Nursery rearing of Asian seabass (Lates calcarifer Bloch, 1790) fry in indoor recirculatory aquaculture system

The present study evaluated the effect of different stocking densities on the growth performance, cannibalism and survival of Asian seabass (Lates calcarifer) fry reared in an indoor recirculating aquaculture system (RAS). Fry (25 days post-hatch) were stocked at three densities: 100T1, 200T2, and 300(T3) individuals per m3 and reared for 50 days under controlled conditions. Growth parameters, water quality, cannibalism rate and survival were monitored throughout the study. Water quality parameters remained within acceptable limits across treatments, although slight variations were observed with increasing density. Fish reared at the lowest density (T1) exhibited significantly higher growth performance, with maximum length gain (8.40±0.95cm), weight gain (10.2 ± 0.16g) and better feed conversion efficiency. In contrast, higher stocking densities (T2 and T3) resulted in reduced growth and feed efficiency. Cannibalism rate increased significantly with density, reaching the highest value in T3(13.55 ± 2.84%), while survival rate decreased from 96.54 per cent in T1 to 86.45 per cent in T3. The results indicated that lower stocking density improves growth performance, reduces cannibalism and enhances survival in Asian seabass fry under RAS conditions. Optimizing stocking density is therefore critical for sustainable and efficient nursery rearing of seabass.