The wetlands eco system are considered as among the richest areas of bio diversity. Pulicat, by virtue of the mixing of fresh water with sea water is found to be an ideal habitat for diverse life-forms. 160 species of fish, 25 species of polychaete worms, 12 species of prawn, 19 species of mollusk and 100 speceis of birds are well documented apart from a number of other aquatic flora and fauna.
Among the most spectacular is the flamingo-a tall gaunt, white-coloured bird with a touch of pink on the wings, pink beak and legs, seen feeding in shallow water. The squat, large-billed grey pelican with gular pouch and a number of ducks are commonly seen. Flocks of sea gulls and terns circling in the sky or bobbing up and down on the water are an added attraction at pulicat. Besides, there are a number of waterside birds and waders such as curlews, stilts, plovers, sand pipers, lapwings, redshank. Egrets, herons, kites etc. are some other birds found here. The lake is also home to crabs, clams, mussels, oysters, snails, fish worms, insects, spiders, sponges, anemone, prawns, plankton and so on