Assessing impact of dams on genetic diversity of native fish Mastacembelus armatus in river Yamuna using mitochondrial DNA cytochrome-b sequences as a molecular marker

Abstract

Several dams have been constructed in Uttarakhand. In the present study an investigation on impact of dams on genetic diversity of native fish species Mastacembelus armatus at the Asan barrage on river Yamuna near Vikasnagar, Uttarakhand in India was done. Partial sequence of mitochondrial Cytochrome-b (Cyto-b) gene was used to determine the genetic variation in the population of Mastacembelus armatus. DNA was extracted from Mastacembelus armatus (n=33) samples, collected from river Yamuna and its tributary Asan from fin and fishes were released back in their habitat. Cytochrome c oxidase I (COI) was used to ascertain the species of fish along with morphometric characters. Analysis of 324 bp mtDNA fragment of Cyto-b revealed the presence of 06 haplotypes with nucleotide diversity, value ranged from 0.0172 to 0.0021 low pair wise Fst value was observed negative (-0.00125) when compared between Asan barrage and Kalsi site. No genetic subdivisions between the population were found after or before the dam sites. Tajima’s D value for river Asan, site A1 Mirzapur (before dam) was -0.1167 (a negative value). Negative Tajima D value can be indicative of recent selective sweep or population expansion after a recent bottleneck and linkage to a swept gene. Our data shows that fragmentation of habitat by dams does not have any impact on the genetic diversity of non-migrating Mastacembelus armatus fish species.