The Fish Fauna of Otamiri River, Imo State, South East Nigeria: The Composition, Abundance and Distribution, and Management Issues

The composition, abundance and spatial distribution of fish in Otamiri river was investigated between April 2021 and March 2022. Fish sampling was carried out from eighteen (18) demarcated sampling zones along the river. The physiochemical parameter obtained in each of the sampling zones are similar and consistent to the data collected from rivers in South Eastern Nigeria. Twenty (20) fish families were sampled and identified into thirty-seven species. The families of Cichlidae (1919, 26.35%), Clariidae (1807, 24.82%), Bagridae (1612, 22.14%) and Mormyridae (402, 4.52%) are the dominant fisheries of the river. The family of Polypteridae (161, 3.22%), Channidae (184, 2.53%), Malapteruridae (124, 1.71%), Anabantidae (120, 1.68%), Phractolaemidae (141, 1.94%), Notopteridae (136, 1.87%), Nandidae (117, 1.61%), Pantodontidae (113, 1.55%), Cyprinidae (101, 1.30%) and Cyprinodontidae (131, 1.80%) are sub-dominating fisheries while the families Characidae (44, 0.61%), Hepsetidae (97, 1.33%), Schilbeidae (41, 0.56%), Mastacembellidae (10, 0.14%), Clupeidae (10, 0.14%), Gymnarchldae (13, 0.18%) are occasioned fisheries. The species abundance and family diversity was ascertain to be evenly spread through the length of the sampled station and compared favourasly with the species diversity in similar river in South-East Nigeria against the influence of several environmental factors observed. The river is under great influence and perturbation from indigenous inhabitants who explore the river eco-system for sand and gravel for commerce, destabilizing the eco-system, and waste discharge into the river from industrial waste. Therefore to ensure and maintain the stability of the water, Government at all levels and the leaders of the indigenous inhabitants are encouraged to check the illegal activities of commercial sand and gravel dredgers and thus ensure the stability of the aquatic system. Keywords: Otamiri-River, Fish-fauna, Biodiversity, Distribution, Abundance.