Research ArticleGenetic Relatedness of CI arias gariepinus (L.) from Cultured and Wild Populations Using Multivariate Analyses

摘要

Genetic diversity in germplasm is cardinal for breeders as it provides potential genotype (s) for breeding and improvement. Sixty C.gariepinus samples were obtained from the wild and cultured populations in Cross River, Nigeria. Twenty one morphometric traits were taken from each fish sample and were later prepared for proximate and mineral composition analyses. Predictive Analytics Software (PASW) version 20.0 was used for data analyses. Results showed that the standard length, pre-dorsal and pre-anal distances, pre-pectoral distance, head length, head width, eye diameter, distance between occipital process and caudal fin of C. garipeinus from the wild populations were significantly higher than those from the cultured populations. Calcium and magnesium contents were high in C. garipeinus from the wild populations while protein content was higher in the cultured C. garipeinus. The PC1 and PC2 contributed 44.89 and 14.00% to the total variability of 84.17%. From PCI, standard length (0.924), pre-dorsal distance (0.856), pre-anal distance (0.941), dorsal fin length (0.890), anal fin length (0.839), head length (0.946), head width (0.863), inter-orbital distance (0.820) and eye diameter (0.896) contributed significantly to the total variability observed in C.gariepinus populations. Cluster analysis revealed two major clusters for both morphometric and proximate composition, which were largely population-dependent. These suggest that C. gariepinus breeders and farmers should source C. gariepinus species from the wild in order to genetically enrich the gene pool. Additionally, head region-based morphometric traits might be more informative in distinguishing wild and cultured populations of C. gariepinus.