Erythrocyte characteristics of the progenies of pure and reciprocal crosses of Pangasianodon hypophthalmus (Sauvage, 1878) and Clarias gariepinus (Burchell, 1822)

In this study, erythrocyte characteristic of pure and reciprocal crosses of African catfish Clarias gariepinus (Burchell, 1822) and Asian catfish Pangasianodon hypophthalmus (Sauvage, 1878) were evaluated. Blood smear was made from the progenies of C. gariepinus (CG), P. hypophthalmus (PH), Pangapinus (♀PH × ♂CG) and in two morphotypes (Clarias-like and Panga-like) of Clariothalmus (♀CG × ♂PH) obtained from similar breeding history. Erythrocyte measurement of the cell and nuclear axis was done under the microscope, while many other parameters were calculated. Result obtained suggests a preponderant maternal influence on the erythrocytes shape and size characteristics of the reciprocal crosses. Erythrocytes from progenies with C. gariepinus maternal origin was rounded in shape (not less than 90%) while those with P. hypophthalmus maternal origin had relatively high oval shaped erythrocytes (between 76 and 64%). Also, significant size variations were recorded for the different group. Principal component analysis and biplot of component loading of the trio comparison of hybrid progenies and the pure crosses suggest the possibility of discriminating the direction of hybridization of the reciprocal crosses. However, it was impossible to describe the hybridization status of the progenies assessed in this study. This approach may be a simple and viable alternative to molecular markers which characterizes maternal inheritance in hybrid crosses provided that there is significant shape difference between the fishes. Erythrocyte characterization coupled with morphological and cytogenetic studies is recommended for clearer understanding of the nature of hybrid progenies.