First report on the use of gastropod shells by hermit crabs from the eastern coast, India

The assemblage of different crab species in the shoreline ecotone region are potential indicators for maintaining structural and functional integrity of the coastal ecosystem. The hermit crabs among the different crab species of this habitat is notable for understanding the intrinsic relationship of the crab dependence on gastropod shells which is important to explain the shell use pattern in nature. Random sampling of specimens was done from the intertidal zone of extended mud flats of Bakkhali and Frazerganj of Indian Sundarban for a period of one year, which showed greater availability of one type of gastropod shell Telescopium telescopium. Twenty one different types of gastropod shells were chosen by Clibnarius infraspinatus and Clibnarius padavensis as their microhabitat, among which later shows greater affinity for Telescopium shells. The statistical analysis showed that the crab weight and shell weight are positively correlated at a significant level (p< 0.01). Present communication also suggests preference of microhabitat selection by hermit crabs depends on various factors like, spatial distribution and availability of resources, durability of the shells, inner columellar space, coiling of shells and association of epibiotic covering of the shells (scallops and barnacles).