Keywords: sea bass, Lates calcarifer, aquatic environment, yield, forage fish, stocking densities, fish size, ponds, nitrate nitrogen, phosphate, nitrite nitrogen, salinity, dissolved oxygen
Aquatic environment and yield of sea bass (Lates calcarifer, Bloch) in ponds
This study was conducted for three years to investigate the aquatic parameters and growth of sea bass at varying stocking densities and sizes and requirement of quantity of forage fish for its culture in ponds. Two separate experiments were conducted: one for determining growth and seed stocking density and the other for ascertaining of quantity of forage fish. Under experiment 1, two trials namely, A and B were conducted with three stocking densities viz. 1000, 1500 and 2000 nos./ha of sea bass in each trial. In trial A, the specific growth rate (3.68% /day) was significantly better (P < 0.05) in T2 (1500 nos./ha stocking density), while in trial B, it was higher (2.06 and 2.00% /day) in T1 (1000 nos./ha) and T2 (1500 nos./ha), respectively, and significantly superior from T3. The survival was 100% in trial B, where advance fingerlings were used, as compared with 34.32% in trial A with fry size. The water parameters like temperature pH, salinity, dissolved oxygen, alkalinity nitrate–N
2and phosphate were recorded in all the experiments.