Effect of stocking density on the growth of estuary grouper, Epinephelus salmoides Maxwell, cultured in floating net-cages

Abstract

Studies on the effect of stocking density on the growth of estuary grouper ( Epinephelus salmoides) were conducted in floating net-cages. Four stocking densities (15, 30, 60 and 120 fish/m 3) and two sizes of fish (26 ± 0.2 gm and 15.2 ± 0.1 gm) were studied. Results of the present study indicate that fish at the stocking density of 60 fish/m 3 grew equally fast and showed comparable food conversion ratio and survival rate as those at lower stocking densities of 15 and 30 fish/m 3. The net-yield of fish at a stocking density of 60 fish/m 3 was 1.9 and 3.5 times that of fish at densities of 30 and 15 fish/m 3, respectively. However, at 120 fish/m 3, a remarkable decrease in the weight-gain per fish, mean fish weight, efficiency of food conversion as well as survival rate was recorded. The possible effects of stocking density on the growth of estuary grouper under cage-culture conditions were discussed.