Species assemblage in the coral reef ecosystem of Netrani Island off Karnataka along the southwest coast of India

Netrani is an uninhabited island located nearly 18 km off Murdeshwar (Karnataka State) in the southwest coast of India (1402' N lat; 7433' E long.). So far the coral reef ecosystem around this island has not been reported in scientific literature. Therefore, an underwater visual census of the coral reef was undertaken in May 2006 by SCUBA diving. The survey has revealed the existence of a patchy reef surrounding this island consisting of 14 coral species belonging to 11 genera. Other flora and fauna comprised of fishes (92), seaweeds (7), sponges (6), jellyfish (2), holothuria (1), nudibranchs (7), zooplankton (25), bivalves (15), phytoplankton (16), gastropods (48), cephalopods (3), crabs (17), shrimps (2), lobsters (4), etc. Twenty-six species of fishes recorded from this island reef area were found to be new records from the Indian coast. Two IUCN Red Listed fish species, the humphead wrasse (Cheilinus undulatus) and the whale shark (Rhincodon typus) were recorded from the island area. Another IUCN red listed mollusc, the giant clam (Tridacna maxima) was found inhabiting this reef and this is a first report on the occurrence of this species from the mainland Indian waters. The Indian Navy based at Karwar uses the Netrani Island as target for shooting/shelling practice and evidence of the same was observed during the survey. The wealth of biodiversity around this reef emphasizes the need to conserve and preserve it.