ECOBIOLOGICAL STUDY ON BURROWING MUD LOBSTER THALASSINA ANOMALA (HERBST, 1804) (DECAPODA : THALASSINIDEA) IN THE INTERTIDAL MANGROVE MUDFLAT OF DELTAIC SUNDARBANS

Populations of mud lobster Thalassina anomala were studied on tidal flats in the Sagar island of Indian Sundarbans. Ecologically they are recognized as the 'friends of mangrove' and a 'Biological Marvel' of the system. They turn up the deep soil to the surface by regular night shift burrowing exercise and help to import aerated tidal water in the burrows 2 to 2.5 meter deep. They have extra ordinary morphological adaptation and structural changes and completely resort to detritivore diet. Being thigmotactic it seldom exposes to atmospheric oxygen and forms its palace underground with a central chamber having 5 to 6 radiated tunnels opening to the surface covered with earth mounds. It displays its engineering skill of bioturbation in tunneling. During tunneling the shrimp feeds on the mud packed with detritus and derived its required micronutrients. Being mud dwelling and mud eating habits, it's respiratory and food manipulating apparatus underwent transformations which demands intensive investigation. Thalassinid burrow associates comprising mieo and microorganisms also provide good subject of study of species specific interaction, exchanging of materials between associate partners.