Heterobranchus spp. is a major freshwater fish that are widely distributed in Nigeria waters and are gaining rapid aquaculture expansion. However, indiscriminate artificial crossbreeding of the species with others poses a threat to their biodiversity. There is a paucity of information about the genetic variability, hence the need for variability insight for species conservation and aquaculture expansion. We tested the level of Genetic diversity, population differentiation and phylogenetic relationship on 35 individuals of two populations of Heterobranchus bidorsalis and 29 individuals of three populations of Heterobranchus longifilis using the mitochondrial cytochrome c oxidase subunit I gene sequence. Nucleotide sequences of 650 bp gene fragment of the species were compared. Four and five haplotypes were distinguished in the populations of H. bidorsalis & H. longifilis with accession numbers (MG334168 - MG334171 & MG334172 to MG334176) respectively. Haplotypes diversity revealed a range (0.59 ± 0.08 to 0.57 ± 0.09) in H. bidorsalis and 0.000 to 0.001051 ± 0.000945 in H. longifilis population. Analysis of molecular variance (AMOVA) revealed no significant variation among H. bidorsalis population of Niger & Benue Rivers, detected significant genetic variation was between the Rivers of Niger, Kaduna and Benue population of H. longifilis. Two main clades were recovered, showing separation between H. bidorsalis and H. longifilis. mtDNA COI genes fixation index (FST) statistics revealed high gene flow between populations with no distinct genetic differentiation. However, a proportion of population-specific haplotypes was observed with degree of genetic distinctiveness for each population. These results generated will help to protect the valuable wild resource and contribute to their recovery and selective breeding in Nigeria.
Keywords AMOVA, genetic diversity, Heterobranchus spp., mtDNA COI, phylogenetic tree
Themes: Genomic Applications in Aquaculture; Biodiversity Conservation in Aquatic Ecosystems