The Nuanai is a small river opening into the Bay of Bengal and has formed a small estuary of about 3 km long situated close to the temple town Puri, Odisha. As the estuary is very small the faunal diversity is very poor. The fishes, crustaceans and molluscs are the common elements. The random collections made during the study peribd of 2008-09 revealed the occurrence of 73 species of fishes under 53 genera belonging to 33 families. Mullet is the most dominant family represented by 9 speciesfollowed by leiognathids with 8 species, gerreids and tetradontids with 5 species each and rest of the families with three to one species. About 60 species are considered to be the food fishes, of which 27 species are commercially important and rest of them are having minor commercial value.
About 10 species of prawns under 4 genera belonging to 2 families, and 20 species of crabs under 15 genera belonging to 8 families are recorded. Five species of crabs namely Nanosesarma batavicum, Ocypode cordimana, Ocypode platytarsis, Dotilla myctiroides and Scopimera globosa are reported for the first time from the coast of Odisha. The mud crab, Scylla serrata, Portunus pelagicus, Portunus sanguinolentus, and the shrimps like Penaeus monodon, Penaeus semisulactus, Penaeus indicus, and Macrobrachium malcolmsonii are commercially important. The systematic account of all the species with diagnostic features and distribution is given. Over 70 colour photographs of the faunal elements are provided for easy identification.