Effect of salinity on the rearing performance of golden trevally (Gnathanodon speciosus Forsskål, 1775) juvenile
Abstract
This study aimed to evaluate the effects of salinity on the growth, survival, feed efficiency, and shock tolerance of golden trevally juveniles. Juveniles with an initial size of 2.0 cm and 0.18 g/fish were randomly stocked in composite tanks (round cylinders) with a volume of 70 L/tank. Four salinity levels were tested: 5‰, 15‰, 25‰, and 33‰. The fish were reared at a density of 2 fish/L and fed pellet feed at a rate of 5-7% BW/day, divided into four times per day. Each treatment was replicated three times over a period of 28 days. The results indicated that salinity significantly affected the growth parameters, coefficient of variation, biomass, feed efficiency, survival, and temperature shock tolerance of fish. In general, fish reared at salinity levels of 25 - 33‰ achieved better results than those reared at salinity levels of 5 - 15‰. However, fish reared at low salinity levels (5 - 15‰) were found to tolerate freshwater shock better than those reared at high salinity levels (25 - 33‰). Notably, salinity did not affect the deformity rate of fish. The study suggests that a salinity level of 25 - 33‰ is suitable for rearing golden trevally juveniles.
