Abstract

The abundant and diversity of freshwater fishes of Lake Geriyo, was studied from June to November 2015. A total of eighteen freshwater fish species belonging to fourteen families were recorded. The fish abundance increases along the months with the highest abundant and lowest recorded in November and June, respectively while the diversity remains the same throughout the sampling period. Oreochromis niloticus was the most abundant species with 25.61% of the total fish sampled while Gymnarchus niloticus was the least abundant with 1.22%. The family Cichlidae was the most abundant (45.33%) which comprises of Oreochromis niloticus, Coptodon zilli and Sarotherodon galilaeus; and Gymnarchida (1.22%) been the least abundant family. The family Cichlidae is the most diversed group with three species followed by the family Mochokidae and Mormyridae with two species each. Fish diversity was assessed by calculating some biodiversity index such as Shannon-weiner index (H), Simpson’s Dominance Index (D) and Simpson’s index of diversity (1-D).

Keywords: Diversity; Lake geriyo; Biodiversity index; Freshwater fishes; Ichthyodiversity