Tuna Species

There is not one individual fish called “tuna” – there are more than a dozen species of tuna worldwide.

Many tuna companies, in fact, now track and label their canned tuna products to identify the specific type of tuna, the ocean where it was caught, and more.

Unique Tuna Characteristics

We’re highlighting the major commercial tuna species on this page, six in the genus Thunnus and one in the genus Katsuwonus. “Minor” or less economically important tunas include bullet tuna, blackfin tuna, and tonggol.

Tuna species share some distinctive characteristics.

Due to the physiology of their respiratory system, tunas are obligate ram ventilators — that is, they need to swim constantly to make water pass through their gills.
Because they swim constantly to oxygenate their blood, their muscular metabolism continuously generates heat, which gives them a unique feature among all bony fishes — the ability to regulate their body temperatures. Their thermoregulation capacity enables them to tolerate a wide range of water temperatures.

Tuna are highly migratory. They are widely distributed throughout all oceans in the world between equatorial and subpolar latitudes of both hemispheres. However, some tuna stocks are more abundant — or less heavily fished — than others.

Major Tuna Species

Learn about the characteristics, geographic locations, and more of these major tuna species.


Albacore (Thunnus alalunga)	Bigeye (Thunnus obesus)

Skipjack (Katsuwonus pelamis)	Yellowfin (Thunnus albacares)

Atlantic Bluefin (Thunnus thynnus)	Pacific Bluefin (Thunnus orientalis)

Southern Bluefin (Thunnus maccoyii)

Minor Tuna Species

Among the 15 species of tunas, eight are called “minor” or “neritic” tunas because of their lower commercial value.

But minor tunas still are exploited commercially and/or caught recreationally. Those species are the slender (Allothunnus fallai), frigate (Auxis thazard), bullet (Auxis rochei), black skipjack (Euthynnus lineatus), longtail (Thunnus tonggol), kawakawa (Euthynnus affinis), little tunny (Euthynnus alleteratus) and blackfin (Thunnus atlanticus) tunas.

In an ISSF scientific report on these minor tunas, we review their biology, stock structure, and recent catches. We also identify the main fisheries and fishing gears catching them and evaluate their stock status in different oceans.

Tuna Stock Status

Each year in our “Status of the Stocks” report, we evaluate 23 tuna stocks based on abundance, exploitation/management (fishing mortality), and environmental impact (bycatch).