Morphological characterization of natural populations of Sarotherodon galilaeus (Linnaeus, 1758) from three selected reservoirs in South Western, Nigeria

Morphological characterization of Sarotherodon galilaeus (Linnaeus, 1758)from Opa, Asejire and Ero reservoirs in southwest, Nigeria was carried out with a view to determining the morphological heterogeneity or homogeneity among the three different populations and to determine whether there are morphotypes of this species in the selected study areas. Twenty five morphometric measurements and six meristic counts were recorded on 150 specimens; fifty from each reservoir population. Principal Component Analysis (PCA) and Canonical Variate Analysis (CVA) were performed on the morphometric and meristic data using PAST software. All the clusters produced by the PCA and CVA analyses on the morphometric and meristic data overlapped widely; indicating a low level of morphological differentiation among the three populations of Sarotherodon galilaeus. The study concluded that the Sarotherodon galilaeus populations from Opa, Asejire and Ero reservoirs are morphologically similar and phenotypically inseparable. Keywords: Morphometric, Meristic, Morphological differentiation, Reservoirs in south-western Nigeria, Sarotherodon galilaeus