|Genus:|| Thunnus |
Thunnus is a genus of ocean-dwelling, ray-finned bony fish from the mackerel family, Scombridae. More specifically, Thunnus is one of five genera which make up the tribe Thunnini – a tribe that is collectively known as the tunas. 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. 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"). The first written use of the word was by Homer.[ citation needed ]
Their coloring, metallic blue on top and shimmering silver-white on the bottom, helps camouflage them from above and below. 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). 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. 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. 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.
Due to overfishing, the range of this genus has declined significantly, having been effectively extirpated from the Black Sea, for example.
Based 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). 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. 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. Earlier nuclear ribosomal DNA phylogenetic reconstructions also showed similar results.
This genus has eight species in two subgenera:
|Alternative evolutionary tree for Thunnus|
|An alternative phylogenetic reconstruction for the genus Thunnus, based on nuclear DNA sequence data, which modifies the traditionally recognized bluefin and yellowfin clades by placing Thunnus obesus within the yellowfin clade instead of in the bluefin clade.|
Until recently, seven Thunnus species were thought to exist, and Atlantic bluefin tuna and Pacific bluefin tuna were subspecies of a single species. In 1999, Collette established that based on both molecular and morphological considerations, they are, in fact, distinct species.
|Thunnus, the true tunas|
|Image||Common name||Scientific name||Maximum|
|Thunnus (Thunnus) – the bluefin group|
|Albacore tuna||T. alalunga|
|1.4 m |
|1.0 m |
|60.3 kg |
|9–13 yrs||4.31||Least Concern|
|Southern bluefin tuna||T. maccoyii|
|2.45 m |
|1.6 m |
|260 kg |
|Bigeye tuna||T. obesus|
|2.5 m |
|1.8 m |
|210 kg |
|Pacific bluefin tuna||T. orientalis|
(Temminck & Schlegel, 1844)
|3.0 m |
|2.0 m |
|450 kg |
|15–26 yrs||4.21||Near Threatened|
|Atlantic bluefin tuna||T. thynnus|
|4.6 m |
|2.0 m |
|684 kg |
|35–50 yrs||4.43||Least Concern|
|Thunnus (Neothunnus) – the yellowfin group|
|Blackfin tuna||T. atlanticus|
|1.1 m |
|0.7 m |
|22.4 kg |
| Longtail tuna, |
northern bluefin tuna,
|1.45 m |
|0.7 m |
|35.9 kg |
|18 years||4.50||Data deficient|
|Yellowfin tuna||T. albacares|
|2.4 m |
|1.5 m |
|200 kg |
|5–9 yrs||4.34||Least Concern|
The worldwide demand for sushi and sashimi, coupled with increasing population growth, has resulted in global stocks of the species being overfished 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).and bluefin is the most endangered and considered "a serious conservation concern". 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. International agreements and conventions are good-faith agreements and are difficult to monitor or enforce. 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. On December 30, 2012, a
A tuna is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae (mackerel) family. The Thunnini comprise 15 species across five genera, the sizes of which vary greatly, ranging from the bullet tuna up to the Atlantic bluefin tuna, which averages 2 m (6.6 ft) and is believed to live up to 50 years.
Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment.
The mackerel, tuna, and bonito family, Scombridae, includes many of the most important and familiar food fishes. The family consists of 51 species in 15 genera and two subfamilies. All species are in the subfamily Scombrinae, except the butterfly kingfish, which is the sole member of subfamily Gasterochismatinae.
The albacore, known also as the longfin tuna, is a species of tuna of the order Perciformes. It is found in temperate and tropical waters across the globe in the epipelagic and mesopelagic zones. There are six distinct stocks known globally in the Atlantic, Pacific, and Indian oceans, as well as the Mediterranean Sea. The albacore has an elongate, fusiform body with a conical snout, large eyes, and remarkably long pectoral fins. Its body is a deep blue dorsally and shades of silvery white ventrally. Individuals can reach up to 1.4 m in length.
The Atlantic bluefin tuna is a species of tuna in the family Scombridae. It is variously known as the northern bluefin tuna, giant bluefin tuna [for individuals exceeding 150 kg (330 lb)], and formerly as the tunny.
