Growth and survival of Oreochromis niloticus, O. mossambicus and their F1 hybrids at various salinities

Abstract

Growth and survival of Oreochromis niloticus, O. mossambicus, and their F₁ hybrids were studied at various salinities (0-32 ppt) in net cages inside 12-tonne concrete tanks after acclimation. Growth, measured as weight gain, and survival were assessed after three months of culture. Results showed that although O. niloticus, O. mossambicus, and their F₁ hybrids can be acclimated and grown at varying salinities, optimum salinity ranges for good growth varied greatly. The salinity ranges for good growth of O. mossambicus and F₁ hybrids were wider than O. niloticus. O. mossambicus had the highest growth rates at 15 and 32 ppt. The optimum salinity range for growth of F₁ hybrids was 15-32 ppt, while for O. niloticus it was 0-10 ppt. Salinity up to 20 ppt had no significant effect (P>0.05) on survival of all test strains. However, at 25-32 ppt survival of O. niloticus was significantly lower (P<0.05) than that of O. mossambicus and the F₁ hybrids.