Evaluation of Clarias gariepinus, Heterobranchus bidorsalis and Their Hydridsploidy

Résumé

This study investigated the chromosome numberof Clariasgariepinus, Heterobranchus bidorsalis, their hybrid C. gariepinus × H. bidorsalis and reciprocal hybrid H. bidorsalis × C. gariepinus. The chromosome preparation through mitotic cells stimulation, harvesting, fixation, and spreading were carried out following modification of the standard methods. Cytological examination confirmed the established karyotype ofC. gariepinus having 2n=56 while H. bidorsalis recorded 2n=52. Both hybrids revealed intermediate karyotype of 2n=54 as sum of haploid numbers of chromosome from the parents. The closeness of the chromosome numbers explains the successful hybridization even in nature. However, the aneuploidy of the hybrids suggests its non-suitability for breeding program for commercial purposes.