Tuna

Tuna are saltwater fish belonging to the tribe Thunnini, a subgrouping of the mackerel family, comprising 15 species across five genera that range in size from the bullet tuna, at a maximum length of about 50 centimeters, to the Atlantic bluefin tuna, which can reach 4.6 meters and 684 kilograms and live up to 50 years. Tuna, opah and mackerel sharks are the only fish able to maintain a body temperature higher than the surrounding water, and as an active, agile predator the tuna has a sleek, streamlined body and is among the fastest-swimming pelagic fish, with the yellowfin tuna capable of speeds up to 75 kilometers per hour. Found in warmer seas, tuna is commercially fished extensively as a food fish and is also popular as a bluewater game fish.