Diversity and Distribution of Freshwater Fishes in Oguta Lake, Southeast Nigeria

Abstract

The ichthyofaunal composition of the largest natural lake in Nigeria - the Oguta Lake, was investigated from January, 2012 to December, 2013. Bi-monthly random samples of fish catches of artisanal fishers employing hook and line, gill net, cast net, bagnet and local traps were analysed. A total of 1,989 fishes were sampled comprising 6 orders, 22 genera, and 32 species spread into 18 families. The Perciformes, Cichlidae and Tilapia zill were the most abundant fish order, family and species, respectively. The study reveals that species diversity was highest at station 4 (Osemotor) though no significant spatial differences were detected. The lake is of ecological significance in accommodating some threatened species like Erpetoichthys calabaricus and serving as a source of broodstock of Clarias gariepinus for aquaculture.  A seriation analysis of species presence/absence matrix in the lake reveals Tilapia mariae, Synodotis schall, Mormyrus rume, Synodontis nigrita and Petrocephalus banebane are important fish species to ecosystem health of the lake. The fish abundance and diversity values in present study are lower than the findings of previous studies in the same water body, suggesting need for proper and articulated management.

Keywords: Biodiversity, blue Lake, conservation, food security, sustainable management