First Record of the Genus Siphonaria Sowerby, 1823 (Mollusca: Gastropoda: Siphonariidae), an Associated Organism of Oyster from Coastal Zone of Sundarbans, West Bengal, India

The Sundarbans is bestowed with a wide range of natural forest and aquatic resources, offering the largest mangrove concentration with a great biodiversity and the only mangrove tiger-land in the world. A number of rare and endangered species have been recorded in this region. The Sundarban Biosphere Reserve is one amongst the three marine biosphere reserves in the country. The main objective of the marine biosphere reserve is protection, conservation and judicious utilization of the marine environment.