121-528: The albacore ( Thunnus alalunga ), known also as the longfin tuna , is a species of tuna of the order Scombriformes . 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
242-661: A calque (loan translation) from the German Thunfisch . Canned tuna is sometimes used as food for pets, especially cats . Canned tuna was first produced in Australia in 1903 and quickly became popular. In the early 1980s canned tuna in Australia was most likely southern bluefin , as of 2003 it was usually yellowfin, skipjack , or tongol (labelled "northern bluefin" or "longtail"). Australian standards once required cans of tuna to contain at least 51% tuna, but those regulations were dropped in 2003. The remaining weight
363-471: A food fish , and is popular as a bluewater game fish . As a result of overfishing , some tuna species, such as the southern bluefin tuna , are threatened with extinction . The term "tuna" comes from Spanish atún < Andalusian Arabic at-tūn , assimilated from al-tūn التون [Modern Arabic التن ] : 'tuna fish' < Middle Latin thunnus . Thunnus is derived from Ancient Greek : θύννος , romanized : thýnnos used for
484-654: A "best choice" for consumers, although notes some "moderate concerns" regarding the management effectiveness (in particular, no definitive assessment of the albacore stock of the Indian Ocean fishery has taken place), and "moderate concern" over the fishing stock, especially regarding the North Atlantic albacore population, which the National Marine Fisheries Service (NMFS) considers overfished with overfishing still occurring. In 2007, SeaChoice considered
605-580: A 1:1 sex ratio while older albacore are mostly male. In the Atlantic Ocean, older fish are found in cooler waters. The opposite is true for the Pacific Ocean, where fish are found more abundantly along thermal discontinuities. Depth range also varies by location: Atlantic fish dive as deep as 600 m (2,000 ft) where Pacific fish reach only 380 m (1,250 ft) in depth. In the northeast Atlantic, feeding migrations to productive areas occur during
726-414: 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 (4 ft 7 in) in length. Albacore are pelagic predators that eat a wide variety of foods, including but not limited to fish , crustaceans , and cephalopods . They are unique among tuna in that their primary food source
847-430: A different reason. Unlike dolphins, these fish do not feel the bubbles, because they have bony fins without nerve endings. Nevertheless, they cannot swim faster because the cavitation bubbles create a vapor film around their fins that limits their speed. Lesions have been found on tuna that are consistent with cavitation damage. Scombrid fishes (tuna, mackerel and bonito) are particularly high-performance swimmers. Along
968-664: A different record was set when a fisherman in Massachusetts caught an 881 lb (400 kg) tuna. It was captured inadvertently using a dragnet. Due to the laws and restrictions on tuna fishing in the United States, federal authorities impounded the fish because it was not caught with a rod and reel. Because of the tuna's deteriorated condition as a result of the trawl net, the fish sold for just under $ 5,000. Besides for edible purposes, many tuna species are caught frequently as game, often for recreation or for contests in which money
1089-442: A homocercal tail. These come in a variety of shapes, and can appear: (D) - Diphycercal means the vertebrae extend to the tip of the tail and the tail is symmetrical and expanded (as in the bichir , lungfish , lamprey , coelacanths and † Tarrasiiformes ). Most Palaeozoic fishes had a diphycercal heterocercal tail. Finlets are small fins, generally behind the dorsal and anal fins (in bichirs , there are only finlets on
1210-462: A lifespan of 11–12 years, but they reach reproductive maturity at around 5–6 years. A large majority of albacore have larger right testes or ovaries, depending on sex. Albacore have asynchronous oocyte development, that is their immature egg cells do not develop at regular intervals. The creation of ova , known as oogenesis , begins with the rapid production of oogonia (undifferentiated germ cells that give rise to oocytes) by mitotic separations in
1331-515: A liquid, which then promptly and violently collapse. It can cause significant damage and wear. Cavitation damage can occur to the tail fins of powerful swimming marine animals, such as dolphins and tuna. Cavitation is more likely to occur near the surface of the ocean, where the ambient water pressure is relatively low. Even if they have the power to swim faster, dolphins may have to restrict their speed because collapsing cavitation bubbles on their tail are too painful. Cavitation also slows tuna, but for
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#17328547767751452-508: A modified fin to deliver sperm; thresher sharks use their caudal fin to whip and stun prey; reef stonefish have spines in their dorsal fins that inject venom as an anti-predator defense ; anglerfish use the first spine of their dorsal fin like a fishing rod to lure prey; and triggerfish avoid predators by squeezing into coral crevices and using spines in their fins to anchor themselves in place. Fins can either be paired or unpaired . The pectoral and pelvic fins are paired, whereas
1573-439: A more disproportionate way than other fins on female fish." There are two prevailing hypotheses that have been historically debated as models for the evolution of paired fins in fish: the gill arch theory and the lateral fin-fold theory. The former, commonly referred to as the " Gegenbaur hypothesis ," was posited in 1870 and proposes that the "paired fins are derived from gill structures". This fell out of popularity in favor of
1694-416: A neural network in the fin, indicating that it likely has a sensory function, but are still not sure exactly what the consequences of removing it are. A comparative study in 2013 indicates the adipose fin can develop in two different ways. One is the salmoniform-type way, where the adipose fin develops from the larval-fin fold at the same time and in the same direct manner as the other median fins. The other
1815-705: A pancake, and will fit into fissures in rocks. Their pelvic and pectoral fins have evolved differently, so they act together with the flattened body to optimise manoeuvrability. Some fishes, such as puffer fish , filefish and trunkfish , rely on pectoral fins for swimming and hardly use tail fins at all. Male cartilaginous fishes (sharks and rays), as well as the males of some live-bearing ray finned fishes , have fins that have been modified to function as intromittent organs , reproductive appendages which allow internal fertilization . In ray finned fish, they are called gonopodia or andropodia , and in cartilaginous fish, they are called claspers . Gonopodia are found on
