Fish Diversity in Relation to Aquatic Macrophytes and Physicochemical Parameters of on a Lake in Asaba, Southern Nigeria

Abstract

An investigation of fish diversity in relation to aquatic macrophytes and physicochemical parameters of Ona Lake in Asaba was carried out within a period of eighteen months. Fish samples were collected fortnightly from three sampling sites using cast, gill and trigger nets. Aquatic macrophytes found in close association with the fishes were hand picked from a planked canoe. Results obtained showed the presence of the following fish species: Heterotis niloticus Citharinus citharus, Labeo senegalensis, Distichodus rostratus, Malapterurus electricus, Protopterus annectenes, Hyperopisus bebes, Synodontis clarias, Synodontis oceilflfer. Xenomysirus nigri, Oreochromis niloticus, Ctenopoma kinsgsleyae, Channa obscura, Clarias gariepinus, Tilapia melanotheron and Oreochromis aureus. Out of 603 fish sampled, 60 (9.95%) were obtained from site A, 360 (59.70%) from site B and 183 (30.35%) from site C. Aquatic macrophytes found in the lake were: Ipomoea aquatica, Pistia stratiots, Azolla africana, Salvinia numphellula, Utricularia foliosa, Ceratophyllum demersum, Nymphaea lotus, Nymphaea maculate, Leersia hexandra Paspahum polystachyum, Diplazium sammatii and Hydrolea glabra. The diversity of fish species and aquatic macrophytes sampled were significantly (P>0.05) different in the three sampling sites.