New records of sharks (Elasmobranchii) from the Andaman and Nicobar Archipelago in India with notes on current checklists

Abstract

The diversity of sharks occurring off the Andaman and Nicobar Archipelago in India has received increased attention in recent years. Yet, available checklists are out of date, often with inaccurate information and a number of commercially important species have not been documented through research and fish landing surveys. Here we report on shark species examined during fish landing surveys conducted from January 2017 to March 2018. Records of twelve previously unreported species from the archipelago are presented and include the bignose shark (Carcharhinusaltimus), pigeye shark (Carcharhinusamboinensis), bull shark (Carcharhinusleucas), snaggletooth shark (Hemipristiselongata), slender weasel shark (Paragaleusrandalli), Arabian smoothhound shark (Mustelusmosis), Indonesian houndshark (Hemitriakisindroyonoi), sand tiger shark (Carchariastaurus), Indonesian bambooshark (Chiloscylliumhasseltii), tawny nurse shark (Nebriusferrugineus), dwarf gulper shark (Centrophorusatromarginatus), and the Indonesian shortsnout spurdog (Squalushemipinnis). These records increase the reported shark species for the archipelago from 47 to 59 and for India from 114 to 116. Additionally, a size extension in the total length ofC.hasseltiiby 27 cm and ofP.randalliby 8 cm is reported. Owing to the bio-geographical location of these islands, species diversity around the archipelago is unique and appears to overlap with that of southeast Asia. With increasing reports of over-exploitation and the operation of a targeted shark fishery by distant water fleets in these waters, the limited information on shark diversity from this region is of concern. Systematic and long-term monitoring of catches, combined with accurate species identification, is crucial to provide information on management measures.