Effect of Stocking Density on Growth, Survival and Economic Return during the Nursery Rearing of Rohu, Labeo rohita (Hamilton) Larvae in Hapa Production Systems Installed in Community Village Ponds

Abstract

A detailed study on nursery raising of rohu, Labeo rohita larvae in community village ponds in hapa production system was attempted at six different sites of Gujarat, India. Rohu larvae were stocked at six densities; 100, 250, 500, 750, 1000, and 1500 larvae/m³ in hapas (3 x 2 x 1 m) installed in the village ponds. Growth performance and survival were evaluated over a rearing period of four weeks. The growth performance and survival were significantly highest in stocking density of 100 larvae/m³, while the lowest survival was recorded in stocking density of 1500 larvae/m³. The rohu larvae stocked in hapa with density of 750 larvae/m³ reported the highest yield, followed by 500 larvae/m³. Evaluation of economic returns indicated that the rohu stocked in hapa with 750 larvae/m³ obtained better benefit cost ratio (1.4) and thus stocking density of 750 larvae/m³ can be considered as optimal for rearing of rohu larvae under hapa production systems in village ponds. This study will benefit the aquaculture farmers for cost-effective raising of fish seed in village ponds.