1936-549: A prominent dorsal fin. Like scombroids and other billfish , they streamline themselves by retracting their dorsal fins into a groove in their body when they swim. The huge dorsal fin, or sail, of the sailfish is kept retracted most of the time. Sailfish raise them if they want to herd a school of small fish, and also after periods of high activity, presumably to cool down. The oriental flying gurnard has large pectoral fins which it normally holds against its body, and expands when threatened to scare predators. Despite its name, it
2057-465: A relatively narrow range. Tunas achieve endothermy by conserving the heat generated through normal metabolism . In all tunas, the heart operates at ambient temperature , as it receives cooled blood, and coronary circulation is directly from the gills . The rete mirabile ("wonderful net"), the intertwining of veins and arteries in the body's periphery, allows nearly all of the metabolic heat from venous blood to be "re-claimed" and transferred to
2178-485: A single fish – the current record is 333.6 million japanese yen (US$ 3.1 million) for a 278 kg (613 lb) bluefin, or a unit price of JP¥ 1,200,000/kg (US$ 5,057/lb). The opening auction price for 2014 plummeted to less than 5% of the previous year's price, which had drawn complaints for climbing "way out of line". A summary of record-setting auctions are shown in the following table (highlighted values indicate new world records): In November 2011,
2299-405: A streamlined, fusiform body with a conical snout, large mouth, and big eyes. Its body is dark blue dorsally, shades of silvery white ventrally, and covered by small scales. The pectoral fins begin slightly before the first dorsal fin and extend well beyond the front of the anal fin , usually as far as the second dorsal finlet, often as long as 30% of the fish's total length. Like the fish's body,
2420-454: A thin stretch of scaleless skin ; in lobe-finned fish ( Sarcopterygii ) such as coelacanths and lungfish , fins are short rays based around a muscular central bud supported by jointed bones ; in cartilaginous fish ( Chondrichthyes ) and jawless fish ( Agnatha ), fins are fleshy " flippers " supported by a cartilaginous skeleton. Fins at different locations of the fish body serve different purposes, and are divided into two groups:
2541-460: A variety of other gears the remainder. The Australian government alleged in 2006 that Japan had illegally overfished southern bluefin by taking 12,000 to 20,000 tonnes per year instead of the agreed upon 6,000 tonnes; the value of such overfishing would be as much as US$ 2 billion. Such overfishing has severely damaged bluefin stocks. According to the WWF , "Japan's huge appetite for tuna will take
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#17328547767752662-673: A western Pacific-wide ban on tuna purse-seining in the vicinity of marine mammals – a measure which was agreed by the Western and Central Pacific Fisheries Commission at its eighth meeting in March 2012. Dolphins swim beside several tuna species. These include yellowfin tuna in the eastern Pacific Ocean, but not albacore . Tuna schools are believed to associate themselves with dolphins for protection against sharks, which are tuna predators . Commercial fishing vessels used to exploit this association by searching for dolphin pods. Vessels would encircle
2783-487: A woman from before she becomes pregnant. Ranging from as low as 0.027 ppm (parts per million) to 0.26 ppm, the average total mercury content of albacore is 0.14 ± 0.05 ppm. Larger fish tend to bioaccumulate higher methylmercury levels. For the most part, there is positive correlation between an albacore's methylmercury measurement and its weight and length. Albacore caught by the American albacore fishing fleet off
2904-650: Is Heteroteuthis dispar , a tiny deep-water squid found in the Mediterranean Sea and Atlantic Ocean. Another cephalopod species preyed upon is Berryteuthis anonychus . Other food sources of the albacore include fish (including Cololabis saira , Engraulis japonicus , and Engraulis mordax ), crustaceans, and gelatinous organisms. Not much is known about the food pattern of the albacore, however, mostly because it dives over 400 m (1,300 ft) underwater when searching for food, and tagging and tracking has been unsuccessful thus far. The albacore's reproduction
3025-420: Is oviparous and a 20 kg (44 lb) female can produce between 2–3 million eggs per spawning, which usually takes place between November and February. Eggs mature outside of the female's body and hatch in 1–2 days, after which fry begin to grow quickly. For the first year of their lives, juveniles remain close to the place where they were hatched. They begin to migrate after their first year. Albacore have
3146-413: Is a demersal fish , not a flying fish, and uses its pelvic fins to walk along the bottom of the ocean. Fins can have an adaptive significance as sexual ornaments. During courtship, the female cichlid , Pelvicachromis taeniatus , displays a large and visually arresting purple pelvic fin . "The researchers found that males clearly preferred females with a larger pelvic fin and that pelvic fins grew in
3267-455: Is a sleek, elongated and streamlined fish, adapted for speed. It has two closely spaced but separated dorsal fins on its back; The first fin is "depressible" – it can be laid down, flush, in a groove that runs along its back; it is supported by spines. Seven to ten yellow finlets run from the dorsal fins to the tail, which is lunate – curved like a crescent moon – and tapered to pointy tips. A tuna's pelvic fins are located below
3388-409: Is a tool for visualizing and comparing the evolutionary relationships between taxa , and is read left-to-right as if on a timeline. The following cladogram illustrates the relationship between the tunas and other tribes of the family Scombridae. For example, the cladogram illustrates that the skipjack tunas are more closely related to the true tunas than are the slender tunas (the most primitive of
3509-458: Is a versatile ingredient that is used a wide variety of dishes. In some parts of the world, other species may be called "albacore": Tuna A tuna ( pl. : tunas or tuna) is a saltwater fish that belongs to the tribe Thunnini , a subgrouping of the Scombridae ( mackerel ) family. The Thunnini comprise 17 species across five genera , the sizes of which vary greatly, ranging from
3630-565: Is an important commercial fish . The International Seafood Sustainability Foundation (ISSF) compiled a detailed scientific report on the state of global tuna stocks in 2009, which includes regular updates. According to the ISSF, the most important species for commercial and recreational tuna fisheries are yellowfin ( Thunnus albacares ), bigeye ( T. obesus ), bluefin ( T. thynnus , T. orientalis , and T. macoyii ), albacore ( T. alalunga ), and skipjack ( Katsuwonus pelamis ). Based on catches from 2007,
