Saline water for juvenile giant trahira during feed training

The objective of this study was to investigate the effect of different water salinities on juvenile Hoplias lacerdae during feed training. Salinity levels of 0, 3, 6 and 9 g salt L-1 were used. Juveniles (3.33±0.1 cm and 0.6±0.09 g) were stocked at a density of six fish L-1 in aquaria (10 L volume) with supplementary aeration. Weight gain, length gain, and rates of survival, mortality, and cannibalism were evaluated after 20 days. Total mortality was observed in 0 g of salt L-1. The best survival rates of 98.7 and 97.5% were recorded in 3 and 6 g of salt L-1, respectively. The greatest weight gain was recorded in fish grown in 3 g of salt L-1 followed by fish grown in 6 g of salt L-1. Length gain was similar in the 3 and 6 g salt L-1 groups. No weight or length gain was recorded in 9 g of salt L-1. According to regression equations, the optimum water salinity was 5.15, 4.03 and 4.55 g of salt L-1 for survival rate, weight, and length gain, respectively. Salinity between 4.03 and 5.15 g of salt L-1 during feed training of juvenile giant trahira improves productive performance.