Commercial Aquaculture Trial of Asian Seabass, Lates calcarifer (Bloch, 1790), Across Different Salinity Levels in Coastal Areas of Bangladesh: Assessment of Growth Performance and Feed Utilisation Efficiency

ABSTRACT This study assessed the growth performance and feed utilisation of Asian seabass ( Lates calcarifer ) cultured under three salinity regimes (5–6, 8–10 and 2–4 ppt) in pilot‐scale earthen ponds in coastal Bangladesh. Fish were stocked at 60 per decimal and fed commercial pellets throughout the trial over 254 days, with water quality consistently monitored. Data were analysed using one‐way analysis of variance (ANOVA) with post hoc Games–Howell test. Significant differences ( p < 0.05) were observed among salinity treatments in final body weight (BW), weight gain (WG), length gain, specific growth rate (SGR) and daily WG. Fish at moderate salinity (5–6 ppt) showed the highest growth (final BW: 840.02 ± 1.30 g; SGR: 2.16% ± 0.01% per day). Feed utilisation metrics were also superior at 5–6 ppt, including the lowest feed conversion ratio (1.27 ± 0.002), highest feed efficiency ratio (0.79 ± 0.001) and protein efficiency ratio (1.96 ± 0.003). Survival was greatest at 5–6 ppt (85.11% ± 0.15%) than in lower and higher salinity regimes. These findings indicate that maintaining moderate salinity (≈5–6 ppt) optimises growth, feed utilisation and survival in L. calcarifer , providing practical guidance for Asian seabass aquaculture in Bangladesh.