Feeding relationships among Tilapia zillii (Gervais,1848),Tilapia guineensis (Bleeker,1862) and their hybrid in Ayamé Man-Made Lake,Côte d'Ivoire

The stomach contents of 122 specimens of tilapia zillii,121 of tilapia guineensis and 227 of their hybrid were studied in ayamé man-made lake during two years between august 1995 and september 1997 in order to analyze their diet composition and interspecific diet overlap. the samples were taken using two gill-nets batteries with mesh size 10,12,15,20,25,30,35,40 and 50 mm. food items identified from stomach contents were analysed using the index of food preponderance (ifp). the two parental species and their hybrids consumed a great variety of items preys from animal and plant origin. the insect diptera and the macrophytes were the most important item in the diet of these species. in the food of parental species,molluscs,coleoptera and zooplankton also consisted some important items. the food overlap analysis showed that t. zillii,t. guineensis and their hybrids share a wide range of prey types. the three species had a generalized feeding behaviour and the feeding strategy of the hybrid individuals is closer to this of tilapia zillii. competition for food is probably minimal,since the three fish species eat a wide range of foods and the abundance of main preys. copyright 2013 zoological society of pakistan.