Marine catfishes or fork-tailed catfishes are the common names used for the members of Ariidae family. They occur in saltwater, brackish, and fresh waters of tropical and subtropical oceans. They are mainly saltwater fishes that sometimes enter freshwater. Some species are only found in freshwater. They have forked caudal fin, 3 pairs of barbels (rarely 2 pairs), and bony plates on head and near dorsal fin. They have 3 long, hard, usually serrated spines on their dorsal and pectoral fins. These spines are venomous but not lethal.
Marine catfishes are bottom-living fishes found in mangrove areas, large river estuaries, and turbid waters, as well as in fully marine waters and clear fresh waters. Some of them are omnivorous and some feed on small fishes, molluscs and crustaceans.
There are 30 genera and more than 147 species of Ariidae worldwide. Malaysia has 11 genera and about 25 species, with 3 species that enter freshwater.