This study was designed to evaluate morphological variations of cichlids from the Kainji lake, Niger State in Nigeria. 200 samples of cichlids comprising four species (Oreochromis niloticus, Tilapia zilli, Pelmatolapia mariae and Sarotherodon galilaeus) were collected from the lake and a total of thirty morphometric measurements and meristic counts were recorded. Data was corrected to eliminate size effect on sample and subjected to discriminant function analysis to determine rate of divergence among species. Results obtained revealed significant variation in some morphometric parameters measured and all six meristic counts recorded. Growth pattern revealed negative allometric growth for O. niloticus (2.29), T. mariea (0.72) and S. galilaeus (2.47) while T. zilli, had a positive allometric growth. Discriminant analysis showed some levels of overlap across species for both morphometric measurement and meristic count. Interspecific distance was closest between T. zilli and O. niloticus (14.70) while the farthest distance was recorded between T. zilli and S. galilaeus (52.40). The observable overlap among species despite morphometric and genetic differences may have been as a result of similar species adaptations in response to the prevailing environmental conditions.
Keywords: Lake, Man Made Lake, Meristic Count, Morphometric Parameters, Tilapia
