Karyotypes of the Wild And Hatchery-Bred Parentals and the Intraspecific Hybrids of Clarias Gariepinus

This study presents the diploid chromosome number of Clarias gariepinus parentals from the wild and hatchery and their intraspecific hybrids. The kidney cells were used for the preparation of metaphase chromosome spreads. The diploid chromosome number for both parentals and hybrids was found to be 2n=56. The karyotypes for the wild parental revealed were 21metacentric, 1submetacentric, 2subtelocentric and 4telocentric and that of hatchery-bred parental revealed 23metacentric, 1submetacentric, 2 submetacentric and 2telocentric. The hybrids karyotype was 21metacentric, 2 subtelocentric and 5 telocentric for WH while HW had 19metacentric, 1subtelocentric and 8telocentric. The cytogenetic characteristics of both parentals and hybrids varied morphologically. This study provides information for hybridizations and possible manipulations of chromosomes in C. gariepinus, evolutionary study, classification and taxonomy and in monitoring aquatic toxicity. 

Keywords: Chromosome, Clarias Gariepinus, Karyotype, Hybrids, Mitotic Metaphase.