Thunnus
| Tuna Temporal range: Middle Eocene to Present[1] |
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| Yellowfin tuna, Thunnus albacares | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Perciformes |
| Family: | Scombridae |
| Tribe: | Thunnini |
| Genus: | Thunnus South, 1845 |
| Species | |
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See text. |
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Thunnus is a genus of ocean-dwelling fish in the family Scombridae, all of which are tuna, although other tuna species are found in other genera. The name of the genus is the Latinized form of the Greek θύννος, thýnnos, tuna, the word being first mentioned in Homer[citation needed]. Due to overfishing the genus range has been significantly reduced, being effectively removed from the Caspian Sea, for example.[2]
Their coloring, metallic blue on top and shimmering silver-white on the bottom, helps camouflage them from above and below.
They can grow to 15 feet long and weigh over 1,000 pounds. They can swim up to 50 miles per hour when pursuing prey.
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[edit] Species
There are eight species:
- Albacore, Thunnus alalunga (Bonnaterre, 1788).
- Bigeye tuna, Thunnus obesus (Lowe, 1839).
- Blackfin tuna, Thunnus atlanticus (Lesson, 1831).
- Pacific bluefin tuna, Thunnus orientalis (Temminck & Schlegel, 1844).
- Atlantic bluefin tuna, Thunnus thynnus (Linnaeus, 1758).
- Southern bluefin tuna, Thunnus maccoyii (Castelnau, 1872).
- Longtail tuna, Thunnus tonggol (Bleeker, 1851).
- Yellowfin tuna, Thunnus albacares (Bonnaterre, 1788).
Atlantic bluefins are warm-blooded, which is a rare trait among fish, and are comfortable in the cold waters. Bluefin fish are found in Newfoundland and Iceland, as well as the tropical waters of the Gulf of Mexico and the Mediterranean Sea, where they go each year to spawn.
Species of several other genera (all in the family Scombridae) also have common names containing tuna.
[edit] Overfishing
The worldwide demand for sushi and sashimi, coupled with increasing population growth, has resulted in global stocks of the species being overfished[3] and bluefin is the most endangered and considered "a serious conservation concern".[4] Complicating the efforts for sustainable management of bluefin fish stocks within national exclusive economic zones (EEZ) is bluefin migrate long distances and hunt in the mid ocean that isn't part of any country's EEZ and therefore have been vulnerable to overfishing by multiple countries' fishing fleets. International agreements and conventions are good faith agreements and are difficult to monitor or enforce.[5] Though this fish has been farmed in captivity by the Japanese and by the Australians with the help of the Japanese,[6] yields are lower than other farmed fish due to the slow growth rate of Bluefin tuna, therefore keeping prices high.[5] In January 2011, a 342 kg bluefin tuna was sold at the Tsukiji fish market in Tokyo for a record 32.49 million Yen (US$396,000).[7]
[edit] References
- ^ Sepkoski, Jack (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology 364: p.560. http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=611&rank=class. Retrieved 2008-01-08.
- ^ *C.Michael Hogan Overfishing. Encyclopedia of Earth. eds. Sidney Draggan and Cutler Cleveland. National council for Science and the Environment, Washington DC
- ^ George Karleskint, Richard Turner, James Small (2009). Introduction to Marine Biology. Cengage Learning. p. 522. ISBN 0495561975. http://books.google.com/books?id=0JkKOFIj5pgC&pg=PA522.
- ^ "Tuna, Bluefin". http://www.montereybayaquarium.org/cr/SeafoodWatch/web/sfw_factsheet.aspx?gid=69.
- ^ a b "Managed to death". The Economist. 2008-10-30. http://www.economist.com/node/12502783?story_id=12502783.
- ^ http://en.wikipedia.org/wiki/Thunnus_orientalis#Farming
- ^ AFP. "Giant Bluefin Tuna Sells for Record Price". Discovery News. http://news.discovery.com/animals/bluefin-tuna-record-auction-110105.html.
[edit] Further reading
- Charles Clover. 2004. The End of the Line: How Overfishing Is Changing the World and What We Eat. Ebury Press, London. ISBN 0-09-189780-7
- Newlands, Nathaniel K.; Molly E. Lutcavage, Tony J. Pitcher (2006). "Atlantic Bluefin Tuna in the Gulf of Maine, I: Estimation of Seasonal Abundance Accounting for Movement, School and School-Aggregation Behaviour". Environmental Biology of Fishes 77 (2): 177–195. doi:10.1007/s10641-006-9069-5. ISSN 0378-1909. http://www.springerlink.com/content/v8417th6pnh7k176/.
[edit] External links
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Wikimedia Commons has media related to: Thunnus |
- Froese, Rainer, and Daniel Pauly, eds. (2006). Species of Thunnus in FishBase. January 2006 version.
- Nutritional benefits of tuna
- The International Commission for the Conservation of Atlantic Tunas
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