A 307 bp segment of Cytochrome b gene of mtDNA was sequenced and analyzed for 90 individuals of Cirrhinus mrigala collected across the three rivers, namely Ganges, Narmada and Brahmaputra. Analyses revealed the presence of 14 haplotypes with haplotype diversity (h) ranging from 0.304 to 0.692, and nucleotide diversity (π) 0.002-0.043. The majority of variation was found within the population (96.21%), and the FST value (0.035) as well as the value of exact test of population differentiation (0.893) were found to be insignificant (p<0.05). Analysis of molecular variance (AMOVA) also indicated insignificant differentiation among sub-populations. Generally, low genetic differences were observed even though those populations were from different geographic locations. The present study suggests a single panmictic population of C. mrigala across the three rivers of India.
Keywords: Cirrhinus mrigala; Cytochrome b; Indian rivers; genetic differentiation.