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.

We’re highlighting the seven major commercial tuna species on this page, six in the genus Thunnus and one in the genus Katsuwonus. “Minor” or less economically important tunas, not covered here, include bullet tuna, blackfin tuna, and tonggol.

Tuna species share some distinctive characteristics. For instance, 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.

Consequently, 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. To learn about the status and sustainability considerations for each tuna species below, read our Status of the Stocks report.

Albacore (Thunnus alalunga)

Albacore (Thunnus alalunga), one of the smaller major tuna species, is a temperate species widely distributed in temperate and tropical waters of all oceans. Albacore tend to travel in single species schools, without the level of mixing seen in other species. Association with floating objects is not common.

 

SPECIES CHARACTERISTICS

  Size (cm) Weight (kg) Age (yrs)
Common 40-100    
Maximum 130    
Maturity 75-90 8-15 2-5

GEOGRAPHIC LIMITS

  • Generally limited to temperate and tropical waters
  • From 45-50° N and 30-40° S in the Atlantic Ocean
  • From 5° N to 40° S in the Indian Ocean, with adults occurring from 5° N to 25° S

SPECIES MANAGEMENT

The following six albacore stocks are assessed and managed by the RFMOs:

  • North Pacific Ocean
  • South Pacific Ocean
  • North Atlantic Ocean
  • South Atlantic Ocean
  • Mediterranean Sea
  • Indian Ocean
See Albacore-related News

Skipjack (Katsuwonus pelamis)

Skipjack (Katsuwonus pelamis), the smallest of the commercial tuna species, form both free schools and schools associated with floating objects. Found mainly in the tropical areas of the Atlantic, Indian and Pacific Oceans, skipjack are the principal species associated with FADs and are caught in conjunction with juvenile yellowfin and bigeye tunas.

 

SPECIES CHARACTERISTICS

  Size (cm) Weight (kg) Age (yrs)
Common 40-80    
Maximum 108 33 6-10
Maturity 43 1.6 1-1.5

GEOGRAPHIC LIMITS

  • 55-60° N and 45-50° S
  • The greatest abundance is seen in equatorial waters

SPECIES MANAGEMENT

The following five skipjack stocks are assessed and managed by the RFMOs:

  • Eastern Atlantic
  • Western Atlantic
  • Eastern Pacific
  • Western Pacific
  • Indian Ocean
See Skipjack-related News

Atlantic Bluefin (Thunnus thynnus)

Atlantic bluefin (Thunnus thynnus) is one of three bluefin tuna species, together with Pacific bluefin and Southern bluefin.

For many years, bluefin tunas around the Northern Hemisphere were considered to be the same, or one subspecies. They were only recently divided as a result of the scientific agreement that Atlantic bluefin and Pacific bluefin (Thunnus orientalis) are separate species.

The Atlantic bluefin is the largest of the tuna species. It can reach 3 meters in length (or nearly 10 feet), although the common size ranges between 80 and 200 cm. 

The Atlantic bluefin tolerates a wide range of temperatures. It lives in subtropical and temperate waters of the Atlantic Ocean and the Mediterranean and Black seas, although sightings in the Black Sea are now rare. They are highly migratory and tend to form schools by size. Sometimes bluefin can be seen together with other tuna species like albacore, yellowfin, bigeye, and skipjack.

 

SPECIES CHARACTERISTICS

  Size (cm) Weight (kg) Age (yrs)
Common 80-200 145-300 25+
Maximum 458 679 35
Maturity 110-190 30-120 4-14

GEOGRAPHIC LIMITS

  • In the eastern Atlantic, this species is present from Norway to the Canary Islands, including the Mediterranean and the southern part of the Black Sea, between 80-70°N and 20-10°N.
  • In the western Atlantic, Thunnus thynnus ranges from Canada to Brazil, including the Gulf of Mexico and the Caribbean Sea, between 60-50°N and the Equator.
  • 80°N to 60°S, 100°W to 20°E

SPECIES MANAGEMENT

The following Atlantic bluefin stocks are managed by the International Commission for the Conservation of Atlantic Tunas (ICCAT) RFMO:

  • Eastern Atlantic and Mediterranean bluefin
  • Western Atlantic bluefin
See Atlantic-Bluefin-related News

Southern Bluefin (Thunnus maccoyii)

Southern bluefin tuna (Thunnus maccoyii) was the first of the three bluefin tunas to be recognized as a distinct species. Like the other bluefin tunas (T. thynnus and T. orientalis), Southern bluefin reaches large sizes: adults commonly grow to 180 cm in length.

