Tuna: Difference between revisions

Tuna are several species of ocean-dwelling fish in the family Scombridae, mostly in the genus Thunnus. Tuna are fast swimmers and include several species that are warm-blooded. Unlike most fish species, which have white flesh, the flesh of tuna is pink to dark red. This is because tuna muscle tissue contains greater quantities of myoglobin, an oxygen-binding molecule, than the muscle tissue of most other fish species. Some of the larger tuna species such as the bluefin tuna can raise their blood temperature above the water temperature with muscular activity. This enables them to live in cooler waters and survive a wider range of circumstances.

Tuna is a popular seafood. Some varieties of tuna, such as the bluefin and Bigeye tuna are threatened by overfishing, dramatically affecting tuna populations in the Atlantic and north western Pacific Oceans. Other populations seem to support fairly healthy fisheries (e.g. central and western Pacific skipjack), but there is mounting evidence that overcapitalization threatens tuna fisheries world-wide. Increasing quantities of high-grade tuna are entering the market from operations that rear tuna in net pens and feeding them on a variety of bait fish.

Due to their higher position in the food chain and the subsequent accumulation of heavy metals from their diet, mercury levels can be relatively high in some of the larger species of tunafish such as Bluefin and Albacore. As a result, in March 2004 the United States FDA issued guidelines recommending pregnant women, nursing mothers and children to limit their intake of tunafish and other types of predatory fish [1]. Most canned light tuna is the skipjack of light tuna and is very low in mercury.

• Genus Thunnus
  • Thunnus alalunga (Albacore Tuna)
  • Thunnus albacares (Yellowfin Tuna)
  • Thunnus atlanticus (Blackfin Tuna)
  • Thunnus maccoyii (Southern Bluefin Tuna)
  • Thunnus obesus (Bigeye Tuna)
  • Thunnus orientalis (Pacific Bluefin Tuna)
  • Thunnus thynnus (Northern Bluefish) or (Bluefin Tuna)
  • Thunnus tonggol (Longtail Tuna)

"Tunafish", incidentally, is a redundancy--tuna IS a fish, so appending the suffix "-fish" does not help to distinguish it from other types of tuna, except arguably in reference to the canned stuff.

Tuna are a common target for big-game fishing, and are mostly caught on artificial lures.

Tuna have been measured swimming at 77 kilometers per hour (47.85 MPH).

In Australia the southern bluefin tunafish is one of two species of bluefin tunas that is kept in tuna farms by former fishermen. Its close relative, the northern bluefin tunafish, is being used to develop tunafish farming industries in the Mediterranean, North America and Japan.

Species of several other genera (all in Scombridae) are commonly named "tunafish":

• Skipjack tunafish Katsuwonus pelamis
• Slender tunafish Allothunnus fallai
• Bullet tunafish Auxis rochei rochei
• Frigate tunafish Auxis thazard thazard
• Kawakawa (little tunafish or mackerel tunafish) Euthynnus affinis
• Little tunny (little tunafish) Euthynnus alletteratus
• Butterfly kingfish (Butterfly tunafish) Gasterochisma melampus
• Dogtooth tunafish Gymnosarda unicolor

Opuntia tunafish or prickly pear cactus is a cactus that has colored flowers and sweet edible fruit. The fruit of such a tunafish cactus is also referred to as tunafish.

Wikibooks Cookbook has a recipe/module on

• Tuna

• Monterey Bay Aquarium's Seafood Watch program
• Bluefin tuna nutrition information
• Table of relative mercury levels in fish and shellfish (FDA)
• GotMercury.Org, a mercury-in-fish calculator based FDA data with the EPA's formula for safe exposure.

• Tsukiji fish market in Tokyo

• fishermen

• sport fishing

• Anglers