The yellowfin tuna is a species of tuna found in pelagic waters of tropical and subtropical oceans worldwide.
The International Commission for the Conservation of Atlantic Tunas (ICCAT) is a tuna regional fishery management organisation, responsible for the management and conservation of tuna and tuna-like species in the Atlantic Ocean and adjacent seas. The organization was established in 1966, at a conference in Rio de Janeiro, Brazil, and operates in English, French and Spanish. The organisation has been strongly criticised by scientists for its repeated failure to conserve the sustainability of the tuna fishery by consistently supporting over-fishing – an internal review branded ICCAT's policies on the eastern Atlantic bluefin tuna fishery a "travesty of fisheries management", and an "international disgrace". Conservationists often refer to ICCAT as "The International Conspiracy to Catch All Tuna".
The term billfish refers to a group of saltwater predatory fish characterised by prominent pointed bills (rostra), and by their large size; some are longer than 4 m (13 ft). Extant billfish include sailfish and marlin, which make up the family Istiophoridae; and swordfish, sole member of the family Xiphiidae. They are apex predators which feed on a wide variety of smaller fish, crustaceans and cephalopods. These two families are sometimes classified as belonging to the order Istiophoriformes, a group which originated around 71 million years ago in the Late Cretaceous, with the two families diverging around 15 million years ago in the Late Miocene. However, they are also classified as being closely related to the mackerels and tuna within the suborder Scombroidei of the order Perciformes. However, the 5th edition of the Fishes of the World does recognise the Istiophoriformes as a valid order, albeit including the Sphyraenidae, the barracudas.
Pelagic fish live in the pelagic zone of ocean or lake waters—being neither close to the bottom nor near the shore—in contrast with demersal fish that do live on or near the bottom, and reef fish that are associated with coral reefs.
The bigeye tuna is a species of true tuna of the genus Thunnus, belonging to the wider mackerel family Scombridae. In Hawaiian, it is one of two species known as ʻahi, the other being the yellowfin tuna. Bigeye tuna are found in the open waters of all tropical and temperate oceans, but not in the Mediterranean Sea.
Fistularia tabacaria, the cornetfish, blue-spotted cornetfish, tobacco trumpetfish or unarmed trumpetfish, is a species of cornetfish found along the Atlantic coasts of the Americas and in the central Atlantic off West Africa and the Macaronesian Islands. This species is of minor importance in commercial fisheries.
The southern bluefin tuna is a tuna of the family Scombridae found in open southern Hemisphere waters of all the world's oceans mainly between 30°S and 50°S, to nearly 60°S. At up to 2.5 metres and weighing up to 260 kilograms (570 lb), it is among the larger bony fishes.
The blackfin tuna is a species of tuna in the family Scombridae. It is occasionally referred to as the bermuda tuna, blackfinned albacore, or deep bodied tunny. They are the smallest tuna species in the genus Thunnus, generally growing to a maximum of 100 cm (39 in) in length and weighing 21 kg (46 lb).
The Pacific bluefin tuna is a predatory species of tuna found widely in the northern Pacific Ocean, but it is migratory and also recorded as a visitor to the south Pacific.
Euthynnus is a genus of ray-finned bony fish in the family Scombridae, or mackerel family, and in the tribe Thunnini, more commonly known as the tunas.
Thunnus tonggol is a species of tuna of tropical Indo-West Pacific waters.
Several fish species are known as northern bluefin tuna including:
Thunnus (Neothunnus) is a subgenus of ray-finned bony fishes in the Thunnini, or tuna, tribe. More specifically, Neothunnus is a subgenus of the genus Thunnus, also known as the "true tunas". Neothunnus is sometimes referred to as the yellowfin group, and comprises three species:
Thunnus (Thunnus) is a subgenus of ray-finned bony fishes in the Thunnini, or tuna, tribe. More specifically, Thunnus (Thunnus) is a subgenus of the genus Thunnus, also known as the "true tunas". Thunnus (Thunnus) is sometimes referred to as the bluefin group and comprises five species:
Brama dussumieri, the lesser bream or lowfin pomfret, is a species of marine ray-finned fish, a pomfret of the family Bramidae. It is found in warm seas around the world.