Feeding habits of Mormyrops anguilloides (Mormyridae) in lacustrine and riverine habitats of a West African basin.

Based on 195 samples from the Bia River (Ivory Coast-Ghana) on which a hydr o-electric dam was built in 1959, the diet of Mormyrops anguilloides was st udied in relation to fish size, locality and season. A feeding index was co mputed by combining the occurrence and weight percentages of the items iden tified in the stomach contents. In the lacustrine environment, M. anguilloi des mainly fed on fish, especially on tilapias (Cichlidae) Sarotherodon mel anotheron and Tilapia spp., whereas in riverine localities two groups of pr eys (Crustacea and fish) were mainly eaten. This dietary shift is statistic ally significant. In the lake, the dirt varied significantly with size; you ng fishes preyed on benthic invertebrates, mostly aquatic insects whereas l arger fishes were exclusively piscivorous. Significant variation in the die t was observed between seasonal samples examined from the lacustrine enviro nment.