3751-803: Is awarded based on weight. Larger specimens are notorious for putting up a fight while hooked, and have been known to injure people who try to catch them, as well as damage their equipment. In 2005, Nauru , defending its vote from Australian criticism at that year's meeting of the International Whaling Commission , argued that some whale species have the potential to devastate Nauru's tuna stocks, and that Nauru's food security and economy relies heavily on fishing. Despite this, Nauru does not permit whaling in its own waters and does not allow other fishing vessels to take or intentionally interact with marine mammals in its Exclusive Economic Zone. In 2010 and 2011, Nauru supported Australian proposals for
Albacore - Misplaced Pages Continue
3872-415: Is cephalopods, with fish making up a much smaller portion of their diet. Reproduction usually occurs from November to February and is oviparous . An adult female can release over two million eggs in a single cycle. Fry (juvenile fish) generally stay near where they were spawned for about a year before moving on. Albacore form schools based on their stage in the life cycle, but also combine with other tuna like
3993-415: Is likely to result in further declines in albacore biomass. All of the tuna Regional Fisheries Management Organizations noted that there is uncertainty surrounding the life history and biology of tunas and tuna like species including age and growth, maturity, and natural mortality rates; uncertainty about the quality and completeness of available data; and uncertainty about recruitment. The WCPFC has assessed
4114-614: Is one type of living lobe-finned fish. Both extant members of this group, the West Indian Ocean coelacanth ( Latimeria chalumnae ) and the Indonesian coelacanth ( Latimeria menadoensis ), are found in the genus Latimeria . Coelacanths are thought to have evolved roughly into their current form about 408 million years ago, during the early Devonian. Locomotion of the coelacanths is unique to their kind. To move around, coelacanths most commonly take advantage of up or downwellings of
4235-441: Is only slightly larger at 1.0 m (3 ft 3 in). Males and females exhibit no sexual dimorphism . The albacore has a cosmopolitan distribution in tropical and temperate waters across the globe and in every ocean as well as the Mediterranean Sea. Its latitudinal range extends from 59°N to 46°S . Its temperature range is 10–25 °C (50–77 °F). Its depth range is 0–600 m (0–1,969 ft; 0–328 fathoms) in
4356-436: Is prohibited in many countries. Foil shaped fins generate thrust when moved, the lift of the fin sets water or air in motion and pushes the fin in the opposite direction. Aquatic animals get significant thrust by moving fins back and forth in water. Often the tail fin is used, but some aquatic animals generate thrust from pectoral fins . Cavitation occurs when negative pressure causes bubbles (cavities) to form in
4477-432: Is relatively conservative in lobe-finned fishes. However, there are a few examples from the fossil record that show aberrant morphologies , such as Allenypterus , Rebellatrix , Foreyia or the tetrapodomorphs . Ray-finned fishes form a class of bony fishes called Actinopterygii. Their fins contain spines or rays. A fin may contain only spiny rays, only soft rays, or a combination of both. If both are present,
4598-659: Is shipped, being prepared in a variety of ways. When served as a steak , the meat of most species is known for its thickness and tough texture. In the U.K., supermarkets began flying in fresh tuna steaks in the late 1990s, which helped to increase the popularity of using fresh tuna in cooking; by 2009, celebrity chefs regularly featured fresh tuna in salads, wraps, and char-grilled dishes. Various species of tuna are often served raw in Japanese cuisine as sushi or sashimi . Commercial sashimi tuna may have their coloration fixated by pumping carbon monoxide (CO) into bags containing
4719-444: Is smaller than the first, is a light yellow, as is the anal fin. It has 7–9 dorsal finlets and 7–8 anal finlets, dark blue and silvery white in color respectively, matching the part of the fish's body they are on. The caudal fin is also silvery white. At 1.4 m (4 ft 7 in) maximum length, the albacore is the smallest of the bluefin tuna . It reaches sexual maturity at 0.9 m (2 ft 11 in) and its common length
4840-402: Is something of a mystery. It is frequently clipped off to mark hatchery-raised fish, though data from 2005 showed that trout with their adipose fin removed have an 8% higher tailbeat frequency. Additional information released in 2011 has suggested that the fin may be vital for the detection of, and response to, stimuli such as touch, sound and changes in pressure. Canadian researchers identified
4961-487: Is the characiform-type way, where the adipose fin develops late after the larval-fin fold has diminished and the other median fins have developed. They claim the existence of the characiform-type of development suggests the adipose fin is not "just a larval fin fold remainder" and is inconsistent with the view that the adipose fin lacks function. Research published in 2014 indicates that the adipose fin has evolved repeatedly in separate lineages . (A) - Heterocercal means
Albacore - Misplaced Pages Continue
5082-504: Is the contraction of Kinki University in Japanese (Kinki daigaku). In 2009, Clean Seas, an Australian company which has been receiving assistance from Kinki University managed to breed southern bluefin tuna in captivity and was awarded the second place in World's Best Invention of 2009 by Time magazine. The fresh or frozen flesh of tuna is widely regarded as a delicacy in most areas where it
5203-433: Is the heterocercal tail, which aids in locomotion. Most sharks have eight fins. Sharks can only drift away from objects directly in front of them because their fins do not allow them to move in the tail-first direction. Unlike modern cartilaginous fish, members of stem chondrichthyan lineages (e.g. the † climatiids and the † diplacanthids ) possessed pectoral dermal plates as well as dermal spines associated with
5324-400: Is the largest class of vertebrates in existence today, making up more than 50% of species. In the distant past, lobe-finned fish were abundant; however, there are currently only 8 species. Bony fish have fin spines called lepidotrichia or "rays" (due to how the spines spread open). They typically have swim bladders , which allow the fish to alter the relative density of its body and thus
5445-587: Is thought that their rostral organ helps give the coelacanth electroperception, which aids in their movement around obstacles. Lungfish are also living lobe-finned fish. They occur in Africa ( Protopterus ), Australia ( Neoceratodus ), and South America ( Lepidosiren ). Lungfish evolved during the Devonian Period. Genetic studies and paleontological data confirm that lungfish are the closest living relatives of land vertebrates . Fin arrangement and body shape
5566-512: Is usually oil or water. The product became more plentiful in the United States in the late 1940s. In 1950, 8,500,000 pounds of canned tuna were produced, and the U.S. Department of Agriculture classified it as a "plentiful food". In the United States, 52% of canned tuna is used for sandwiches ; 22% for tuna salads ; and 15% for tuna casseroles and dried, prepackaged meal kits , such as General Mills 's Tuna Helper line. Other canned tuna dishes include tuna melts (a type of sandwich where
