Jana, B. B. and Chakrabarti, R. 1988. Some factors determining the feeding optima in carp fingerlings. Archiev für Hydrobiologie 113: 121-131.

The feeding optima and feeding time were examined in different species of carp (Catla catla, Cirrhinus mrigala, Cyprinus carpio) and tilapia (Oreochromis mossambicus) fingerlings under normal light and dark conditions. The feeding optima in different species varied by a factor of 2.8 (31.25 to 87.5 mg individual^-1 day^-1) depending upon the size of the test fingerlings. The uptake rate was more than 80% higher in common carp than in tilapia of similar body weight. The feeding level in the dark was reduced by 12 to 25% than under normal light. Exposure of fish to artificial light caused 9 and 49% enhanced grazing over the control during the day and night experiments, respectively. The feeding activity in common carp was more intensified (32%) in the morning (9.00 a.m.) than in the remaining part of the day.

Jana, B. B. and Chakrabarti, R. 1990. Exogenous introduction of live plankton -a better approach to carp growth than the direct manure system. The Progressive Fish Culturist 52: 252-260. 

The growth of four species of carp-catla (Calla catla), mrigal (Cirrhinus mrigala); common carp (Cyprinus carpio), and rohu (Labeo rohita) was compared among three feeding schemes: (1) exogenous introduction of zooplankton, (2) fertilization with manure, and (3) a control system with addition of boiled rice and mustard oil cake. Growth or fish was measured after 90 d in four separate tests conducted during September 1986-June 1987. Generally, frequency distributions of weight groups of fishes at harvest were skewed toward larger fish in the live food system and toward smaller fish in the control system. The instantaneous growth and net weight gain of fish were significantly higher in the live-food system than in the manured or control system. The better growth in the live-food system was attributed to a greater abundance of plankton and better water quality expressed in terms of lower values of chemical oxygen demand and higher concentrations of dissolved oxygen.

 

Jana, B. B. and Chakrabarti, R. 1990. Comparison of plankton intake by Indian carp fingerlings. Journal of Applied Ichthyology 6: 1-13.

The influence of different culture systems on the amount of plankton consumed by fingerlings of three carp species (Labeo rohita, Catla catla and Cirrhinus mrigala) was examined in outdoor culture tanks during a 90 days growing period. The fish were raised under two basically different feeding conditions: (a) fed with alIochthonous live plankton; (b) fed with plankton grown autochthonously in the fish growing tanks fertilized with manures. Both feeding regimes were compared with control groups. It was found that the plankton intake for carp held in the live food system was significantly higher than the manured and control systems. Related to maximum intake, maximum abundance of plankton in the live food system was a consequence of improved water quality expressed in terms of lower values of BOD and COD and higher values of DO and pH; this was conducive to fast reproduction of some of the zooplankton which constituted the major food items for the test carp, as well as to the regular exogenous introduction of live plankton. The ingestion of plankton was found to be related to carp body weight raised to the power b. The exponent b ranged from 0.29 to 0.93 during the 90-day growing period.

Chakrabarti, R. and Jana, B. B. 1990. Food preferences and selection by common carp (Cyprinus carpio) fry under different feeding regimes. Journal of Applied Ichthyology 6: 223-230. 

Food preferences of common carp fry were investigated in relation to qualitative and quantitative abundance of plankton in five culture systems (live food system, manured system, exchanged manured system, intermediate system and control system), which differ in management protocols. While phytoplankton was strongly avoided, as evident in the electivity index, cladocerans constituted an important source of natural food for common carp fry held in all five culture systems. There was a positive selection of cladocerans in the manured system as well as rotifers in the live food system, although the environment was dominated by copepods and cladocerans, respectively. While in all the culture systems there was a gradual rise in the relative ab­­­­­­­­­­­­­undance of copepods, cladocerans tended to decline in relative abundance in the diet of older common carp held in the manured system.

Chakrabarti, R. and Jana, B. B. 1991. Growth induction of common carp (Cyprinus carpio L.) as a function of plankton density and improve water quality. Aquaculture and Fisheries Management 22: 295 -307.

One hundred and ninety-eight fry of common carp, Cyprinus carpio L., were reared in outdoor tanks containing 9580 l of water under five management schemes -separate live-food system (LF), intermediate system (I), static manured system (M), manured system with water exchange (EM) and supplementary food system (SF) in triplicate for a growing period of 90 days. Examination of frequency distribution of different weight groups of fishes at the time of harvest showed a maximum proportion of larger and smaller fishes in the live-food and supplementary food system, respectively. Maximum growth and production of common carp in the LF treatment was the consequence of greater abundance of plankton food and improvement of water quality expressed in terms of higher values of pH and DO and lower values of COD and BOD.

