Sharma, J. G. and Chakrabarti, R. 1997.
Effects of filtration and aeration on survival and growth of Ctenopharyngodon
idella fry in recirculation system. Indian Journal of Experimental Biology
35: 56-58.
Ctenopharyngodon
idella fry (15 ± 0.02 mg) were stocked in 15 l glass aquaria at
four stocking densities (200, 400, 800 and 1600/m3) of two
recirculating systems: one with filtration and aeration (RSFA) and other
without filtration and aeration (RS) and reared for 35 days to evaluate the
effects of water filtration and aeration on growth, survival and production of
fish and water quality. Highest average weight was obtained in normal
density-RSFA. Growth differences were not significant between two-fold and
four-fold RSFA. Better survival, growth and production of fish in RSFA than RS
were due to prevalence of better water quality in terms of higher values of pH and dissolved oxygen and lower
values of free CO2 and ammonia prevailed in RSFA than RS. Water
requirement for per unit fish production in RS was 1.5 to 2.5-fold more than
that of RSFA. There was no mortality of fish in normal stocking density of both
RSFA and RS. Among the four stocking densities of RSFA, minimum survival were
observed in eight-fold stocking density, whereas, it was 47 and 54% in
four-fold and eight-fold RS, respectively.
Sharma, J. G. and
Chakrabarti, R. 1998. Effects of different stocking densities on survival and
growth of grass carp, Ctenopharyngodon idella larvae using recirculating
system. Journal of Applied Aquaculture 8: 79-83.
Grass carp,
Ctenopharyngodon idella, larvae (15 mg) were cultured for 35 days in
glass aquaria in a recirculating water system at four stocking densities: 200,
400, 800, and 1,600/m3. Initially, fish were supplied with live
zooplankton at 4, 8, 16, and 32 mg (dry weight) per aquarium for stocking
densities of 200, 400, 800, and 1,600/m3, respectively. After 20
days, feeding rates were doubled. Percent survival was maximum (100%) and
minimum (81%) at stocking densities of 200 and 1,600 larvae/m3,
respectively. Average weight (66 mg) was significantly (P<0.05) higher in aquaria containing 200 larvae/m3
than for the other stocking densities (44-60 mg). Specific growth rate
decreased with increasing stocking density (r= -0.95). FCR's showed the
opposite trend (r=0.94). The ammonia level was significantly (P<0.05) higher in 1,600
larvae/m3 treatment (0.027±0.002 mg/L) followed by 800/m3,
400/m3, and lowest (0.021±0.001 mg/L) in 200/m3 stocking
density. Survival and growth of grass carp larvae were influenced by water
quality, which is regulated by the stocking density of fish.
Sharma, J. G. and Chakrabarti, R. 2003.
Role of stocking density on growth and survival of catla, Catla catla and
rohu, Labeo rohita, larvae and water quality in a recirculating
system. Journal of Applied Aquaculture14: 171-178.
Catla, Catla
catla, and rohu, Labeo rohita, fry were cultured at 6,667, 8,333,
and 10,000/m3 in 15-L aquaria in recirculating systems for 30 days.
Larvae were fed with exogenous live plankton. Cultures at 6,667 and 8,333
larvae/m3 showed significantly (P<0.05) higher survival and growth than larvae
stocked at 10,000 larvae/m3 for both species. Food was more
efficiently used in low stocking density, as evident from the significantly (P<0.05) lower values of
teed conversion ratio in lower density compared to those for high stocking
density. Specific growth rate of both species was high in the early stage and
gradually declined along with the ontogenic development. Dissolved oxygen level
was higher in the low density system than in the high density one. Values of
phosphate and COD increased during the experiment. Ammonia, nitrite, phosphate,
and COD levels were significantly (P<0.05)
higher in the 10,000 lar- vae/m3 density system than in the other
two systems for both species. Considering the survival and growth of fish and
values of water quality parameters, it appears that stocking density can be
raised up to 8,333 larvae/m3 with a recirculating system for both
catla and rohu.