5687-510: The Atlantic bluefin tuna , that name in turn is ultimately derived from θύνω thýnō , meaning "to rush, dart along". In English, tuna has been referred to as Chicken of the Sea . This name persists today in Japan, where tuna as a food can be called シーチキン ( shi-chikin ) , literally "sea chicken". The Thunnini tribe is a monophyletic clade comprising 15 species in five genera : The cladogram
5808-831: The California Current with the season lasting from mid-July until October. Albacore are managed by four tuna Regional Fisheries Management Organizations (RFMO's): the Western and Central Pacific Fisheries Commission (WCPFC), the Inter-American Tropical Tuna Commission (IATTC), the International Commission for the Conservation of Atlantic Tunas (ICCAT), and the Indian Ocean Tuna Commission (IOTC). ICCAT has established catch quotas in
5929-572: The Humane Society International , approximately 100 million sharks are killed each year for their fins, in an act known as shark finning . After the fins are cut off, the mutilated sharks are thrown back in the water and left to die. In some countries of Asia , shark fins are a culinary delicacy, such as shark fin soup . Currently, international concerns over the sustainability and welfare of sharks have impacted consumption and availability of shark fin soup worldwide. Shark finning
6050-477: The Middle Triassic † Saurichthys , the oldest known example of viviparity in a ray-finned fish. Claspers are found on the males of cartilaginous fishes . They are the posterior part of the pelvic fins that have also been modified to function as intromittent organs, and are used to channel semen into the female's cloaca during copulation. The act of mating in sharks usually includes raising one of
6171-529: The Pacific Ocean , 22 percent from the Indian Ocean , and the remaining 10 percent from the Atlantic Ocean and the Mediterranean Sea . Skipjack makes up about 60 percent of the catch, followed by yellowfin (24 percent), bigeye (10 percent), albacore (5 percent), and bluefin the remainder. Purse-seines take about 62 percent of the world production, longline about 14 percent, pole and line about 11 percent, and
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#17328547767756292-472: The arterial blood via a counter-current exchange system, thus mitigating the effects of surface cooling. This allows the tuna to elevate the temperatures of the highly- aerobic tissues of the skeletal muscles, eyes and brain, which supports faster swimming speeds and reduced energy expenditure, and which enables them to survive in cooler waters over a wider range of ocean environments than those of other fish. Also unlike most fish, which have white flesh,
6413-408: The bullet tuna (max length: 50 cm or 1.6 ft, weight: 1.8 kg or 4 lb) up to the Atlantic bluefin tuna (max length: 4.6 m or 15 ft, weight: 684 kg or 1,508 lb), which averages 2 m (6.6 ft) and is believed to live up to 50 years. Tuna, opah , and mackerel sharks are the only species of fish that can maintain a body temperature higher than that of
6534-417: The buoyancy , so it can sink or float without having to use the fins to swim up and down. However, swim bladders are absent in many fish, most notably in lungfishes , who have evolved their swim bladders into primitive lungs , which may have a shared evolutionary origin with those of their terrestrial relatives, the tetrapods . Bony fishes also have a pair of opercula that function to draw water across
6655-409: The extinct † Petalodontiformes (e.g. † Belantsea , † Janassa , † Menaspis ), which belong to Holocephali (ratfish and their fossil relatives), or in † Aquilolamna ( Selachimorpha ) and † Squatinactis (Squatinactiformes). Some cartilaginous fishes have an eel-like locomotion (e.g. Chlamydoselachus , † Thrinacoselache , † Phoebodus ) According to
6776-426: The gills , which help them breathe without needing to swim forward to force the water into the mouth across the gills. Lobe-finned fishes form a class of bony fishes called Sarcopterygii. They have fleshy, lobed , paired fins, which are joined to the body by a series of bones. The fins of lobe-finned fish differ from those of all other fish in that each is borne on a fleshy, lobe-like, scaly stalk extending from
6897-831: The midsagittal unpaired fins and the more laterally located paired fins . Unpaired fins are predominantly associated with generating linear acceleration via oscillating propulsion , as well as providing directional stability ; while paired fins are used for generating paddling acceleration , deceleration, and differential thrust or lift for turning , surfacing or diving and rolling . Fins can also be used for other locomotions other than swimming, for example, flying fish use pectoral fins for gliding flight above water surface, and frogfish and many amphibious fishes use pectoral and/or pelvic fins for crawling . Fins can also be used for other purposes: remoras and gobies have evolved sucker -like dorsal fins for attaching to surfaces and "hitchhiking"; male sharks and mosquitofish use
7018-417: The skipjack tuna , yellowfin tuna , and bluefin tuna . Once grown, schools are highly migratory. The albacore is a very economically important fish and is a target of commercial and recreational fisheries. It was originally the basis for the United States tuna-canning industry and is no less important today, making up significant percentages of the gross domestic products of various Pacific nations. It
7139-471: The ventral portion. This is because the shark's vertebral column extends into that dorsal portion, providing a greater surface area for muscle attachment. This allows more efficient locomotion among these negatively buoyant cartilaginous fish. By contrast, most bony fish possess a homocercal caudal fin. Tiger sharks have a large upper lobe , which allows for slow cruising and sudden bursts of speed. The tiger shark must be able to twist and turn in
7260-412: The 20th century. The migratory patterns of the fish brought droves of albacore schools near the coastline of southern California, which sparked the start of commercial albacore fishing. In 1903, 700 cases of albacore were used as an experimental pack which ultimately led to the development of the U.S. tuna-canning industry. The experiment was a huge success, and the commercial fishery expanded rapidly due to
7381-636: The North Pacific. Through these studies we have learned that juvenile albacore (to 2 years of age) make trans-Pacific migrations in their younger years between Japan and the West coast of North America. To date over 24,000 albacore have been tagged with conventional dart tags and 1,245 of these have been recovered. In Spring of 2001 AFRF and the SWFSC began a pilot project to learn more about the migration habits of North Pacific albacore, Thunnus alalunga in an effort to allow
