Fish species composition and distribution in an urban perturbed stream, Southern Nigeria
The abundance and distribution of fish species in River Orogodo were studied. Sampling was conducted in three stations of the river, from January 2006 to December 2007. The river was demarcated in accordance with local hydrographic conditions as well as intensity of anthropogenic activities along the stretch. Thirty seven species of fish belonging to 20 families and 28 genera were recorded. Cichlidae, clariidae and bagridae dominated the catch by the species; Chromidotilapia guentheri, Hemichromis fasciatus,, Clarias gariepinus,, Auchenoglanis biscutatus and A. occidentalis. The species richness and general diversity were slightly depleted in the mid-stream station (station II) compared to the up- and downstream stations. This probably resulted from the high anthropogenic activities and the resultant effects on key physico-chemical parameters in stations II. The ichthyofauna of River Orogodo was compared with other rivers in the Niger delta and elsewhere in the West African sub-region. The need to reduce the effects of anthropogenic pressure on aquatic resources was recommended.
Keywords: Fish, Communities, distribution, abundance, River Orogodo