Population genetic structure of Indian shad, Tenualosa ilisha Inferred from variation in mitochondrial DNA sequences

Indian shad, Tenualosa ilisha, is a commercially important anadromous fish representing major catch in lndo-pacific region. The present study evaluated partial Cytochrome b (Cyt b) gene sequence of mtDNA in T ilisha for determining genetic variation from Bay of Bengal and Arabian Sea origins. The genomic DNA extracted from T ilisha samples representing two distant rivers in the Indian subcontinent, the Bhagirathi (lower stretch of Ganges) and the Tapi was analyzed. Sequencing of 307 bp mtDNA Cytochrome b gene fragment revealed the presence of 5 haplotypes, with high haplotype diversity (Hd) of 0.9048 with variance 0.103 and low nucleotide diversity (pi) of 0.14301. Three population specific haplotypes were observed in river Ganga and two haplotypes in river Tapi. Neighbour-joining tree based on Cytochrome b gene sequences of T. ilisha showed that population from Bay of Bengal and Arabian Sea origins belonged to two distinct clusters.