bluefin

Bluefin is a common name for three large tuna species in the genus Thunnus: the Atlantic bluefin tuna (Thunnus thynnus), the Pacific bluefin tuna (Thunnus orientalis), and the Southern bluefin tuna (Thunnus maccoyii). They are among the most commercially valuable tunas and are prized for their high-fat, flavorful flesh in sushi and sashimi.

Bluefin tuna are large, fast swimmers with streamlined bodies and a distinctive dark blue dorsal surface and lighter ventral side. They can reach weights of several hundred kilograms and undertake long-distance migrations across ocean basins, often crossing entire oceans to reach spawning or feeding grounds.

Their diet consists mainly of fish and squid, and they are apex predators in their pelagic ecosystems. They are highly migratory and form seasonal feeding aggregations, with spawning often synchronized with warm-season conditions in specific regions.

Commercial catch of bluefin tuna has been subject to international management due to concerns over stock depletion. ICCAT coordinates quotas and measures to rebuild stocks, though stock status varies by stock; some stocks have shown signs of recovery while others remain of concern.

In addition to capture fisheries, some southern bluefin tuna are raised in aquaculture operations to supply markets, though farming supplies are controversial due to feed and disease concerns. The term bluefin is also sometimes used colloquially to refer to bluefin tuna in general.