Species diversity, abundance and distribution of fish community of Peretorugbene River, Ekeremor L.G.A, Bayelsa state, Nigeria

Abstract

A study on diversity and distribution of fish communities were carried out in Peretorugbene river, Ekeremor Local Government Area, Bayelsa State, Nigeria for a period of eight (8) months. Fish samples were obtained at three stations once in a month from November 2017 to June 2018 with the aid of local fishers using gill nets, cast nets, hook and line and local traps for ecological studies of important fish species of Peretorugbene river. The sampling results showed a total composition of 16,575 individuals belonging to 14 orders, 22 families, 29 genera and 32 species. Cichlidae showed the highest diversity with four (4) species, second to the Mormyridae which had three species. The remaining 20 families contained a species or two. Fish diversity was observed to be higher in the month of November 2017 with 29 fish species and lowest in June 2018 with only 12 fish species. Ecological indices indicated a polydiverse community because no single species exhibited true dominance (≥ 50%). The Berger – Parker’s dominance (d) ranged from 0.00012 to 0.211 depicting dominance of a few species. Simpson’s diversity index ranged from 0.95 to 0.99. The study highlighted seven (7) rare fish species of conservation significance. In terms of Families, Clupeidae, (21.1%) was the most abundant in the river followed by Palaemonidae (16.83%), Physalidae (10.9%), Cichlidae (9.39%), Ampullariidae (7.8%), Mormyridae (6.58%), Mochokidae (5.16%), Schilbeidae (5.2%), Claroteidae (4.91%), Alestidae (4.61%). The least abundant families were the Chanidae (0.01%) and Tetraodontidae (0.01%). It is recommended that Peretorugbene river should be properly managed and protected via fisheries and policies to enhance sustainability of the natural fishery.