Chakrabarti, R. and Jana, B. B. 1991. Plankton intake as a function of body weight by common carp fry in different feeding conditions. Aquaculture 93: 21-34. 

Plankton intake by common carp fry was investigated in relation to composition and abundance of plankton as well as water quality in five culture systems: live-food system (LFS), manured system (MS), exchanged manured system (EMS), intermediate system (IS), and reference control system (CS). The amount of plankton consumed by the common carp fry tended to rise gradually with in- crease in average body weight of carp held in all five culture systems. At a given time, the plankton intake for LFS was significantly higher than for the remaining four systems. Related to maximum intake, the maximum concentration of plankton in the live-food system was a consequence of improved water quality. Food consumption varied as a function of W^b, and estimates of the power b ranged from 0.479 to 0.864 in relation to culture systems and from 0.033 to 0.908 among age groups.

Chakrabarti, R. and Jana, B. B. 1992. Effects of different levels of exogenously introduced plankton on growth of common carp reared under favourable water quality. Aquaculture 103: 331-339.

One hundred ninety eight fry of common carp were placed into each of nine outdoor tanks (9580 I) and subjected to three different levels (dry weight) of exogenously introduced plankton, viz. 134 mg l^-1 (normal), 264 mg l^-1 (two-fold) and 412 mg l^-1 (four-fold) every other day. Frequency distribution of different weight groups of fishes at the time of harvest after a 90-day growing period revealed significant differences between the normal live food system and the two-fold or four-fold treatments, but no marked differences between the latter two treatments. Mean weight of common carp was 20.76, 23.82 and 24.04 g in the normal, two-fold and four-fold treatments, respectively, whereas yield per tank ranged from 3.69 to 4.37 kg. Carp growth in these three systems was found to be strongly dependent on plankton density. The mortality of common carp did not differ from one system to another, with values ranging from 8 to 10% in the three treatments. Fish production in the four-fold treatment was not proportionate to the rise in zooplankton density and, hence, the two-fold treatment was the most appropriate for carp growth.

Chakrabarti, R. and Jana, B. B. 1992. Diversity and abundance of plankton as indices of management strategies of common carp culture. Archiev für Hydrobiologie 125: 499-509. 
 

Management induced changes of plankton community structure has been inves- tigated in the common carp (Cyprinus carpio L.) culture under five treatments in triplicate: (a) introduction of live-plankton (LFS), (b) direct tank fertilization (MS), (c) direct tank fertilization and exchange of water (EMS), (d) intermediate condition with 50% manure application and introduction of 50% of live-plankton (IS) and (e) introduction of boiled rice and mustard oil cake (CS). There were altogether 30 trials during the period of March 1987 to November 1988. Direct tank fertilization resulted in the dominance of copepods and favoured the exclusive selection of Pediastrum simplex and Asplanchna sp. whereas, introduction of live plankton into the culture system favoured the dominance of cladocerans especially Ceriodaphnia reticulata. The control system was conspicuous by the absence of rotifers. The Shannon index for phytoplankton and zooplankton were maximum for MS and LFS, respectively. The indices of dominance for cladocerans and zooplankton were maximum in the LFS and minimum in the CS and MS. The index value indicated maximum similarity between LFS and IS followed by MS and EMS and minimum between MS and CS.

 

Chakrabarti, R. and Sharma, J. G. 1998. Influence of management protocols on common carp growth under nursery conditions: relative importance of food and water quality. Journal of Aquaculture International 6: 293-301. 

Twenty outdoor holding tanks (10 m^-3 each), were filled with ground water and grouped into five feeding schemes: live zooplankton cultured outside the fish growing tank (LFS); direct nursery pond fertilization schedule in static (MS) as well as in exchanged water (EMS); intermediate conditions between the LFS and MS (IS); and supplementary food system using mixture (1:1) of finely ground mustard oilcake and boiled rice (SFS). Two hundred common carp (Cyprinus carpio) fry were introduced into each of the twenty outdoor tanks maintained at ambient temperature outside the laboratory. After 90 days of rearing, the fish were harvested and analysed for various growth parameters and food conversion efficiency. The average weight of carp attained in the LFS was significantly higher than that in the other four feeding schemes. The frequency distribution of final body weight of common carp showed the preponderance of large and small fish in the LFS and MS, respectively. Likewise, plankton intake by the carp fry was highest in the LFS. The rate of survival was much higher in the LFS as compared with the rest of the treatments. The water quality remained far better in the former than the latter.

