What Divers Should Know About Tuna

Found in warm seas, tuna are powerful pelagic fish often encountered in open water environments. This diverse group, belonging to the Thunnini tribe, comprises 15 species with a considerable size range. Bullet tuna reach a maximum length of 50 cm, while the formidable Atlantic bluefin tuna can grow up to 4.6 meters, commonly averaging 2 meters.

Built for speed, these active and agile predators are among the ocean's fastest swimmers; the yellowfin tuna, for instance, can reach speeds of up to 75 km/h. They possess a unique ability to maintain a body temperature higher than the surrounding water, a trait shared only with opah and mackerel sharks. Certain species, such as the Atlantic bluefin, are believed to live for up to 50 years. Their sleek, streamlined bodies are countershaded with metallic dark blue dorsals and silvery undersides, providing excellent camouflage in deeper water.