Effects of stocking densities of tilapia Oreochromis niloticus (Linnaeus, 1758) with the inclusion of silver carp Hypophthalmichthys molitrix (Valenciennes, 1844) in C/N-CP prawn Macrobrachium rosenbergii (De Man, 1879) culture pond

Abstract

Listen

Translate article

The effects of stocking density of tilapia Oreochromis niloticus with the inclusion of silver carp Hypophthalmichthys molitrix were evaluated in the C/N-CP prawn Macrobrachium rosenbergii farming system in triplicate. Management practices were same for all treatments. Bamboo side shoots were posted vertically into the pond bottoms as a periphyton substrate. A locally formulated and prepared feed containing 15.44% crude protein with a C/N ratio 15 were applied twice daily in all ponds. Maize flour was supplied in water for raising the C/N ratio 20 in all treatments. Water quality parameters, except transparency and chlorophyll a, did not differ significantly (P > 0.05) among the treatments. The periphytic abundance and biomass differed significantly (P < 0.05) among the treatments and even among different months. Although the individual harvesting weight, individual weight gain, and SGR were significantly higher (P < 0.05) in the T10000 treatment compared to T15000 and T20000 treatments, respectively, the gross and net yields of tilapia were significantly higher (P < 0.05) in the treatment T20000 followed by T15000 and T10000 treatments resulting in higher combined gross and net yield of both prawn and tilapia (16.05 and 16.92%, 32 and 33.59% from the later two treatments, respectively) with a higher economic return (BCR 0.53) during a 122-day culture period. As a whole, the study revealed that prawn, tilapia, and silver carp with a stocking density at 30,000, 20,000, and 1250 ha−1, respectively, was found to provide an optimum and sustainable production as well as economic benefit in the C/N-CP-based culture system.