A molecular analysis of selected marine fishes from the southwest coast of India for species delineation

Abstract

In this study, mitochondrial genes 16S and cytochrome C oxidase I (COI) were used as taxonomic markers for the molecular analysis of selected fishes from the southwest coastal waters of India, viz., Sillago sihama (Forsskål, 1775), Mene maculata (Bloch & Schneider, 1801), Seriolina nigrofasciata (Ruppell, 1829), and Minous dempsterae (Eschmeyer, Hallacher & Rama-Rao, 1979). Both the gene fragments showed diagnostic differences and divergence within each taxon. The mean nucleotide diversity (Pi) among all the species was estimated as 0.083. The average transition and transversion ratio was 1.63. The average K2P distance of species within genera was estimated as 13.71 %, whereas it was 20.22 % among species within families. The variation was more among the species within families than among the congeneric individuals. The study on the phylogenetic relationships among the species revealed distinct clusters in concurrence with the taxonomic status of the species. The study also suggests that the mtDNA 16S (rRNA) and COI genes can be used as barcodes for the identification of fish species based on sequence information.