Genetic Structure of the Dutch Domesticated Clarias Gariepinus Cultured in Nigeria

Abstract

The sharptooth catfish, Clarias gariepinus is the most cultured fish in Nigeria. The animal is native to Africa. It was selected for growth in The Netherlands from where the Dutch strain was introduced to Nigeria. To examine the genetic variation among the strains in Nigeria, part of the cytochrome b gene from 71 individuals was sequenced. Haplotype diversity varied from 0.333 - 0.689 while the nucleotide diversity varied from 0.000 – 0.1738. The result reveals 3 distinct mtDNA lineages, which are highly divergent from each other. The nucleotide difference between the native strain and the Israeli and Central African populations are in the magnitude of 1.44 – 3.26%. These strains belong to different highly genetically distinct and divergent populations and should not have been mixed.

Key Words: Exotic Clarias gariepinus, North Africa catfish; mitochondrial DNA polymorphism; cytochrome b