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#17328547767757502-570: The North and South Atlantic. There are six globally managed stocks of albacore worldwide, one in the North Pacific, one in the South Pacific, another in the Indian Ocean, two for the North and South Atlantic, and one in the Mediterranean Sea. There is substantial uncertainty on current stock status, since different models and assumptions provide a wide range of estimates. However, most of them agreed on
7623-646: The Northeast Pacific: one off the northern part of Baja California , Mexico, and the other off the coasts of Washington and Oregon . Every summer, North Atlantic albacore head to the Bay of Biscay off of France and Spain , but now arrive about 8 days earlier than they did 40 years ago. Since the 1970s the NOAA Fisheries, Southwest Fisheries Science Center (SWFSC) has collaborated with American Fishermen's Research Foundation (AFRF) in tagging studies of albacore in
7744-705: The South Pacific Albacore are not overfished. In the 2014 assessment, the Albacore Working Group of the International Scientific Committee for Tuna and Tuna-like Species in North Pacific Ocean found estimates of total stock biomass (age-1 and older) show a long-term decline from the early 1970s to 1990 followed by a recovery through the 1990s and subsequent fluctuations without trend in the 2000s. The working group concludes that
7865-434: The ability to lock their spines outwards. Triggerfish also use spines to lock themselves in crevices to prevent them being pulled out. Lepidotrichia are usually composed of bone , but those of early osteichthyans - such as Cheirolepis - also had dentine and enamel . They are segmented and appear as a series of disks stacked one on top of another. They may have been derived from dermal scales. The genetic basis for
7986-641: The albacore was authored in 1788 by Pierre Joseph Bonnaterre in the illustrated encyclopedia Tableau encyclopédique et methodique des trois règnes de la nature . He originally placed it in the mackerel genus Scomber . It was assigned to the genus Thunnus by ichthyologists Bruce B. Collette and Cornelia E. Nauen in 1983. It is a member of the Thunnus subgenus , also known as the bluefin group. Populations of albacore differ genetically by region, with Atlantic, Pacific, and Mediterranean groups each showing differences in mitochondrial and nuclear DNA . The albacore has
8107-513: The base of the pectoral fins. Both dorsal and pelvic fins retract when the fish is swimming fast. The tuna's body is countershaded to camouflage itself in deeper water when seen from above, its dorsal side is generally a metallic dark blue while the ventral or under side is silvery, often with an iridescent shine. The caudal peduncle , to which the tail is attached, is quite thin, with three stabilizing horizontal keels on each side. Thunnus are widely but sparsely distributed throughout
8228-427: The body of fish that interact with water to generate thrust and help the fish swim . Apart from the tail or caudal fin , fish fins have no direct connection with the back bone and are supported only by muscles . Fish fins are distinctive anatomical features with varying structures among different clades : in ray-finned fish ( Actinopterygii ), fins are mainly composed of bony spines or rays covered by
8349-514: The body. Pectoral and pelvic fins have articulations resembling those of tetrapod limbs. These fins evolved into legs of the first tetrapod land vertebrates ( amphibians ) in the Devonian Period . Sarcopterygians also possess two dorsal fins with separate bases, as opposed to the single dorsal fin of most ray-finned fish (except some teleosts ). The caudal fin is either heterocercal (only fossil taxa ) or diphycercal. The coelacanth
8470-548: The claspers to allow water into a siphon through a specific orifice . The clasper is then inserted into the cloaca, where it opens like an umbrella to anchor its position. The siphon then begins to contract expelling water and sperm. Other uses of fins include walking and perching on the sea floor, gliding over water, cooling of body temperature, stunning of prey, display (scaring of predators, courtship), defence (venomous fin spines, locking between corals), luring of prey, and attachment structures. The Indo-Pacific sailfish has
8591-412: The coasts of Washington, Oregon, and California have far lower mercury levels than in previous years. Albacore caught in this region also show methylmercury levels well below the 1.0 ppm mercury standard set by The U.S. Food and Drug Administration (FDA). Nevertheless, since mercury does take time to be removed from the body, albacore tuna should be eaten in moderation. As with other tunas, albacore meat
8712-465: The current and drift. They use their paired fins to stabilize their movement through the water. While on the ocean floor their paired fins are not used for any kind of movement. Coelacanths can create thrust for quick starts by using their caudal fins. Due to the high number of fins they possess, coelacanths have high maneuverability and can orient their bodies in almost any direction in the water. They have been seen doing headstands and swimming belly up. It
8833-738: The dorsal surface and no dorsal fin). In some fish such as tuna or sauries , they are rayless, non-retractable, and found between the last dorsal and/or anal fin and the caudal fin. Bony fishes ( Actinopterygii and Sarcopterygii ) form a taxonomic group called Osteichthyes (or Euteleostomi , which includes also land vertebrates ); they have skeletons made of bone mostly, and can be contrasted with cartilaginous fishes (see below), which have skeletons made mainly of cartilage (except for their teeth , fin spines , and denticles ). Bony fishes are divided into ray-finned and lobe-finned fish . Most living fish are ray-finned, an extremely diverse and abundant group consisting of over 30,000 species . It
8954-525: The dorsal, anal and caudal fins are unpaired and situated along the midline of the body. For every type of fin, there are a number of fish species in which this particular fin has been lost during evolution (e.g. pelvic fins in † Bobasatrania , caudal fin in ocean sunfish ). In some clades , additional unpaired fins were acquired during evolution (e.g. additional dorsal fins, adipose fin). In some † Acanthodii ("spiny sharks"), one or more pairs of "intermediate" or "prepelvic" spines are present between
9075-554: The epipelagic and mesopelagic zones. It is most often found in surface waters 15.6–19.4 °C (60.1–66.9 °F) in temperature, though larger individuals can be found in deeper waters 13.5–25.2 °C (56.3–77.4 °F). It can survive at temperatures as low as 9.5 °C (49.1 °F) for short periods of time. It favors areas where warm and cool water mix. A highly migratory species, schools of albacore travel great distances, though Atlantic and Pacific populations do not appear to mix. North Pacific albacore migrate to two regions of
