Evaluation of Oreochromis niloticus× O. aureus hybrid progeny of different geographical isolates, reared under varying management regimes

Ten Oreochromis niloticus× O. aureus hybrids, progeny of different geographic isolates, were evaluated in polyculture with common carp, silver carp and grass carp. Traits tested included growth rate, survival, yield and proportion of males. The hybrid combinations O. niloticus ‘Nile’ (Egypt)× O. aureus ‘Mehadrin’ (Israel), and O. niloticus ‘Ghana-74’× O. aureus ‘Nile’ showed similar or better performance compared to the ‘Ghana-74’בMehadrin’ hybrid developed earlier at Dor. This suggests that the ‘Nile’ strains of both O. niloticus and O. aureus are potential candidates for commercial hybridization. The low proportion of males (30%) obtained with O. niloticus ‘Ghana-88’× O. aureus ‘Mehadrin’ crosses suggests that the later introduction from the Volta River differs from the 1974 introduction.