Studies on the relative growth and production of the estuary grouper Epinephelus salmoides Maxwell were conducted in floating net-cages at 5 different stocking densities to determine the optimal level for stocking for commercial culture. The fish were stocked at densities of 15, 30, 60, 90 and 120 fish per m3, and reared for a period of 8 months. Results of the present study indicated that fish stocked at a density of 60 fish m-3 grew equally fast and showed a food conversion ratio, mortality rate, and condition factor comparable to those at the lower stocking densities of 15 and 30 fish m-3. At the end of the experiments, net-yield and production at this level of stocking density (60 fish m-3) were not significantly different from those at the higher stocking densities of 90 and 120 fish m-3, but showed increases of 86.7% over those at a stocking density of 30 fish m-3 and 294.2% over those at a stocking density of 15 fish m-3. The stocking density of 60 fish m-3 is therefore taken as the optimal stocking rate for economical production of estuary groupers in floating net-cages. The estuary groupers take 7 to 8 months to grow from 15-16 g to marketable size (>500 g) at a stocking density of 15 fish m-3, 8 to 9 months at a stocking density of 30 to 60 fish m-3 and 11 to 12 months at 90 to 120 fish m-3. © 1979 Springer-Verlag.