9196-402: The equator. The albacore is a powerful, hard-hitting predator that forms mixed schools with skipjack tuna , yellowfin tuna , and bluefin tuna , sometimes around floating objects like sargassum weeds. Schools of albacore are highly migratory within bodies of water and segregated by maturity, with older fish tending to form more compact groups. Of those caught by humans, immature albacore have
9317-442: The female. The male shortly inserts the organ into the sex opening of the female, with hook-like adaptations that allow the fish to grip onto the female to ensure impregnation. If a female remains stationary and her partner contacts her vent with his gonopodium, she is fertilized. The sperm is preserved in the female's oviduct. This allows females to fertilize themselves at any time without further assistance from males. In some species,
9438-399: The fins are dark blue on top, but change to a medium yellow color on the underside. They are markedly shorter in fish under 0.5 m (1 ft 8 in) in length, often resulting in confusion with T. obesus juveniles, which also have long pectoral fins, though these are rounded at the tips where the albacore's taper to a point. The first dorsal fin is a deep yellow and the second, which
9559-414: The first U.S. offshore farming of bigeye tuna in water 1,300 feet (400 m) deep in 2009. Japan is the biggest tuna consuming nation and is also the leader in tuna farming research. Japan first successfully farm-hatched and raised bluefin tuna in 1979. In 2002, it succeeded in completing the reproduction cycle and in 2007, completed a third generation. The farm breed is known as Kindai tuna. Kindai
9680-400: The first dorsal fin spine was modified, forming a spine-brush complex. As with most fish, the tails of sharks provide thrust, making speed and acceleration dependent on tail shape. Caudal fin shapes vary considerably between shark species, due to their evolution in separate environments. Sharks possess a heterocercal caudal fin in which the dorsal portion is usually noticeably larger than
9801-501: The formation of a linked chain of vortex rings" and that "the dorsal and anal fin wakes are rapidly entrained by the caudal fin wake, approximately within the timeframe of a subsequent tail beat". Once motion has been established, the motion itself can be controlled with the use of other fins. The bodies of reef fishes are often shaped differently from open water fishes . Open water fishes are usually built for speed, streamlined like torpedoes to minimise friction as they move through
9922-553: The formation of the fin rays is thought to be genes coded for the production of certain proteins. It has been suggested that the evolution of the tetrapod limb from lobe-finned fishes is related to the loss of these proteins. Cartilaginous fishes form a class of fishes called Chondrichthyes. They have skeletons made of cartilage rather than bone . The class includes sharks , rays and chimaeras . Shark fin skeletons are elongated and supported with soft and unsegmented rays named ceratotrichia, filaments of elastic protein resembling
10043-592: The genus Thunnus . Until recently, it was thought that there were seven Thunnus species, and that 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. The genus Thunnus is further classified into two subgenera : Thunnus ( Thunnus ) (the bluefin group), and Thunnus ( Neothunnus ) (the yellowfin group). The Thunnini tribe also includes seven additional species of tuna across four genera. They are: The tuna
10164-510: The gonopodium may be half the total body length. Occasionally the fin is too long to be used, as in the "lyretail" breeds of Xiphophorus helleri . Hormone treated females may develop gonopodia. These are useless for breeding. Similar organs with similar characteristics are found in other fishes, for example the andropodium in the Hemirhamphodon or in the Goodeidae or the gonopodium in
10285-684: The gross domestic product in four PICTs. License fees from foreign ships provide an average of 3–40% of government revenue for seven different PICTs. Processing facilities and tuna fishing vessels provide more than 12,000 jobs for workers in the Pacific islands. Fish provide 50–90% of dietary animal protein in rural areas of PICTs. Albacore are sought after by sport fishers . Since 2000, a large recreational fishery for albacore has been established in Oregon, Washington and California. The fisheries in Oregon and Washington are supported by seasonal warm water influxes from
10406-480: The high level of demand for canned tuna. By the 1920s, the industry expanded further and three other species of tuna—bluefin, yellowfin, and skipjack—were also being canned. Albacore tuna is the only species that can be marketed as "white meat tuna". The canning industry uses this label to differentiate canned albacore from other types of tuna. From 2010 to 2013, a study by Oceana , an ocean preservation organization, tested over 114 samples of tuna, and found that 84% of
10527-410: The horny keratin in hair and feathers. Originally the pectoral and pelvic girdles, which do not contain any dermal elements, did not connect. In later forms, each pair of fins became ventrally connected in the middle when scapulocoracoid and puboischiadic bars evolved. In rays , the pectoral fins have connected to the head and are very flexible. One of the primary characteristics present in most sharks
10648-428: The incorporation of detailed migration movements into stock assessment models. Archival tags are a recent technical innovation that are being used to collect daily locations (through light level data recorded by the tag), internal temperature of the fish's abdomen, ambient water temperature, and depth. Genetic research using ddRAD sequencing indicates that albacore migrate between the North and South Pacific oceans across
10769-443: The lateral fin-fold theory, first suggested in 1877, which proposes that paired fins budded from longitudinal, lateral folds along the epidermis just behind the gills. There is weak support for both hypotheses in the fossil record and in embryology. However, recent insights from developmental patterning have prompted reconsideration of both theories in order to better elucidate the origins of paired fins. Carl Gegenbaur 's concept of
10890-493: The males of some species in the Anablepidae and Poeciliidae families. They are anal fins that have been modified to function as movable intromittent organs and are used to impregnate females with milt during mating. The third, fourth and fifth rays of the male's anal fin are formed into a tube-like structure in which the sperm of the fish is ejected. When ready for mating, the gonopodium becomes erect and points forward towards
11011-458: The margin at the rear of their bodies is a line of small rayless, non-retractable fins, known as finlets . There has been much speculation about the function of these finlets. Research done in 2000 and 2001 by Nauen and Lauder indicated that "the finlets have a hydrodynamic effect on local flow during steady swimming" and that "the most posterior finlet is oriented to redirect flow into the developing tail vortex, which may increase thrust produced by
