Studies on fish species diversity, abundance and Distributon along Onitsha axis of River Niger, Anambra State of Nigeria

Abstract

A study on biodiversity, abundance and distribution was carried out in Onitsha Axis of River Niger in Onitsha North and South Local Government Area, Anambra State, Nigeria for a period of three months. The area was partitioned into Station I (Emejuru), Station II (Bridge Head) and Station III (Akpaka). Fish samples were collected weekly from July to September, 2019 with the aid of fisher folks using gill nets, cast nets, hook and lines and local traps. The results showed a total composition of 4,645 individuals belonging to 15 families and 31 species. Momyridae showed significance (p<0.05) species diversity with seven (7), followed by Bagridae (5) spp. with the remaining 13 families having one and two spp. Station III Akpaka recorded the highest fish diversity of 37%, followed by Station I Emejuru 34% and Station II Bridge head 29%. In terms of species abundance, Bagrus bayad 13.9% >bagrus docmak 8.8% >Chryschythys Nigrodigitatus7.2% >Bargus filamentous 4.5% >Malapters electricus 4.4% >Heterotis niloticus 4.0% >Orochromis niloticus 3.8% >Mormyrus macrophatalmus 3.3%) recorded the highest, followed by Heterobranchus bidorsalis, Mormyrus rume, Mormyrus tarpirus, Mormyrus senegalensis, Schibe mystus Synodontis clarias and Cithrinus citharus had 2.2%, 2.3%, 3.0%, 1.7%, 2.9%, 1.6% and 3.2% respectively, and Hypothermirus pissitacus the least with 0.4%. This research shows that the Onitsha axis of the River Niger is still rich in fish species diversity and abundance; hence concerted efforts should be made by the various government agencies to see that laws guiding the proper use of water bodies are enforced in the Onitsha axis of the River Niger, to enhance economics, conservation and sustainability.