Chakrabarti, R. and Jana, B. B. 1998. Effects on growth and water quality of feeding exogenous plankton compared to use of manure in the culture of mrigal, Cirrhinus mrigala, and rohu, Labeo rohita, fry in tanks. Journal of Applied Aquaculture 8: 87-95.

Advanced fry (2.0-3.5 g) of mrigal, Cirrhinus mrigala, and rohu, Labeo rohita were cultured in 9,580-L tanks for 90 days. Individual weight gain and total yield were compared among five culture regimes: (1) live zooplankton fed to fry stocked at 1,312 fry/tank (LF); (2) fry stocked at 1,642 fry/tank (HLF); (3) manure- based system (1,312 fry/tank) without water exchange (M); (4) manured-based system (1,312 fry/tank) with water exchange (EM); (5) a control (1,312 fry/tank) (C) fed with mustard oil cake and boiled rice treatment. There were three replicates for each treatment. Weight gain of both species of carp stocked at the LF rate and fed zooplankton was significantly higher (P<0.05) than that of fish in the other treatments. Survival of rohu and mrigal was significantly higher (P<0.05) in LF treatment than that in M treatment. Yields for both species in the HLF were significantly higher (P<0.05) than those in the remaining treatments. Dissolved oxygen was lower in M (P<0.05) than that in other treatments. Mean BOD, COD, phosphate, nitrate-N were markedly higher (P<0.05) in the M treatment compared to measurements in other systems. The results suggest that raising carp fry in nursery ponds using exogenous feeding of zooplankton is of considerable importance because such feeding would support high rates of survival and growth through maintenance of better water quality and greater abundance of zooplankton in culture systems.

Sharma, J. G. and Chakrabarti, R. 1999. Larval rearing of common carp Cyprinus carpio: A comparison between natural and artificial diets under three stocking densities. Journal of World Aquaculture Society 30: 490-495.

Common carp Cyprinus carpio larvae were cultured under two feeding conditions: live food or an artificial diet for 40 d in recirculating systems. Three stocking densities of 25 (low). 50 (medium) and 100 (high) larvae/15-L aquarium were maintained for each feeding treatment. Significantly higher survival (91%) and growth (401.08±2.61 mg) were observed in the low density live food system. Average weight of larvae in the live food system was 3 to 5-fold higher than larvae at the same stocking density for the artificial diet. Proteolytic activity showed a direct relationship with the length of the digestive tract (r=0.95). The highest enzyme activity was observed in the low density live food system. Survival and growth of common carp larvae are influenced by both the stocking density and the type of food.

Sharma, J. G. and Chakrabarti, R. 2000. Replacement of live-food with refrigerated-plankton food for Cyprinus carpio (L) larvae cultured with three different types of biological filters. Current Science 79: 214-219. 

Common carp, Cyprinus carpio (L.) larvae were cultured with either live-food or refrigerated-plankton food in the recirculating system. Three types of biological filters: (i) pebbles, foam and weed (Lemna major) filter system (PFWS), (ii) pebbles and foam filter system (PFS), and (iii) only weed (Lemna major) filter system (WS) were used for each feeding scheme. After 40 days of culture, a significantly higher (P<0.01) rate of survival was obtained with the live-food system (LFS) than the refrigerated-plankton food system (RPFS) regardless of filtration type. The final average weight was influenced by both filtration unit and food. Significantly higher (P<0.05) values for average weight (130±1.5 mg), specific growth rate (4.69±0.01), and RNA/DNA ratio (5.60±0.13) were obtained in the PFWS of live-food treatment. Food was more efficiently utilized in the LFS as indicated by the significantly lower (P<0.05) values of food conversion ratio (0.93 to 1.60) compared to the RPFS (3.87 to 4.91). Amylase (0.09-0.162 mg maltose/mg protein/h) and proteolytic enzyme (2.52-4.70 mg tyrosine/mg protein/h) activities were significantly higher in the LFS than the RPFS. Significantly higher values for ammonia (0.014±0.031 mg/l), phosphate (0.150-0.157 mg/l) and COD (197-207 mg/l) were observed in the PFS than for the other two filter systems. Results indicate that use of Lemna major alone or in conjugation with pebbles and foam helped in the maintenance of improved water quality in the culture system, which resulted in the better performance of carp larvae.

