Comparative genetic and morphometric characterization of sympatric populations of Heterobranchus bidorsalis and Heterobranchus longifilis

Résumé

African catfish species of Heterobranchus longifilis and H. bidorsalis are gaining breeding potentials and receiving great attention among catfish stakeholders. However, very few comparative research works have been done on the natural populations and cultured stocks of these economically important species. In this study, the genetic evaluation of the fish species populations obtained from Lake Kainji, New Bussa, Niger State, Nigeria, was conducted through Sodium Dodecyl Sulphate - Polyacylamide Gel Electrophoresis oftheir serum proteins, and morphometric evaluation. Morphometric data showed that adipose fin attributes [length; depth (cm), % standard length (SL)] of 23.4±1.1; 4.2±0.5 in the H. bidorsalis confirmed its hyper-development compared to H. longifilis of 25.7±3.2; 4.4±0.6 respectively. The pre-dorsal length gave higher value (%SL) in the H. longifilis (38.6±2.2) than H. bidorsalis (34.6±1.2); while H. bidorsalis further possessed more counts at dorsal and anal fin rays than H. longifilis. The comparative dendrogram of the PAST analysis showed a genetic distance of 4.2% that indicated the specificity of these species and, though significantly different, they had very close relationship. Therefore, proper identification of these species is highly necessary to maintain genetic purity in breeding programmes and biodiversity.