Identification and Reappraisal of Epinephelus coioides and Epinephelus tauvina through a DNA Barcoding Approach from the Andaman waters

Abstract

Present study consists sequencing of Cytochrome Oxidase I gene (COI) (DNA barcoding) to identify Epinephelus coioides (Hamilton, 1822) and Epinephelus tauvina (Forsskal, 1775)specimens. Using a Kimura two parameter (K2P), Neighbour Joining (NJ) phylogram and species identification found in the Barcoding of Life database (BOLD) revealed that Andaman species of E. coioides and E. tauvina has low genetic divergence indicating that they may in fact belong to the same species despite, earlier conventional taxonomy reporting the existence of E. coioides and E. tauvina in Andaman waters. In addition, COI gene sequences (many from voucher specimens) retrieved from public databases such as NCBI and BOLD for the comparative and real genetic identity was done. The COI gene sequence used for the K2P analysis delineated species studied in Andaman (E. coioides and E. tauvina ) and Indian references (E. tauvina) sequences had intraspecific genetic divergence values of 0.005 and NJ phylogram showed that these two species are one and same in Andaman waters as well as Indian reference sequences. Based on the morphological study of Andaman water species it showed two different species but the internal organelle (pyloric caeca count) study exhibited as a single species, i.e. E.coioides. The present study concluded that DNA barcoding sequence provides the distinct genetic distances among studied Epinephelus species with low level of interspecific genetic distances for E. tauvina and E. coioides. Present study concluded that the Andaman water groupers need reclassification or re-evaluation in future.