1. Any very large marine food and game fish of the genus Thunnus; related to mackerel; chiefly of warm waters; SYN. tunny.
2. Important warm-water fatty fish of the genus Thunnus of the family Scombridae; usually served as steaks; SYN. tuna fish, tunny.
3. New Zealand eel; SYN. Anguilla sucklandii.
4. Tropical American flat-jointed prickly pear; Jamaica; SYN. Opuntia tuna.
Any of various large marine bony fishes of the mackerel family, especially the genus Thunnus, popular as food and game. Albacore t. alalunga, bluefin tuna t. thynnus, and yellowfin tuna t. albacares are commercially important.
Tuna fish gather in shoals and migrate inshore to breed, where they are caught in large numbers. The increasing use by Pacific tuna fishers of enormous driftnets, which kill dolphins, turtles, and other marine creatures as well as catching the fish, has caused protests by environmentalists; tins labeled “dolphin-friendly” contain tuna not caught by driftnets. Thailand is a major tuna-importing and canning country.
Overfishing is causing a reduction in tuna stocks around the world. In spite of the introduction of quotas in Australia in the 1980s, the country's catch of southern blue-fin tuna 1990–91 was 5,000 metric tons—the lowest since 1962, and the species could be in danger of extinction. Tuna stocks in the Atlantic declined by almost 90% during 1970–92.