11132-592: The most sought-after stocks to the brink of commercial extinction unless fisheries agree on more rigid quotas". Japan's Fisheries Research Agency counters that Australian and New Zealand tuna fishing companies under-report their total catches of southern bluefin tuna and ignore internationally mandated total allowable catch totals. In recent years, opening day fish auctions at Tokyo's Tsukiji fish market and Toyosu Market have seen record-setting prices for bluefin tuna, reflecting market demand. In each of 2010, 2011, 2012, 2013 and 2019, new record prices have been set for
11253-552: The most widely accepted of these programs is that of the Marine Stewardship Council (MSC). Several albacore fisheries have been certified as sustainable according to MSC standards, including the U.S. North and South Pacific albacore pole and line and troll/jig fisheries ("pole and troll"), Canadian North Pacific troll fishery, and the New Zealand South Pacific troll fishery. SeaChoice ranks albacore as
11374-444: The muscle tissue of tuna ranges from pink to dark red. The red myotomal muscles derive their color from myoglobin , an oxygen-binding molecule, which tuna express in quantities far higher than most other fish. The oxygen-rich blood further enables energy delivery to their muscles. For powerful swimming animals like dolphins and tuna, cavitation may be detrimental, because it limits their maximum swimming speed. Even if they have
11495-504: The oceans of the world, generally in tropical and temperate waters at latitudes ranging between about 45° north and south of the equator. All tunas are able to maintain the temperature of certain parts of their body above the temperature of ambient seawater. For example, bluefin can maintain a core body temperature of 25–33 °C (77–91 °F), in water as cold as 6 °C (43 °F). Unlike other endothermic creatures such as mammals and birds, tuna do not maintain temperature within
11616-409: The oogonial nests of female tuna. The resulting oocytes are cast en masse into the sea, where full development and later fertilization take place. Albacore is a prized food, and the albacore fishery is economically significant. Methods of fishing include pole and line , long-line fishing , trolling , and some purse seining . The harvest of albacore tuna for commercial use began at the start of
11737-690: The paired fins. The oldest species demonstrating these features is the † acanthodian † Fanjingshania renovata from the lower Silurian ( Aeronian ) of China. Fanjingshania possess compound pectoral plates composed of dermal scales fused to a bony plate and fin spines formed entirely of bone. Fin spines associated with the dorsal fins are rare among extant cartilaginous fishes, but are present, for instance, in Heterodontus or Squalus . Dorsal fin spines are typically developed in many fossil groups, such as in † Hybodontiformes , † Ctenacanthiformes or † Xenacanthida . In † Stethacanthus ,
11858-403: The pectoral and pelvic fins, but these are not associated with fins. The pelvic fin assists the fish in going up or down through the water, turning sharply, and stopping quickly. The dorsal fins are located on the back. A fish can have up to three dorsal fins. The dorsal fins serve to protect the fish against rolling, and assist it in sudden turns and stops. The function of the adipose fin
11979-453: The pod with nets to catch the tuna beneath. The nets were prone to entangling dolphins, injuring or killing them. Public outcry and new government regulations, which are now monitored by NOAA have led to more dolphin-friendly methods, now generally involving lines rather than nets. There are neither universal independent inspection programs nor verification of dolphin safety, so these protections are not absolute. According to Consumers Union ,
12100-513: The power to swim faster, dolphins may have to restrict their speed, because collapsing cavitation bubbles on their tail are too painful. Cavitation also slows tuna, but for a different reason. Unlike dolphins, these fish do not feel the bubbles, because they have bony fins without nerve endings. Nevertheless, they cannot swim faster because the cavitation bubbles create a vapor film around their fins that limits their speed. Lesions have been found on tuna that are consistent with cavitation damage. Tuna
12221-529: The public demand to protect dolphins can be potentially damaging to other species as well. Increasing quantities of high-grade tuna caught at sea are reared in net pens and fed bait fish. In Australia, former fishermen raise southern bluefin tuna ( Thunnus maccoyii ) and another bluefin species. Farming its close relative, the Atlantic bluefin tuna , Thunnus thynnus , is beginning in the Mediterranean , North America and Japan. Hawaiʻi approved permits for
12342-414: The report states: Between 1940 and the mid-1960s, the annual world catch of the five principal market species of tunas rose from about 300 thousand tons to about 1 million tons, most of it taken by hook and line . With the development of purse-seine nets, now the predominant gear, catches have risen to more than 4 million tons annually during the last few years. Of these catches, about 68 percent are from
12463-499: The resulting lack of accountability means claims of tuna that is " dolphin safe " should be given little credence. Fishery practices have changed to be dolphin friendly, which has caused greater bycatch including sharks , turtles and other oceanic fish . Fishermen no longer follow dolphins, but concentrate their fisheries around floating objects such as fish aggregation devices , also known as FADs, which attract large populations of other organisms. Measures taken thus far to satisfy
12584-423: The southern Atlantic stock to be overfished but not currently experiencing overfishing. They regarded North Pacific albacore stocks as not overfished and not likely to be experiencing overfishing. Like other fish, albacore accumulate methylmercury in body tissue over time. Methylmercury is removed from the human body naturally, but it may take over a year for the levels to drop significantly. Thus, it may remain in
12705-402: The spiny rays are always anterior . Spines are generally stiff and sharp. Rays are generally soft, flexible, segmented, and may be branched. This segmentation of rays is the main difference that separates them from spines; spines may be flexible in certain species, but they will never be segmented. Spines have a variety of uses. In catfish , they are used as a form of defense; many catfish have
12826-520: The stock is likely not in an overfished condition at present. South Pacific albacore stocks have recently (2007 to 2015) shown a 40% reduction in stock. Population genomic research supports the distinction of separate North and South Pacific stocks, but results indicated that interbreeding occurs between these populations and some potential migrants were genetically identified. A number of programs have been developed to help consumers identify and support responsible and sustainable fisheries . Perhaps
