English: Northern Bluefin Tuna (North-west Pacific + North- East Atlantic + Mediterranean)
Latin: Thunnus thynnus
Size + Weight:  Today's av. catch aboutt 7 kgs 
Biggest Angled Fish:  677 kgs Canada, 1979 Ken Fraser
Catching Areas:  40% North-West Pacific, 19% North-East Atlantic, 6% North-West Atlantic, 35% Mediterranean 
Catching Methods:  Pole and Line, surface trolling and long-line fishing
Share of all Tuna Caught:  About 1,25 % or 40.000 m/t
Main Production Areas: Japan
Life Cycle:  10 to max. 25 years 
Major Markets:  Japan
Popular Product Forms:  Canned (White Tuna) FreshNorthern Bluefin tuna makes extensive migrations. It is the slowest growing tuna species, which can reach an age of 20 years or more, which explains her size. Bluefin is extremely popular in Japan for sashimi, due to its large size, color, texture and high fat content of the meat. It's quality in combination with its rarity make it the most expensive tuna species.
Future Supply: The Northern Bluefin is certainly a tuna species under threat. Its slow growing, in combination with the over-exploitation of the stocks has caused authorities to implement catching quota in the Eastern Atlantic

The Bluefin tuna is an epipelagic and oceanic species; they will come near to the shores seasonally. It can tolerate a considerable wide range of temperatures and has been observed both above and below the thermocline, down to depths greater than 9,850 m.
Bluefin tuna has a strong schooling behavior while they are young. While schooling is believed to be sight orientated, schools have been observed during night time. Therefore, other senses, in particular the lateral line (a sense organ to detect movement and vibration) appears to be involved in this behavior. During the summer months, schools of Bluefin tuna seasonally migrate northwards along the coast of Japan and the Pacific coast of North America. Adult fishes tagged with tracking sensors have made trans-Pacific migrations: some eastward, and some westward. Other tagging studies have shown that a Bluefin can cross the Atlantic Ocean in less than 60 days. They can reach speeds up to 72.5 kilometers per hour.

Distinctive Features:
The Bluefin tuna is one of the largest species of tuna. The body is at its deepest near the insertion of the pelvic fins, and significantly becomes narrower to the caudal peduncle. Compared to other tuna species, the head is long and somewhat pointed, and the eyes are small. There are two dorsal fins present with a small space separating them. The second dorsal fin is taller than the first, and is followed by 7 or up to 10 finlets. The anal fin begins well behind the insertion of the second dorsal fin. The pectoral fins are shorter in comparison to other members of the genus thunnus, although the relative length changes with age. There are three keels present on the caudal peduncle.

Coloration :
The body has a metallic deep blue color above, the lower sides and belly are silvery white. In fresh specimens alternating colorless lines and rows of dots can be seen along the lower sides of a Bluefin tuna. The first dorsal fin has a yellow or blue color; the second is red or brown. The anal fin and finlets are yellow, edged with black. The central caudal keel is black.
Size, Age, and Growth:
The maximum length of Bluefin tuna reported is 458.0 cm in total length and the maximum weight reported is 684 kg. Bluefin tuna will commonly attain a size of 200 cm. The all-tackle record of International Game Fish Association (IGFA) is 679 kg. the Bluefin tuna can have a life span of approximately 15 years.
Bluefin tuna are oviparous. Spawning has been detected in the Atlantic Ocean in only two areas: the Mediterranean and the Gulf of Mexico. Spawning in the Pacific Ocean occurs off the Philippines. In comparison with other tuna species it has a limited spawning area. Spawning in the Gulf of Mexico occurs from April to June and in the Mediterranean spawning occurs from June to August. The variation in timing could be due to differences in environmental cues or genetic variation. In the Mediterranean spawning occurs at seawater temperatures of 19 to 21 °C while in the Gulf of Mexico it occurs at 24.9 to 29.5 °C.
Bluefin tuna under captivity have reached sexual maturity at 3 years; according to others Bluefin become sexually mature at an age 4 to 5 years. Average female Bluefin tuna produce up to 10 million eggs per year. Their eggs are buoyant, and can travel a considerable distance with the help of the surface currents. The larvae have large heads and large jaws, and lack body pigmentation; they hatch at a size of 3.0mm. Bluefin tuna are the only Thunnus species to have dorsal tail pigment, making them easier to be distinguished from other species. In spawning areas, larval abundance can range from 0.1 to 1.0 per square yard. The larvae will grow 1 mm per day and up to a size of 90 to 130 lbs. (40 to 80 kg), and will be separated into schools based upon size. These schools will often consist of multiple species, for example: Albacore, Yellowfin, Bigeye, skipjack, frigate tuna, bonito, and yellowtail.

Stock Status Bluefin Tuna:
Regional Management Organization
State of Stock
Last Edited
Pacific Ocean
Year 2008
Eastern Atlantic Ocean
Year 2007
Mediterranean Sea
year 2007
Western Atlantic Ocean
Year 2007

The popularity of this tuna in commercial markets has led to severe exploitation in several areas, most notably in the North Atlantic Ocean. Currently the Bluefin tuna is listed as data deficient in the redlist of IUCN.


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