Population Genetic Structure of Feral and Cultured African Catfish (Clarias gariepinus) inferred from Random Amplified Polymorphic DNA in Kano, Nigeria

Abstract

Information on the genetic structure of fish is a useful means for optimizing identification of stocks, stock enhancement, breeding programs, management of sustainable yield and preservation genetic diversity. The population genetic structure of African Catfish, Clarias gariepinus (Burchell, 1822) in cultured population and feral populations from Rivers Guzuguzu, Fada and Magaga (Kano State) were investigated using RAPD (Random Amplified Polymorphic DNA). Using a CTAB protocol, genomic DNA was extracted from the caudal peduncle of 157 samples of live specimen collected from each population. Five RAPD primers were used to amplify different loci on the extracted genomic DNA by Polymerase Chain Reaction (PCR) and the resultant DNA fragments were analyzed on agarose gel. A total of 406 reproducible bands were obtained in four populations for five primers. The dendrogram separated the four C. gariepinus populations into two distinct clades, Guzuguzu and Fada populations being in one clade, while Magaga and Cultured populations belonged to the other clade. The results based on RAPD-PCR profile ranged from 0.012 in Magaga/Cultured to 0.089 in Guzuguzu/Cultured. The genetic identity of C. gariepinus from four populations also ranged between 0.885 in Magaga/Guzguzu to 0.998 in Magaga/Cultured. The Nei’s genetic distance and identity also confirmed the above information with the following ranges: 0.002 in Fada/Cultured to 0.102 in Magaga/Guzuguzu, and 0.903 in Magaga/Guzuguzu to 1.000 in Magaga/Cultured respectively. In conclusion, the genetic diversity and allele richness of the feral and domestic fish populations were comparable.