Composition, abundance and distribution of non-cichlid fish community in Ogbo stream and its floodplain, Enhwe, Delta State, Nigeria

Abstract

A preliminary survey of the composition, abundance and distribution of non-cichlid fish community was carried out at Ogbo stream and its floodplain in Enhwe, Delta State Nigeria. Water samples and fishes were sampled and analyzed using APHA methods and standard fishing gear respectively. The physicochemical parameters revealed distinct values for station 1 (Temperature: 25.63°C, Transparency: 25.09 cm, Sulphate: 7.56 mg/L) and station 2 (Temperature: 23.60 °C, Transparency: 19.90 cm, Sulphate: 6.68 mg/L). Among the parameters, only Temperature, Transparency, and Sulphate exhibited a noteworthy difference (p<0.05) between the two stations. Transparency had a negative correlation with other parameters in Station 1. A total of 725 individual fish species belonging to eight families and genera were sampled. Among the notable findings, Clariidae emerged as the most abundant family, constituting 82.90% of the total relative abundance across both stations. Clarias camerunensis exhibited the highest abundance, comprising 62.20% of the total individuals sampled. Parachanna africana and Clarias pachynema also demonstrated significant presence, contributing 15.00% and 13.20% to the total relative abundance, respectively. ANOVA indicates a significant difference in the composition and abundance of fish species between the stream and floodplain (p < 0.05), emphasizing the influence of habitat-specific factors. The Margalef’s richness (1.67), dominance (0.64), diversity (1.32) and evenness (0.34) index of fishes was higher in the stream than in the floodplains. Magnesium, sulphate, temperature, and transparency were positively correlated to the distribution patterns of Pantodon bucholzi, Clarias jaensis, Phractolaemus ansorgei, and Heterotis niloticus in station 1, with the exception of P. africana and Polypterus senegalus. There was a negative association between dissolved oxygen, nitrate, pH, and Iron, and the distribution of fishes in station 2. Ogbo stream and its floodplain have low abundance and distribution of fish species. Therefore, it demands for sampling efforts and long-term studies to unravel the checklist of species.