Genetic diversity and population structure of Barilius barna (Hamilton, 1822) in the sub-Himalayan Dooars region of West Bengal, India through Mitochondrial Cytochrome Oxidase I Sequence analyses

The genetic diversity and the population structure of Barilius barna (Hamilton, 1822) wild population from the Teesta River were assessed through mtDNA cytochrome oxidase I (COI) sequence analyses. The haplotype and nucleotide diversity analyses revealed low level of genetic diversity in the B. barna wild populations, especially in the lower reaches of Teesta (Bholarhat). The genetic differentiation and gene flow between the two study sites were 0.08434 and 2.71, respectively. Tajima’s D, Fu and Li’s D and Fu and Li’s F analyses were used to assess population differentiation in the two study sites. Haplotype networking and phylogenetic analyses clearly distinguished the two populations from each other, as well as from other populations from other parts of the country. Nature and implications of the genetic and haplotype diversities among the populations are discussed. Phylogenetic analyses also indicated that the Gajoldoba population is genetically closer to north Indian river populations, than that to Bholarhat population.