Morphological differentiation in African catfish (Clarias gariepinus) from three different populations in Nigeria

AbstractIntraspecific morphological variation in Clarias gariepinus was studied in three water bodies. Twenty-three morphometric characteristics and seven meristic were used. Principal component (PC) analysis showed that morphometric traits of River Osun and Ogbese were somewhat related while that of Aago showed no relatedness, there were no difference among the meristic counts of the populations. PC1, and PC2 accounted for 93% and 4% of the variation observed in the populations. High positive correlation was observed in Aago (r = 0.872, b = 2.10) and Ogbese population while low correlation and negative allometric growth (r = 0.425 and b= 1.38) was observed in Asejire population. Cluster analysis revealed that three studied populations are separated into two major clusters, with samples from Asejire and Ogbese population found within the same cluster but different sub- clusters, similarly some of samples from Aago were also within the same cluster while samples 10 were found on a separate and major cluster. The study confirms the variability among individual species within each population, indicates the presence of genetic diversity among the populations of C. gariepinus and the Pre-anal distance and dorsal fin ray count could be employed in the identification of populations of catfish. Key words: morphometric traits, meristic characters, populations, allometri