Metric and meristic characterization of Orechromis niloticus (Linnaeus, 1758) populations in the Mono, Oueme, and Volta River bassins in Bénin.

Abstract

A total of 222 fish specimens were collected for the characterization of Oreochromis niloticus populations of the Oueme, Mono, and Volta river basins in Benin. The main objective was to determine the number of strains therein, with the goal of taking a sample of living subjects and then to identify from these, upon a series of experimentations in controlled environments, the most efficient strain to be used in aquaculture. The fishes used were collected from May to September 2016 from lakes located in the Mono basin (Toho, Togbadji, and Nangbeto lakes), in the Oueme basin (lake Gobe), and from the Pendjari River in the Volta basin. On each individual, nineteen metric and six meristic characteristics were used. The results show that, in the Mono basin, the Togbadji fish populations differ from those of the Toho, Gobe and Pendjari. Toho fish populations are distinguished from those of Gobe and Pendjari. From these results, four different populations are to be distinguished in the three basins we have explored: the Mono population, the Oueme population, and the Volta population. ???? Keywords: Cichlidae, Oreochromis niloticus, morphometric,