How many species of tuna are there?

The Thunnini tribe comprises 15 species across five genera.

How big can tuna get?

Tuna sizes range from about 50 cm and 1.8 kg for bullet tuna up to 4.6 m and 684 kg for Atlantic bluefin tuna, which averages around 2 m.

Can tuna regulate their body temperature?

Yes — tuna, along with opah and some mackerel sharks, can maintain a body temperature higher than the surrounding water.

Are tuna fast swimmers?

Yes — tuna are among the fastest-swimming pelagic fish; yellowfin tuna can reach speeds up to about 75 km/h (47 mph).

Why are some tuna species threatened?

Extensive commercial fishing has led to overfishing, putting some species such as southern bluefin tuna at risk.

Where are tuna typically found?

Tuna are found in warm seas and occupy pelagic (open-water) habitats.

Saltwater Fishes

Tuna

Q: Are tuna targeted by fisheries and anglers?

Yes — tuna are widely commercially fished for food and are popular as bluewater game fish.

Tuna are streamlined, fast-swimming pelagic fish in the Thunnini tribe found in warm seas and widely fished for food and sport.

tunas

Last Updated Mar 9, 2026 · 2 sources

Species Guide

What to know about tunas

A clean field guide focused on habitat, identification, behavior, and conservation context without burying the useful parts.

Tuna belong to the tribe Thunnini within the mackerel family Scombridae and comprise 15 species across five genera. Sizes vary greatly, from bullet tuna (about 50 cm and 1.8 kg) to Atlantic bluefin tuna (up to 4.6 m and 684 kg; averages around 2 m and may live up to 50 years). Tuna are active, agile predators with sleek, streamlined bodies and are among the fastest-swimming pelagic fishes; yellowfin tuna can reach speeds up to 75 km/h (47 mph). Tuna, opah, and certain mackerel sharks are among the few fishes capable of maintaining a body temperature higher than the surrounding water. Found in warm seas, tuna are extensively commercially fished for food and are popular as bluewater game fish. Overfishing has put some tuna species, such as southern bluefin tuna, at risk of extinction.

Some tuna species have been driven toward extinction risk due to extensive commercial fishing and overfishing.

Pelagic, active and agile predator; among the fastest-swimming open-ocean fishes, capable of short bursts at high speed.

The strongest linked planning options currently surface around destinations such as Fuvahmulah, Puerto Princesa + Tubbataha Gateway (Palawan), Togean Islands and Tomini Coast and countries such as Indonesia, Maldives, Egypt for divers building trips around tunas.

Identification

How to identify tunas

The visual markers divers can use underwater, plus the species most likely to cause confusion.

Key identification markers

Body shape

Sleek, streamlined body adapted for fast, sustained swimming in open water.

Size range

Species vary greatly in size, from around 50 cm and 1.8 kg up to several meters and hundreds of kilograms.

Warm-water habitat

Found in warm seas, occupying pelagic, bluewater environments.

Endothermy

Able to maintain a body temperature higher than the surrounding water (shared with opah and some mackerel sharks).

Range and Movement

How tunas move through the world

The broad range, seasonal movement, or migratory behavior that shapes where divers encounter this species.

Pelagic, active and agile predator; among the fastest-swimming open-ocean fishes, capable of short bursts at high speed.

Diet

What tunas tend to eat

Useful feeding context that often explains habitat, movement, and encounter style.

Active predator (specific prey items not detailed in source).

Conservation

What is happening with Tunas

Status, pressure, and protection context grounded in cited sources rather than filler.

Some tuna species have been driven toward extinction risk due to extensive commercial fishing and overfishing.

Main threats

Overfishing

Extensive commercial fishing for food and sport has caused declines in some tuna species, leading to threat status for species such as southern bluefin tuna.

Responsible Encounters