Revealing Genetic Diversity of Clarias batrachus Using DNA Barcode

Abstract

Clarias batrachus is a species of freshwater catfish widely used for human consumption. Increasing demand of this species worldwide, coupled with its ability to survive in wide range of environmental conditions, has led to its introduction in many countries. This widespread translocation and distribution of C. batrachus have resulted in the rise of wide variety of haplotypes of this species. Nevertheless, there has been constant decrement in their population density in the last two decades. Thus, to endeavour conservation of the species we employ molecular technique of DNA barcoding in solving the standing problem of crypticism and haplotype sharing of the species. A better knowhow of the genetic makeup of the unique identifier region, that is, the 648 basepair region of COI DNA barcode will help to differentiate among closely related species and identify endemic species. In this study, a comparative analysis of C. batrachus from different regions in India and other parts of world shows presence of distinct haplotypes in different geographical locations. We also present a descriptive study of the various species of Clarias genus that have been barcoded in India till date. Our results also solve the dilemma of considering some species as synonymy of C. batrachus