Which tuna species has the scientific name Thunnus thynnus?

The tuna species with the scientific name Thunnus thynnus is the Atlantic bluefin tuna.

Atlantic bluefin tuna are members of the mackerel family, Scombridae, and the genus Thunnus. Carl Linnaeus originally described the species in 1758 as Scomber thynnus; its accepted scientific name is now Thunnus thynnus.

This powerful, highly migratory fish inhabits the Atlantic Ocean and Mediterranean Sea. It is built for sustained speed and can maintain body temperatures above the surrounding water, an unusual ability among fish. Its dark blue back and silvery underside provide countershading in open water.

The Pacific bluefin tuna is a frequent source of confusion. It is a separate species, Thunnus orientalis. Yellowfin tuna is also different, with the scientific name Thunnus albacares, while bigeye tuna is Thunnus obesus. The repeated species name in Thunnus thynnus identifies the Atlantic bluefin specifically.