Thunnus maccoyii is found in the Southern Hemisphere in the temperate and cold waters of the Atlantic, Indian and Pacific oceans. Southern bluefin’s thermoregulation capacity enables it to tolerate water temperatures from more than 25°C in the subtropics to less than 3°C in the sub-Antarctic regions. Southern bluefins migrate vast distances and tend to form schools by size, especially when they are juveniles and during the spawning season.

 

SPECIES CHARACTERISTICS

  Size (cm) Weight (kg) Age (yrs)
Common 160 180 14+
Maximum 245 260 40
Maturity 120-150 100-160 8-12

GEOGRAPHIC LIMITS

  • Thunnus maccoyii is found in the Southern Hemisphere of the Atlantic, Indian and Pacific Oceans.
  • Its geographical range varies between 30°S and 50°S, to nearly 60°S.

SPECIES MANAGEMENT

See Southern-Bluefin-related News

Bigeye (Thunnus obesus)

Bigeye (Thunnus obesus) are found in the tropical and subtropical areas of the Atlantic (but not in the Mediterranean), Indian, and Pacific Oceans. Bigeye reach similar maximum sizes as yellowfin tuna. Bigeye can form either free-swimming schools or schools associated with floating objects. Juvenile bigeye will form schools with juvenile yellowfin and skipjack tunas. 

 

SPECIES CHARACTERISTICS

  Size (cm) Weight (kg) Age (yrs)
Common 40-180 1.4-130  
Maximum 230 210 15
Maturity 102-135 25-57 3-4

GEOGRAPHIC LIMITS

  • From 55-60° N and 45-50° S
  • Juvenile and reproductively active adult bigeye are found in equatorial waters as well as at higher latitudes. 

SPECIES MANAGEMENT

The following four bigeye stocks are assessed and managed by the RFMOs:

  • Atlantic Ocean
  • Eastern Pacific
  • Western Pacific
  • Indian Ocean
See Bigeye-related News

Yellowfin (Thunnus albacares)

Yellowfin (Thunnus albacares) are found in the tropical and subtropical areas of the Atlantic, Indian, and Pacific Oceans. Yellowfin reach intermediate sizes, between albacore and bigeye. They form both free and associated schools, with adults generally forming schools of similarly sized individuals. The free-swimming schools tend to contain large individuals and are mono-specific. In the Eastern Pacific, schools are often associated with dolphin pods, which is not common elsewhere.

 

SPECIES CHARACTERISTICS

  Size (cm) Weight (kg) Age (yrs)
Common 40-170 1.2-100  
Maximum 205 194 8
Maturity 85-108 12-26 2-3

GEOGRAPHIC LIMITS

  • From 45°-50° N and S, although in the Pacific Ocean they occur mainly from 20° North and South

SPECIES MANAGEMENT

The following four yellowfin stocks are assessed and managed by the RFMOs:

  • Atlantic Ocean
  • Eastern Pacific
  • Western Pacific
  • Indian Ocean
See Yellowfin-related News

Pacific Bluefin (Thunnus orientalis)

Pacific bluefin (Thunnus orientalis) is one of three bluefin species, together with Atlantic bluefin and Southern bluefin. Atlantic bluefin and Pacific bluefin only recently came to be viewed by marine scientists as separate species.

Although it is generally smaller than Atlantic bluefin, Pacific bluefin is also one of the largest of the tuna species, ranging between 80–200 cm in length. It has the largest geographic range of all tunas, widely distributed throughout the North Pacific Ocean — from East Asia to the North American West Coast — and with a more limited presence in the Southern Hemisphere.

Thunnus orientalis is a temperate tuna species that can also range into tropical waters. It is considered to consist of only one stock and it forms schools by size, sometimes with other tuna and mackerel species.

SPECIES CHARACTERISTICS

  Size (cm) Weight (kg) Age (yrs)
Common 120-210 100-260 15+
Maximum 300 540 20
Maturity 100-150 50-60 3-5

GEOGRAPHIC LIMITS

  • Pacific bluefin distribution is from the Gulf of Alaska to Baja California in the east (between 60°N and 20°N) and from Sakhalin Island to New Zealand in the west (between 50°N and 50°S).
  • There are also records of this species around the islands of French Polynesia.
  • 60°N to 50°S, 140°E to 90°W

SPECIES MANAGEMENT

Given Pacific bluefin’s wide geographic range, the species is managed by two different Regional Fisheries Management Organizations:

  • The Western and Central Pacific Fisheries Commission (WCPFC)
  • The Inter-American Tropical Tuna Commission (IATTC)
See Pacific-Bluefin-related News