DNA barcoding and preliminary phylogenetic analysis of few gastropods (Family: Potamididae and Nassariidae) in Vellar estuary mangroves, India by COI and 18S rRNA genes

Abstract

Class Gastropoda is one of the widely studied invertebrates throughout the globe. But, even now most of the species have been identified only by conventional morphology. DNA barcodes have been greatly useful to delimit the cryptic species. In this study, we have analyzed cytochrome c oxidase I (<em>COI</em>) and <em>18S</em> <em>rRNA</em> gene sequences from 12 specimens belonging to four species to barcode and examine the molecular variation in gastropods of the Vellar estuary mangroves of Tamil Nadu, India. From the results, it is revealed that, among the four genera, <em>Terebralia, Telescopium, </em>and <em>Cerithidea</em> are closely related than genus <em>Nassarius</em> based on the <em>COI</em> and <em>18S rRNA</em> gene sequences. The neighbour joining trees also confirmed four distinct clades harbouring four genera. As expected, the within species K2P genetic variation is lesser than between species K2P genetic variation in both the genes. An intensive survey is needed to assess the genetic variation of all gastropods in the manmade Vellar estuary mangroves and nearby natural Pichavaram mangroves with additional molecular markers.