Record of a Critically Endangered Dasyatid Ray Maculabatis arabica (Dasyatidae) from the East Coast of India

Taxonomy of sting rays shows an interesting puzzle to be solved since many members of family Dasyatidae are morphologically indistinguishable and a large variation exists with growth. This morphological ambiguity requires molecular studies for identification of species. Morphological identification backed by mtDNA COI gene barcoding demonstrated the occurrence of the Critically Endangered plain-coloured species, Maculabatis arabica (Pakistan whipray) for the first time along mid-eastern coast of India (Odisha and Andhra Pradesh). Maculabatis arabica is a plain brown coloured stingray characterized by absence of white spots at its tail base, one to three large, seed shaped mid-scapular denticle with absence of a primary denticle band and an incompletely banded tail with a black distal caudal region. DNA barcoding of the COI gene segment resulted in confirmation of this taxonomically ambiguous species which is often confused with its congener M. gerrardi. Since immature individuals were observed in this study, continuous exploration should be carried out to confirm the presence of adult population along the coast. The present study has major implications on the threatened category of M. arabica since this study confirms the occurrence of M. arabica throughout the Northern Indian Ocean. The study also throws light on the rich elasmobranch faunal assemblage in Bay of Bengal and provides motivation to carry out future exploratory studies with a focus on mapping the occurrence of endangered elasmobranch species.