Contemporary and historic patterns of intraspecific diversity in Indian anchovy, Stolephorus indicus, from Indian peninsular waters

Abstract

We analyzed intraspecifc diversity of Indian anchovy, Stolephorus indicus, a commercially and ecologically important species, using mitochondrial DNA markers so as to derive insights into population structuring and historical demography. Analyses were carried out on 128 and 138 individuals collected from 5 locations along the range of distribution using mitochondrial ATPase (843 bp) and COI (663 bp) sequences respectively. Signifcant connectivity and gene fow was detected among fshes collected from all the geographic locations as indicated by lack of structuring in Bayesian clustering analysis along with insignifcant ΦST values. Oceanographic features of the Bay of Bengal, Arabian Sea and Andaman Sea may be favorable for the dispersal of anchovy larvae and subsequent gene fow. Historical demographic analyses indicated a demographic and spatial expansion taken place approximately during 125,000 years before present, the Pleistocene epoch. Indian Ocean witnessed emergence of upwelling events and consequent increase in productivity during the Pleistocene epoch causing a demographic and spatial expansion of anchovies. Management measures for this species should be devised considering it as a single stock along its entire range of distribution.