 1979). 
Free C0 2 ranged from 4.4 to 6.0 mg/1 and total alkalinity from 44.0 to 56.0 mg/1
1 (Fig. 
2 ). The alkalinity of water of cages does not have a direct effect on fish but an alkalinity 
between 30 and 200 mg/1 1 has been recommended for freshwater fish culture (Stickney 
1979 ). Therefore, water temperature, pH, DO, free CO 2 and total alkalinity were within 
optimum ranges for carp growth. Water quality was not affected in the cages having 
different stocking densities (Fig: 2 ). The data suggest that rearing of common carp at a 
density more then 50/m2 will not be effective at the management level described in the 
present study. 
References 
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carbondioxide If 
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Temperature 
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I 
Fig. 2. Water temperature). pH dissol"'d o"-ygen, free carbondioxide and total 
alkalinity of cage 'mter at Kaptai lake. 
Allison, R, R Smitherman and 0. Cabrero, 1976. Effects of high density culture and form of feed 
on reproduction and yield of Tilapia aurea. In: Advances in Aquaculture (eds. T.V.R. pillay 
and W.A. Dill). Fishing News Books Ltd, Farnham, Surrey. pp. 168-170. 
American Public Health Association, 1981. Standard Methods for the Examination of Water and 
Waste- water. 15th ed. American Public Health Association, New York. 1134 pp. 
Backiel, T., B. Kokurewicz and A. Ogorzalek, 1984. High incidence of skeletal anomalies in carp, 
Cyprinus carpio, reared in cages in flowing water. Aquaculture, 43: 369- 380. 
Backiel, T. and E.D. Le Cren, 1967. Some density relationships for fish population parameters. In: 
The Biological Basis of Freshwater Fish Production (ed. S. D. Gerking). Blackwell Scientific 
Publications, Oxford and Edinburgh. pp. 261-293. 
Boyd, C. E., 1979. Water Quality in Warmwater Fish Ponds. University of Alabame Press, Auburn. 
139 
K.K. Ahmed et al. 
Costa-Pierce, B.A., A.S. Rusydi and G.W. Atmadja, 1989. Culture of common carp in floating net 
cages. ICLARM Education Series 7, Institute of Ecology, Indonesian State Electric Company 
(IOE UNP AD-PLN ), Ban dung Indonesia and ICLARM, Manila Philippines. 42 pp. 
Dimitrov, M. ,1976 Carp culture in net cages, FAO. Aquacult. Bull, 8 (1): 8 pp. 
Fernando, C.H., 1980. The fishery potential of man made lakes in South East Asia and some 
strategies for its optimization. In: BIOTROP Anniversary Publication, Bogor, BIOTROP, pp. 
25-38 
Haller RD., 1974. Rehabilitation of a Limestone Quarry. Report of an environmental experiment. 
Bamburi Portland Cement Co. Ltd ., Mombasa. 
Haque , M.M., A.K.M. Aminul Haque, M. Aminul Islam and G.U. Ahmed, 1984. Effect of 
stocking density on the survival and growth of Cyprinus carpio (Linnaeus ) cultured in 
floating Ponds. Bangladesh J Agn1 Sci. 11(2): 175-179. 
Hastings, W.H., 1973. Regional project on research and fisheries development ( Cameroon 
Central African Republic-Gabon-Congo Peoples Rep.). Experience related to the preparation 
offish feed and their feeding FAO Project Rep. FAO -FI -DP /RAF 66/054/1.24 pp. 
Hepher, B. andY. Pruginin, 1982. Tilapia culture in ponds under controlled conditions. In: The 
Biology and Culture of Tilapias (eds. R.S.V. Pullin and R.H. Lowe-Me Connell). ICLARM, 
Manila. pp. 185-204. 
Huet M., 1972. Textbook of Fish Culture. Breeding and Cultivation of Fish. Fishing News Books 
Ltd., Farnham, Surrey. 
Jangkuru, A. and R. Djajadiredja, 1979. Common carp in floating net cage culture. In: Proc. Int. 
Workshop on Pen and Cage Culture of Fish, Tigbauan, Iloilo, Philippines. Feb. 11-22, 1979 
SEAFDEC, Philippines. pp. 55-60. 
Kilambi, R.V., J.C. Adams, A.V. Brown and W.A. Wickizer, 1977. Effects of stocking density and 
cage size on growth feed conversion and production of rainbow trout and channel catfish. 
Frog. Fish. Culr., 39(2): 62-66. 
Lembi, C.A., B.G. Ritenour, E.M. !version and E.C. Forsa, 1968. The effects of vegetation removal 
by grass carp on water chemistry and phytoplankton in Indian ponds. Trans. Am. Fish. Soc.) 
107: 161-171. 
Marek, M., 1975. Revision of supplementary feeding tables for pond fish. Bamidgeh; 27: 57-64. 
Miller, J.W., 1976. Fertilization and feeding practices in warmwater pond fish culture in Africa . 
CIFA Technical Paper, 4: 512-541. 
Powell, M. R., 1972. Cage and race way culture of stripped bass in brackish water in Alabama. 
Proc. 26 Ann. Conf. South East Assoc. Game Fish Comm. pp. 553-565. 
Shell, E. W., 1968. Mono-Sex culture of male Tilapia nilorica (Linnaeus) in ponds stocked at three 
rates F AO Fisheries Report. 44: 353-356. 
Sodikin, 1977. Fish cage culture in Indonesia, construction and management. Technical Report of 
Workshop on Aquaculture Engineering, Vol. H., SFAFDEC Aquaculture Department 
Facilities Tigbauan, Iloilo, Philippines, 3: 353 -357. 
Stickney, R.R., 1979. Principles of warm water Aquaculture, John Wiley & Sons, New York. 
(Manuscript received 17 October 2001) 


Effect of stocking density on the production of common carp

(Cyprinus carpio Lin.) in cages at Kaptai lake, Bangladesh

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Effect of stocking density on the production of common carp (Cyprinus carpio Lin.) in cages at Kaptai lake, Bangladesh

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