bluefish, (Pomatomus saltatrix), swift-moving marine food and game fish, the only member of the family Pomatomidae (order Perciformes). The bluefish ranges through warm and tropical regions of the Atlantic and Indian oceans, living in schools and preying with voracity on other, smaller animals, especially fishes. Elongated in form, it has two dorsal fins, a forked tail, and a large mouth with strong, pointed teeth. It is blue or greenish and grows to a length of about 1.2 metres (4 feet) and weight of 11.5 kg (25 pounds).