Mitochondrial DNA markers reveal stock composition and genetic diversity of Ompok bimaculatus: a valuable resource for aquaculture diversification

Genetic diversity and population structure are essential aspects for understanding the evolutionary history, conservation as well as species diversification in freshwater aquaculture. This study aimed to investigate the genetic variation and population structure of Ompok bimaculatus, commonly known as the butter catfish, using mitochondrial DNA markers, i.e., cytochrome b and ATPase 6/8 genes, as well as their concatenated sequences. The Cytochrome b, ATPase 6/8 and combined genes revealed a large number of haplotypes and low nucleotide diversities. AMOVA results indicated a high level of variance, attributed to differences within populations with significant F_ST values and the presence of population structure in natural populations. High levels of genetic differentiation within populations of O. bimaculatus were observed. Population-specific haplotype highlighted genetic differentiation among the four studied natural populations, which indicated the presence of distinct genetic characteristics within each population. Molecular variance analysis and pairwise F_ST values based on cyt b (F_ST: 0.02227 to 0.58236), ATPase 6/8 (F_ST: 0.000 to 0.28410) and concatenated (F_ST: 0.00504 to 0.41511 (Gomti-Kaveri)) further confirmed the genetic differentiation and population structure. The findings of this study provide valuable insights into the species’ genetic characteristics, which can aid in the development of targeted conservation strategies to preserve genetic diversity and ensure the long-term viability of O. bimaculatus populations.