12947-403: The summer. Due to climate changes over the last 40 years, the timing and spatial distribution of the albacore have also changed. Albacore show a broad range of behavioral differences by region. In Baja California , albacore make frequent dives to depths exceeding 200 m (660 ft) during the day and stay near the surface at night, while off the coast of Washington and Oregon they stay near
13068-408: The surface the entire day. Albacore never really rest; their need for oxygen means they must always be on the move. Albacore tuna are pelagic predators - open-sea hunters. Their diets vary very little from season to season. Unlike other tuna that eat primarily fish, for example the bigeye and yellowfin tuna, the albacore's main source of food is cephalopods . The most abundant cephalopod in its diet
13189-437: The surrounding water . An active and agile predator , the tuna has a sleek, streamlined body, and is among the fastest-swimming pelagic fish – the yellowfin tuna , for example, is capable of speeds of up to 75 km/h (47 mph). Greatly inflated speeds can be found in early scientific reports and are still widely reported in the popular literature. Found in warm seas, the tuna is commercially fished extensively as
13310-552: The tail of swimming mackerel". Fish use multiple fins, so it is possible that a given fin can have a hydrodynamic interaction with another fin. In particular, the fins immediately upstream of the caudal (tail) fin may be proximate fins that can directly affect the flow dynamics at the caudal fin. In 2011, researchers using volumetric imaging techniques were able to generate "the first instantaneous three-dimensional views of wake structures as they are produced by freely swimming fishes". They found that "continuous tail beats resulted in
13431-450: The tip of the tail and the tail is symmetrical but not expanded (as in the first fishes and the cyclostomes , and a more primitive precursor in lancelets ) (C) - Homocercal where the fin usually appears superficially symmetric but in fact the vertebrae extend for a very short distance into the upper lobe of the fin. Homocercal caudal fins can, however, also appear asymmetric (e.g. blue flying fish ). Most modern fishes ( teleosts ) have
13552-490: The tuna is mixed with mayonnaise and served on bread with cheese melted on top); salade niçoise (a salad made of tuna, olives, green beans, potatoes, hard-boiled eggs and anchovy dressing); and tuna burgers (served on buns). In the United States, the Food and Drug Administration (FDA) regulates canned tuna (see part c ). Caudal fin Fins are moving appendages protruding from
13673-434: The tuna, and holding it at 4 °C. For a 2-inch tuna steak, this requires 24 hours. The fish is then vacuum sealed and frozen. In Japan, color fixation using CO is prohibited. Tuna is canned in edible oils , in brine , in water, and in various sauces. Tuna may be processed and labeled as "solid", "chunked" ("chunk") or "flaked". When tuna is canned and packaged for sale, the product is sometimes called tuna fish (U.S.),
13794-683: The tunas), and that the next nearest relatives of the tunas are the bonitos of the tribe Sardini. Butterfly kingfishes (one genus) Mackerels (two genera) [REDACTED] Spanish mackerels (three genera) [REDACTED] Bonitos (four genera) [REDACTED] Allothunnus , slender tunas Auxis , frigate tunas [REDACTED] Euthynnus , little tunas [REDACTED] Katsuwonus , skipjack tunas [REDACTED] bluefin group [REDACTED] yellowfin group [REDACTED] The "true" tunas are those that belong to
13915-419: The vertebrae extend into the upper lobe of the tail, often making it longer than the lower lobe (as in sharks , † Placodermi , most stem Actinopterygii , and sturgeons and paddlefish ). However, the external shape of heterocercal tail fins can also appear symmetric (e.g. † Birgeria , † Bobasatrania ). Heterocercal is the opposite of hypocercal (B) - Protocercal means the vertebrae extend to
14036-412: The view that spawning stock biomass decreased since the 1930s and started to recover since the mid-1990s. Most of the model formulations, as well as the base case, concluded that currently the stock is not undergoing overfishing but the spawning stock biomass is overfished. IOTC judges albacore in the Indian Ocean are not overfished, but maintaining or increasing effort in the core albacore fishing grounds
14157-511: The water easily when hunting to support its varied diet, whereas the porbeagle shark , which hunts schooling fish such as mackerel and herring , has a large lower lobe to help it keep pace with its fast-swimming prey. Other tail adaptations help sharks catch prey more directly, such as the thresher shark 's usage of its powerful, elongated upper lobe to stun fish and squid. On the other hand, rays rely on their enlarged pectoral fins for propulsion. Similarly enlarged pectoral fins can be found in
14278-697: The water. Reef fish operate in the relatively confined spaces and complex underwater landscapes of coral reefs . For this manoeuvrability is more important than straight line speed, so coral reef fish have developed bodies which optimize their ability to dart and change direction. They outwit predators by dodging into fissures in the reef or playing hide and seek around coral heads. The pectoral and pelvic fins of many reef fish, such as butterflyfish , damselfish and angelfish , have evolved so they can act as brakes and allow complex manoeuvres. Many reef fish, such as butterflyfish , damselfish and angelfish , have evolved bodies which are deep and laterally compressed like
14399-408: The white tuna samples were actually escolar . Many Pacific island countries and territories (PICTs) heavily rely on oceanic fisheries for economic development and food security. The albacore is one of the main four species of tuna that support oceanic fisheries along with the skipjack, yellowfin, and the bigeye tunas. Domestic tuna fleets and local fish processing operations contribute from 3–20% of
14520-522: The “Archipterygium” was introduced in 1876. It was described as a gill ray, or "joined cartilaginous stem," that extended from the gill arch. Additional rays arose from along the arch and from the central gill ray. Gegenbaur suggested a model of transformative homology – that all vertebrate paired fins and limbs were transformations of the Archipterygium. Based on this theory, paired appendages such as pectoral and pelvic fins would have differentiated from
14641-583: Was listed as Near Threatened by the International Union for Conservation of Nature (IUCN) because of the threat of overfishing but is now Least Concern again. Several stocks were in significant decline and the species' overall population were decreasing but are now recovering thanks to the enforcement of regional fishing quotas. T. atlanticus T. albacares T. tonggol T. obesus T. maccoyii T. thynnus T. alalunga T. orientalis The first scientific description of
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