To evaluate the production performance of carps stocked at various stocking densities

Abstract

Four different rearing densities T1 (800), T2 (1200), T3 (1600) and T4 (2000) were stocked with ratio of 80% labeo rohita, 10% Catla catla and 10% Cirrhinus mrigala in 12 earthen ponds (in triplicate) of same size in polyculture system to study their effect on growth, survival, condition factor, feed conversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER) and net production. Each group was fed with same diet; 30% protein @ 3% of entire wet body weight for six months. The growth parameters were inversely affected by stocking density; in T1, maximum weight, length, SGR and PER were observed in all three fish species and gradually decreased in T2, T3 and T4. Condition factor and survival rate showed variation in different groups indicating no effect of their interaction. The best feed conversion ratio was observed in T1 at lower density with insignificant difference. Labeo rohita showed maximum weight and length gain (904.25% and 195.4%) followed by Cirrhinus mrigala (884.11% and 187.08%) and Catla catla (521.84% and 163.87%). Maximum production was observed in T4 in all fish species with maximum number of fish. The overall results presented here indicate that the best growth performance of all fish species was obtained at T1 with maximum production at T4 stocking density.