Salinity During Early Development Influences Growth and Survival of Florida Red Tilapia in Brackish and Seawater

Abstract

Abstract Growth of juvenile Florida red tilapin (1.57 g average weight) spawned and sex‐reversed (monosex male) at salinities of 4 ppt and 18 ppt was compared at rearing salinities of 18 ppt and 36 ppt in 200 L aquaria under controlled photoperiod (12 L:12 D) and temperature (28 C). Growth was significantly higher for progeny spawned at 18 ppt than those spawned at 4 ppt under both rearing salinities with no difference observed between 18 ppt and 36 ppt. In another experiment, growth of juvenile progeny (0.98 g average weight) spawned and sex‐reversed at salinities of 2 ppt and 18 ppt was compared in 24 m 3 outdoor pools at 36 ppt. When water temperatures exceeded 27 C, growth and survival were not significantly different between these groups. However, when temperatures fell below 25 C, growth and survival were significantly higher among progeny spawned at 18 ppt. The results showed that progeny spawned and reared through early ontqenetic development in brackishwater are better adapted for growth in brackish and seawater and suggested that these fish may have higher resistance to cold‐stress in seawater than progeny spawned in freshwater.