159-630: Air Jaws is a series of fifteen TV specials about great white sharks that have aired on Discovery Channel 's Shark Week . The specials are mainly filmed in the Indian Ocean off the coast of South Africa , many on Seal Island in False Bay , near Cape Town , or in Mossel Bay . All fifteen specials were produced and directed by Jeff Kurr. The third episode "Ultimate Air Jaws" was nominated for an Emmy, Outstanding Individual Achievement in
318-500: A velvety texture. Each denticle has three horizontal ridges that lead to teeth on the posterior margin. The dorsal coloration is a medium to dark gray or slate, extending to the bases of the pectoral fins. The underside is white; adults in the Southern Hemisphere often have dark coloring under the head and dusky blotches scattered over the belly. The free rear tip of the first dorsal fin is abruptly light gray or white,
477-637: A 1.8 m (5.9 ft) juvenile male pygmy sperm whale ( Kogia breviceps ) was found stranded in central California with a bite mark on its caudal peduncle from a great white shark. In addition, white sharks attack and prey upon beaked whales . Cases where an adult Stejneger's beaked whale ( Mesoplodon stejnegeri ), with a mean mass of around 1,100 kg (2,400 lb), and a juvenile Cuvier's beaked whale ( Ziphius cavirostris ), an individual estimated at 3 m (9.8 ft), were hunted and killed by great white sharks have also been observed. When hunting sea turtles, they appear to simply bite through
636-522: A 2014 study, the lifespan of great white sharks is estimated to be as long as 70 years or more, well above previous estimates, making it one of the longest lived cartilaginous fishes currently known. According to the same study, male great white sharks take 26 years to reach sexual maturity, while the females take 33 years to be ready to produce offspring. Great white sharks can swim at speeds of 25 km/h (16 mph) for short bursts and to depths of 1,200 m (3,900 ft). The great white shark
795-472: A 4.5 m (15 ft) white shark for 1.5 months. Detailed observations were made of four whale carcasses in False Bay between 2000 and 2010. Sharks were drawn to the carcass by chemical and odour detection, spread by strong winds. After initially feeding on the whale caudal peduncle and fluke , the sharks would investigate the carcass by slowly swimming around it and mouthing several parts before selecting
954-413: A Craft: Cinematography - Nature in 2011. This article related to a made-for-TV documentary film is a stub . You can help Misplaced Pages by expanding it . Great white shark The great white shark ( Carcharodon carcharias ), also known as the white shark , white pointer , or simply great white , is a species of large mackerel shark which can be found in the coastal surface waters of all
1113-409: A bit less since they are more slender in build than a great white) in exceptional cases. Great white sharks, like all other sharks, have an extra sense given by the ampullae of Lorenzini which enables them to detect the electromagnetic field emitted by the movement of living animals. Great whites are so sensitive they can detect variations of half a billionth of a volt . At close range, this allows
1272-464: A blubber-rich area. During feeding bouts of 15–20 seconds the sharks removed flesh with lateral headshakes, without the protective ocular rotation they employ when attacking live prey. The sharks were frequently observed regurgitating chunks of blubber and immediately returning to feed, possibly in order to replace low energy yield pieces with high energy yield pieces, using their teeth as mechanoreceptors to distinguish them. After feeding for several hours,
1431-433: A broad, unserrated teeth is uncertain. Tracing beyond C. hastalis , another prevailing hypothesis proposes that the great white and mako lineages shared a common ancestor in a primitive mako-like species. The identity of this ancestor is still debated, but a potential species includes Isurolamna inflata , which lived between 65 and 55 million years ago. It is hypothesized that the great white and mako lineages split with
1590-405: A brown or blue shade) that gives an overall mottled appearance. The coloration makes it difficult for prey to spot the shark because it breaks up the shark's outline when seen from the side. From above, the darker shade blends with the sea and from below it exposes a minimal silhouette against the sunlight. Leucism is extremely rare in this species, but has been documented at least three times; in
1749-632: A detailed population model and concluded that a quota of 200–250 tons would allow for population growth, resulting in a quota of 250 tons being adopted for the period of 2002–2007. The mating grounds off Newfoundland were also closed to shark fishing. In 2004, the Committee on the Status of Endangered Wildlife in Canada listed the porbeagle as endangered, largely on the basis of the low population abundance (<25% of original numbers). Canada decided not to list
