Genetic variation in Hilsa shad (Tenualosa ilisha) population in River Ganges

Abstract

enetic structure of the anadromous clupeid hilsa shad (Tenualosa ilisha) in Ganges was investigated using allozyme markers. A total of 26 loci are genotyped for samples collected during spawning period from five riverine locations viz. Brahmaputra, Padma, Ganga, Hoogly and Feeder canal. Despite the high level of polymorphism (31-50%, most common allele < 0.99), the samples from different locations do not exhibit significant genetic heterogeneity. The present results do not support earlier reports of the possibility of different races of hilsa in Ganges, but provide evidence for the existence of a single panmictic population. The observed homogeneity of allele frequencies is most likely to be explained by gene flow between the hilsa populations ascending different channels of Ganges.