Chakrabarti, R. and Kumar, S. 2001. Effect of feed protein manipulation on the survival, growth and enzyme activities of Cirrhinus mrigala larvae. In: larvi 2001, Fish and Shellfish Symposium (Eds. C.I. Hendry, G. V. Stappen, M. Wille M. and P. Sorgeloos). European Aquaculture Society, Special Publication No.30. Belgium, pp. 129 -132.

Growth performance of Cirrhinus mrigala larvae fed with artificial diet containing three different levels of (30, 40 and 50%) protein and the effects of food protein concentration on enzyme activities were studied. Survival rate was 100% in all the three feeding regimes. Average weight of mrigal was significantly higher in the group (510.07±7.57 mg) fed with diet containing 40% protein, followed by 30% protein (364±18.8 mg) and 50% protein rich diet (338.4±7.21 mg) fed fish. Food conversion ratio was significantly lower in 40% protein rich diet (2.65±0.07)  fed group than other two treatments. Proteolytic enzyme activity was significantly higher in 40% protein fed group (107±14.7 µg tyrosine mg^-1 protein h^-1) followed by 50 (81.6±12.78 µg tyrosine mg^-1 protein h^-1) and 30% (76.09±13.87 µg tyrosine mg^-1 protein h^-1) protein fed groups. Whereas, amylase activity was significantly higher in 50% protein containing diet fed larvae than other two treatments. The increasing percentage of protein in diets also affected the water quality parameters especially, dissolved oxygen, ammonia and nitrite levels.

 Sharma, J. G., Gwak, W-S, Masuda, R., Tanaka, M. and Chakrabarti, R. 2006. Survival, growth and RNA/DNA ratio of Pagrus major cultured under three different feeding regimes during early development. Asian Fisheries Science (Asian Fisheries Society) 19: 389-400.

The nutritional status of red sea bream Pagrus major (30-day-old) cultured under three different feeding regimes: 1) rotifer, Artemia and artificial diet (RAA), 2) rotifer and artificial diet (RA) and 3) artificial diet (A) only were evaluated depending on RNA/DNA ratios. The duration of the experiment was four weeks. The final average weight of fish was significantly (P< 0.05) higher in RAA (1555 ± 119 mg) than RA (1010 ± 145 mg) and A (927 ± 170 mg). Specific growth rate was significantly (P< 0.05) higher in RAA (7.376) and RA (5.617) at the end of the first week of culture compared to the other weeks. In artificial diet fed fish, SGR was significantly (P< 0.05) higher at the end of the second week (4.542) compared to the other weeks. The DNA concentration was significantly (P< 0.05) higher at the end of the second week of feeding than in the remaining culture period regardless of feeding conditions. The RNA concentration increased from the first to the second week of culture, followed by a decrease in RNA concentration at the end of the third week and then a re-increase at the end of the fourth week in three treatments. The amount of RNA of fish was significantly (P< 0.05) higher in RAA and RA treatments than in artificial diet fed fish at the end of the second week. The RNA/DNA ratio showed a direct relationship with growth rate in these three different treatments. The RNA/DNA ratio was significantly (P< 0.05) higher in RAA than RA and A showing the superiority of this feeding regime during early development.

 Kumar, S., Sharma, J. G. and Chakrabarti, R. 2007. Acute toxicity of ammonia to a freshwater teleost, Labeo bata larvae. Toxicology & Environmental Chemistry (Taylor & Francis) 89: 327-336.

Ammonia toxicity tests were performed with Labeo bata (bata) larvae of three different size groups. One hundred percent survival of larvae (500.0±4.0 mg) was recorded when exposed to ammonia concentrations of 1.0–13.56 mgL^-1 at 96 h of exposure. Bata larvae exposed to ammonia concentrations of 15.8–25mg L^-1 showed 10–74% mortalities. The 96 h LC50 value for 200 (±5), 250 (±2) and 500 (±4) mg bata larvae were 11.5, 16.8 and 22.5 mgL^-1 un-ionised ammonia concentrations, respectively. When fish were exposed to different doses of ammonia, behavioural changes immediately occurred even at the lowest dose. At first, the fish became hyperexcitable, the skin darkened and they showed an increased ventilation frequency, fish behaviour became normal, 24 h after exposure. A 96 h LC₅₀ value of un-onised ammonia showed direct relationship with the increasing size of bata larvae.