Atlantic bluefin tuna.

Where to find it.

The Atlantic and the Mediterranean; main spawning grounds in the Mediterranean and the Gulf of Mexico.

Also known as Bluefin, Tunny.

A closer look.

Spindle-shaped body, round in cross-section, with a crescent tail and a row of small finlets behind the dorsal and anal fins. Dark blue back, silver flanks.

How it lives.

A counter-current heat exchanger in its blood vessels (the rete mirabile) lets the bluefin keep its muscles well above water temperature, so it can hunt in cold seas.

The next generation.

Spawns in late spring and summer in warm water. Large females release millions of free-floating eggs.

Conservation

After a steep decline from overfishing, strict quotas set by ICCAT allowed the stock to recover. In 2021 the IUCN moved the species from Endangered to Least Concern.

Least Concern — global IUCN assessment dated 15 January 2021. Regional populations can have a different status. View the Red List record ↗

In the margins.

• The rod-and-reel record, about 679 kg, was caught off Nova Scotia in 1979.
• In 2019 a 278 kg bluefin sold at auction in Tokyo for 333.6 million yen.