Study Area: Mangrove molluscs were sampled between (June to July 2011) from pazhayar back water canal (Lat,
110 21' 14. 61' N; Long, 790 49' 28. 17' E) southeast coast of India (Fig. 1). It is free connected canal with mouth
region at coleroon estuary. The two mangroves species of Avicenia sp and Rhizophora sp were planate for 0.5
hectare around the back water canal, after Tsunami.