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                               Diodon  # Comments => Habit and Habitat: Diodon is confined to tropical seas, living along near reefs, caves, or ledges, hunting crustaceans and molluscs at night.  Diodon is commonly known as porcupine fish. Its body is rounded, globose, and covered with numerous flexible spines, the organs of defense; they are erected to protect the fish from any external enemy's attack. This fish can also inflate its body by swallowing water. The scales are generally spiny or bony. The caudal fin is rounded and tilted Upwards. The anal fin is opposite to the dorsal fin. There are 3 gills present. The belly is inflatable. The skin is leathery. Although porcupine fishes are poisonous, they are eaten as food fish and are an exotic delicacy in Japan and Indonesia.

                              Heteropneuptes # Comments => Habit and Habitat: It is found in rivers, estuaries, lakes, ponds, and ditches. They usually move in shoals.                                It is commonly called Singhi in Hindi. Its head is flattened and covered with thin skin. Flat snout with mouth and 4 pairs of barbels. The pectoral fin is quite strong with poisonous spines. The dorsal fin is short and without a spine. The anal fin is elongated and reaches up to the caudal fin but is separated by a deep notch. It has an accessory respiratory organ. Air bladder is also present. It is very popular as food fish and for its medicinal properties.

                              Echeneis  #Comments Habit and Habitat:   Echeneis is a common Marine fish. It swims in water feeding, on small fishes. It attaches itself through the adhesive disc to boats, sharks, bony fishes, sea turtles, and other marine animals.                                                       Echeneis are commonly called suckerfish. A sucking disc is found on the head. The first dorsal fin is modified into a suctorial disc for attachment. It is oval in shape and is provided with numerous transverse furrows Fish applies disc against other fishes thus creating a partial vacuum by operating the suction action. The second dorsal fin and anal fin are elongated and opposite to each other. The ventral fin has one spine. Caudal fin is bilobed. Commonly se...