Zootechnical performances of males of Oreochromis niloticus (Linné, 1758), Sarotherodon melanotheron (Rüppell, 1853) and their hybrids in growth phase in cages installed in pond

Abstract

In Ivory Coast, the breeding in lagoon environment has difficulty to take off because of the lack of interesting fish at the zootechnical level. In order to identify a potential candidate species for fish farming in brackish water, two pure strains of tilapia (Oreochromis niloticus and Sarotherodon melanotheron) and their hybrids (♀ S. melanotheron x ♂ O. niloticus and ♀ O. niloticus x ♂ S. melanotheron) were studied in the growth phase in cages. Thus, two hundred and forty (240) fish from a pregrowth in concrete tanks with initial average weights between 33.60 ± 2.11g and 70.25 ± 2.20g were divided into 8 lots at the rate of two lots by type of crossing. These fish were followed for six (6) months during which they received daily food containing 30% protein. The results relating to the growth performances revealed that the hybrids resulting from the crossing ♀ O. niloticus x ♂ S. melanotheron have a growth (0.70 ± 0.02 g/d) higher than those of the hybrids of ♀ S. melanotheron x ♂ O. niloticus (0.45 ± 0.01 g/d) and S. melanotheron (0.37 ± 0.03 g/d). The growth of O. niloticus was the best (1.22 ± 0.01 g/d). As for survival, the hybrids and their parents S. melanotheron recorded a higher rate than that of O. niloticus (100% against 83.33%). These results suggest that the hybrids have good adaptability to the lagoon environment like S. melanotheron. The hybrid from the cross ♀ O. niloticus x ♂ S. melanotheron, which has better inherited the resistance to the lagoon environment of S. melanotheron as well as the good growth of O. niloticus, is the best choice for lagoon fish farming. in large scale.