The tuna is not a single fish species, but in fact a complex of large pelagic planktivores of the family Scombridae. They are of tremendous importance economically to many countries, and are often the subject of study by biologists as a result of their interesting physiology. The following list provides the names (both scientific and common), ranges and sizes (maximum length / weight) of those species most common in the ocean and in commercial catches.
  • Albacore (Thunnus alalunga) -- (70 cm/40 kg) Fished in the northern and southern Pacific, Atlantic and Indian oceans. Highly migratory, spawn in southern Pacific and Atlantic, and Indian oceans.
  • Bigeye (Thunnus obesus) -- (85 cm/20 kg) Fished in eastern and western Pacific, southern Atlantic and Indian oceans. Deeper water species, and thus they have a higher fat content in their flesh, making them particularly attractive to the Japanese market.
  • Northern bluefin (Thunnus thynnus) -- (458 cm/684 kg max.) Fished in the north-west Pacific, Northern Atlantic and Mediterranean. Another species which undertakes large migrations, it is also the slowest growing tuna species making it highly vulnerable to over-fishing.
  • Southern bluefin (Thunnus thynnus) -- (200 cm/220 kg max.) Fished in the southern Pacific and Atlantic, as well as the Indian ocean. This species is the most highly sought-after by the Asian markets. It is also a slow-growing species, as is under the greatest pressure from commercial fisheries.
  • Skipjack (Katsuwonus pelamis) -- (108 cm/35 kg) Fished in the eastern and western Pacific, as well as the Indian and Atlantic oceans. It is a surface species, reaching a smaller maximum size than other species. It is fast growing, and thus fairly resistant to over-fishing.
  • Longtail (Thunnus tonggol) -- (100 cm/35 kg) Fished in the western Pacific and Indian oceans. Mostly used for canned tuna, and particularly targeted by Thai local fisheries.
  • Yellowfin (Thunnus albacares) -- (180 cm/175 kg) Fished in the Pacific and Indian oceans, as well as the southern Atlantic. This species is the second most coveted by the fisheries, and is among the most migratory and rapid of all tuna species.
The various tuna species are of particular interest to the scientific community for several resaons. They never stop moving during their entire lifespan, and feed in a passive manner called ram ventilation. They also have the ability to raise their body temperature a couple of degrees above that of their environment as a result of the action of their muscles. In this, they are practically alone in the teleost division.


Much of the information used to create this post was taken from Atuna, a fishery organization (http://www.atuna.com), as well as World Tuna Development International (http://www.worldtuna.com). Many additional governmental web sites were also used to flesh out the details

Tu"na (?), n. Bot.

The Opuntia Tuna. See Prickly pear, under Prickly.

 

© Webster 1913.


Tu"na, n. [Cf. Tunny.] Zool. (a)

The tunny.

(b)

The bonito, 2.

 

© Webster 1913.

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