Opisthobranchs of the Gulf of Mannar Biosphere Reserve, Tamil Nadu, India

The Gulf of Mannar, located in the south-east coast of India with an area of 10,500 km2 (l. 8o 47’ - 9o 15’ N and l. 78o 12’ - 79o 14’ E), is a major fishing zone in the Indian waters. Several fisher communities make their livelihood by exploiting finfishes and shellfishes as well as marine algae and other resources from this area. Extensive survey for sea slugs was conducted during 2008 in the sub-tidal regions of Vembar and Tuticorin groups of islands in the Gulf of Mannar Biosphere Reserve using SCUBA. The present study brings out 14 species of nudibranchs new to this region. Also one species each under both cephalaspidean and sacoglossan opisthobranchs described in the paper are new to this region. A total of 20 species of opisthobranchs were recorded during the study. Literature reveals that 47 species of nudibranchs have been recorded previously from the Gulf of Mannar region.