Morphological Diversity of Wild Populations of Sarotherodon Melanotheron Rüppell, 1852 of Southern Benin

Abstract

The establishment of morphological identity of a species in differently located waterways is very important in the use of its fishery resources in breeding programs. This work aims to analyse the morphological parameters of native populations of Sarotherodon melanotheron in relation with their waterway of origin, hydrobiological period and sex. Most of the sampled fishes has sizes ranged between 05 and 15 cm with 57.66%, 31.85%, 36.62% and 22.19% respectively in Grand-Popo lagoon, lake Nokoué, Ouémé river and lake Toho. Outside of the body height, prepelvic length and anal-fin base length, all the other metric parameters varied significantly from a waterway to another (p<0.05). For both females and males, the relative growth coefficients (b) varied from 1.74 to 3. The condition factor (K) varied from 1.81±0.37 to 1.88±0.42 and 1.79±0.29 to 1.87±0.36 respectively for males and females and did not vary significantly according to the sex (p>0.05). Metric variables were more discriminative than meristic counts. Two populations are differentiated: the first constituted by individuals of Ouémé river and lake Nokoué and the second represented by individuals of Grand-Popo lagoon and lake Toho. Molecular prospectings are necessary to clarify the diversity of this fish.