Description

Abstract: An experiment was conducted in outdoor concrete tanks (4.9 m x 4.8 m x 1.75 m) at the Institute of Agriculture and Animal Science (IAAS) of Nepal to evaluate the growth of grass carp and Nile tilapia fed with napier grass in polyculture, to evaluate water quality regimes of pond water, to determine the compositions of foods consumed by Nile tilapia, and to determine the optimal ratio of grass carp to Nile tilapia in polyculture. The experiment was laid out in a completely randomized design with five treatments replicated thrice. Five stocking ratios of grass carp to Nile tilapia were tested: (1) grass carp only at 0.5 fish/m2(control); (2) grass carp at 0.5 fish/m2plus tilapia at 0.25 fish/m2;(3) grass carp at 0.5 fish/m2 plus tilapia at 0.5 fish/m2; (4) grass carp at 0.5 fish/m2 plus tilapia at 1 fish/m2; and (5) grass carp at 0.5 fish/m2 plus tilapia at 2 fish/m2. Grass carp fingerlings (39.3