Genetic diversity in snakeskin gourami ( <i>Trichopodus pectoralis</i> Regan, 1910): evaluating cultured and wild populations in Southeast Asia for breeding improvement programs

Assessing genetic diversity among potential populations provides crucial insights for genetic improvement programs targeting long-domesticated fish species. In this study, we evaluated genetic diversity levels using mitochondrial control region sequences of snakeskin gourami from one cultured and two wild populations (Ca Mau, CM and Kien Giang, KG) in the Mekong Delta, Viet Nam, alongside two other wild populations from Cambodia and Thailand. A total of 128 samples yielded 46 haplotypes, with five populations collectively contributing 42 unique haplotypes. All populations exhibited relatively high levels of genetic diversity, with haplotype diversity ranging from 0.719 to 0.877 and nucleotide diversity from 0.0075 to 0.0107. Statistically significant genetic differences were detected between the cultured and wild populations (<i>F</i>_ST range: 0.205-0.313), whereas weak genetic structure was observed among wild populations along the Mekong basin. These findings suggest that the cultured population holds potential as a base for genetic improvements, but crossbreeding between genetically distinct cultured and wild stocks should be carefully evaluated before large-scale seed production.