Harrison Charo-Karisa: Selection for growth of Nile tilapia (Oreochromis niloticus L.) in low-input environments

Nile tilapia is cultured in low-input semi-intensive environments by many poor fish farmers. Selection for improved growth typically carried out under better conditions often produces breeds which demand more resource than can be provided on traditional fish farms. In this thesis, the author presents results of selecting for growth directly in low-input environments. Studies on early growth, cold tolerance, and effect of selection on correlated traits were carried out. This thesis shows that growth of Nile tilapia can be improved without requiring expensive supplementary feeds. The high response achieved in this study, and the short generation times of Nile tilapia indicate that farmers can benefit from genetic improvement within a few generations of selection. Because poverty alleviation and food security are primary goals in the developing world, the initiation and implementation of cheaper breeding programs will ensure that the genetically improved materials are accessible to the rural fish farmer.