Tuna is a highly migratory species that can travel through thousands of miles of ocean throughout its life and is fished in diverse regions around the world. They are the only fish to maintain a body temperature higher than the water temperature. It belongs to the tribe Thunnini, a subgrouping of the Scombridae family. The Thunnini consists of 5 genera and 15 species. Of those, 8 species are considered “true tunas”, all which belong to the genus Thunnus.

Tuna ranges in size from the bullet tuna (max length: 50 cm or 1.6 ft, weight: 1.8 kg or 4 lb) up to the Atlantic bluefin tuna (max length: 460 cm or 15 ft, weight: 907 kg or 2,000 lb), which average 550 b in weight and 6.6 feet long.

Tuna has a sleek, torpedo-shaped bodies designed for speed and endurance. They have crescent moon-shaped tails and two dorsal fins on their backs, one of which can be flattened to reduce resistance in the water. Some species of tuna can swim as fast as 43 miles per hour.