Effects of High Salinity on the Larviculture of Asian Seabass Lates calcarifer in Outdoor Systems

This study estimated the survival rate and growth performance in the larviculture of Asian Seabass Lates calcarifer in extensive outdoor conditions at different levels of salinity (33, 36, 39, and 42 parts per thousand) at 33.3-38.0 degrees C. The experiments were conducted in triplicate with 1,000 larvae per outdoor 500-L fiber-reinforced plastic tank. The control group was maintained at a salinity level of 42 parts per thousand indoors. The larvae were manually counted 18 h after hatching, and larvae that were 1.26 mm in length were transferred to indoor and outdoor tanks with salinities of 33, 36, 39, and 42 parts per thousand, where they were continuously monitored. To minimize cannibalism, the larvae were manually graded and monitored for survival after 14 d. The survival rate and growth performance of the developing larvae were monitored from day 21 to day 45. The best salinity level for larval survival outdoors was 33-39 parts per thousand. There were significant differences between the indoor and outdoor systems in terms of survival rate (29-44%) and specific growth rate (7.5-10.5%). Overall, outdoor larviculture of Asian Seabass is feasible at 33-42 parts per thousand salinity levels.