![]() "RAD-seq derived genome-wide nuclear markers resolve the phylogeny of tunas". ![]() ^ a b c Díaz-Arce, Natalia Arrizabalaga, Haritz Murua, Hilario Irigoien, Xabier Rodríguez-Ezpelata, Naiara (2016)."ROrthodox and unorthodox phylogenetic relationships among tunas revealed by the nucleotide sequence analysis of the mitochondrial DNA control region". In the Perseus Digital Library, Tufts University. ^ θύννος in Liddell, Henry George Scott, Robert (1940) A Greek–English Lexicon, revised and augmented throughout by Jones, Sir Henry Stuart, with the assistance of McKenzie, Roderick.National council for Science and the Environment, Washington DC "Sharing the water column: physiological mechanisms underlying species-specific habitat use in tunas". "A compendium of fossil marine animal genera". On December 30, 2012, a 222-kilogram (489 lb) bluefin tuna caught off northeastern Japan, was sold at the Tsukiji fish market in Tokyo for a record 155.4 million yen ($1.76 million) – a unit price of JP¥ 1.274 million/kg (US$3,600/lb). Though this fish has been farmed in captivity by the Japanese and by the Australians with the help of the Japanese, yields are lower than other farmed fish due to the slow growth rate of bluefin tuna, therefore keeping prices high. International agreements and conventions are good-faith agreements and are difficult to monitor or enforce. 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 midocean that is not part of any country's EEZ, so have been vulnerable to overfishing by multiple countries' fishing fleets. The worldwide demand for sushi and sashimi, coupled with increasing population growth, has resulted in global stocks of the species being overfished and bluefin is the most endangered and considered "a serious conservation concern". Thunnus ( Neothunnus) – the yellowfin group In 1999, Collette established that based on both molecular and morphological considerations, they are, in fact, distinct species. Until recently, seven Thunnus species were thought to exist, and Atlantic bluefin tuna and Pacific bluefin tuna were subspecies of a single species. Earlier nuclear ribosomal DNA phylogenetic reconstructions also showed similar results. Specifically, these analyses substantiated the division of Pacific and Atlantic Tuna in two separate species and suggested that Bigeye Tuna were actually a member of subgenus Neothunnus, not subgenus Thunnus. However this classification has been questioned by a recent phylogenetic analysis of nuclear DNA sequence data, which resolved different relationships among species and did not support the traditional definition of the bluefin and yellowfin groups. īased on morphology and short-length mitochondrial DNA sequence data, the genus Thunnus is currently classified into two subgenera: Thunnus (Thunnus) (the bluefin group), and Thunnus (Neothunnus) (the yellowfin group). The first written use of the word was by Homer. The word Thunnus is the Middle Latin form of the Greek thýnnos ( θύννος, "tuna, tunny") – which is in turn derived from thynō ( θύνω, "to rush to dart"). Bluefin tunas, for example, are found in Newfoundland and Iceland, and also in the tropical waters of the Gulf of Mexico and the Mediterranean Sea, where some individuals go each year to spawn.ĭue to overfishing, the range of this genus has declined significantly, having been effectively extirpated from the Black Sea, for example. As with all tunas, members of this genus are warm-blooded, which is a rare trait among fish this enables them to tolerate cold waters and to dive to deeper depths. All tunas are extremely strong swimmers, and the yellowfin tuna is known to reach speeds of up to 50 miles per hour (80 km/h) when pursuing prey. Atlantic bluefin tuna, the largest member of this genus, can grow to 15 feet (4.6 m) long and weigh up to 1,500 pounds (680 kg). Their coloring, metallic blue on top and shimmering silver-white on the bottom, helps camouflage them from above and below. Also called the true tunas or real tunas, Thunnus consists of eight species of tuna (more than half of the overall tribe), divided into two subgenera. More specifically, Thunnus is one of five genera which make up the tribe Thunnini – a tribe that is collectively known as the tunas. Thunnus is a genus of ocean-dwelling, ray-finned bony fish from the mackerel family, Scombridae.
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