Puffer Fish (patka machh) a balloon-shaped fish of the family Tetradontidae, order Tetraodontiformes. The fish is able to inflate itself enormously with air like a balloon, and are found both in freshwater and marine environments. Though Patka is eaten in some places in the southern districts after cooking in a special way, the fish has poisonous effects, and occasional deaths have been reported. Three species under two genera are found in Bangladesh.
Green Pufferfish (Chelonodon fluviatilis) is slightly compressed bodied, attains a length of about 12 cm with broad head and back, tapering abruptly to tail. Upper part of the body is olive green; sides and lower part white; there are black blotches on the back and sides. The fish is found in rivers and estuaries. Gangetic Pufferfish (C. patoca) has a nearly cylindrical body, attains a length of about 8 cm, head broad, body brown or black; sides and abdomen silvery; there are oval and round spots on the upper part. The fish is found in the estuaries and in the Bay of Bengal.
Ocellated Pufferfish (Tetradon cutcutia) has broad head and back, tapering abruptly at the tail. Upper part of the body greenish yellow, abdomen white. The fish is found widely in the freshwater throughout the country. The fish is not commercially important. [Nashida Banu]