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#17327826821241908-468: A distinct type of animal appears in Pierre Belon 's 1553 book De aquatilibus duo, cum eiconibus ad vivam ipsorum effigiem quoad ejus fieri potuit, ad amplissimum cardinalem Castilioneum . In it, he illustrated and described the shark under the name Canis carcharias based on the jagged nature of its teeth and its alleged similarities with dogs . Another name used for the great white around this time
2067-562: A feature unique to this species. The porbeagle may attain a length of 3.7 m (12 ft), though this is uncertain and may have resulted from confusion with other mackerel shark species. A more typical length is 2.5 m (8.2 ft). Female sharks grow larger than males in the North Atlantic, with maximum confirmed fork lengths (snout tip to caudal fin fork) of 2.5 m (8.2 ft) for males and 3.0 m (9.8 ft) for females. Southern Hemisphere sharks are smaller and
2226-481: A few shark attacks of uncertain provenance have been attributed to the porbeagle. It is well regarded as a game fish by recreational anglers . The meat and fins of the porbeagle are highly valued, which has led to a long history of intense human exploitation. However, this species cannot sustain heavy fishing pressure due to its low reproductive capacity. Direct commercial fishing for the porbeagle, principally by Norwegian longliners , led to stock collapses in
2385-753: A few dozen specimens have been recorded in the past few decades, from scientific surveys, swordfish fishery bycatch, and sport fishers. In 1995, it was included in Annex III ("species whose exploitation is regulated") of the Barcelona Convention Protocol on protected areas and biodiversity in the Mediterranean, which has not been ratified. In 1997, it was listed on Appendix III of the Bern Convention (the Convention on
2544-523: A fork length of 2.0–2.2 m (6.6–7.2 ft) and an age of 12–18 years. In the Southwest Pacific, males mature at a fork length of 1.4–1.5 m (4.6–4.9 ft) and an age of 8–11 years, and females at a fork length of 1.7–1.8 m (5.6–5.9 ft) and an age of 15–18 years. The oldest porbeagle on record was 26 years of age and measured 2.5 m (8.2 ft) long. The maximum lifespan of this species appears to be 30–40 years in
2703-400: A great white approaches too closely to another, they react with a warning bite. Another possibility is that white sharks bite to show their dominance. Data acquired from animal-borne telemetry receivers and published in 2022 via the journal Royal Society Publishing suggests that individual great whites may associate so that they can inadvertently share information on the whereabouts of prey or
2862-601: A high content of energy-rich fat. Shark expert Peter Klimley used a rod-and-reel rig and trolled carcasses of a seal, a pig, and a sheep from his boat in the South Farallons . The sharks attacked all three baits but rejected the sheep carcass. Off Seal Island , False Bay in South Africa, the sharks ambush brown fur seals ( Arctocephalus pusillus ) from below at high speeds, hitting the seal mid-body. They achieve high speeds that allow them to completely breach
3021-432: A length of 58 cm (23 in). By then, its stomach has shrunk enough for the abdominal muscles to close, leaving what has been termed an "umbilical scar" or "yolk sac scar" (neither is accurate). Several series of single-cusped teeth grow in both jaws, though they lie flat and remain nonfunctional until birth. Newborn porbeagles measure 58–67 cm (23–26 in) long and do not exceed 5 kg (11 lb). Up to
3180-538: A more positive prospect than in the eastern North Atlantic. Fishing in Canadian waters was originally regulated by the 1995 Fisheries Management Plan for pelagic sharks in Atlantic Canada, which established an annual quota of 1,500 tons, restricted the time, place, and gear types allowed for commercial fishing, and set limits for bycatch and recreational fishing. In 2000–2001, Fisheries and Oceans Canada prepared
3339-485: A population study in 2014; since 2019, this research has focused on how humans can avoid conflict with sharks. Scientists believe all North Atlantic great white sharks spend their first year of life near New York City, off the coast of Long Island. A 2018 study indicated that white sharks prefer to congregate deep in anticyclonic eddies in the North Atlantic Ocean . The sharks studied tended to favour
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#17327826821243498-584: A porbeagle into leaping from the water and tearing his clothes. In another account of a swimmer bitten by a "mackerel shark", the species responsible could easily have been a misidentified shortfin mako or great white shark. Recently in the North Sea , adult porbeagles have been filmed charging at divers working on oil platforms , sometimes even brushing lightly against them without doing harm. These rushes do not appear to have predatory intent and may instead be motivated by curiosity or defense. On 14 May 2018,
3657-459: A porbeagle shark was reported to have bitten a fisherman off the coast of Cornwall , United Kingdom , as it was being returned to the sea. At one time, porbeagles were regarded as nuisances by some commercial fishers because they damaged lighter fishing gear intended for smaller species and took hooked fish from lines. This shark is highly valued as a game fish by sport fishers in Ireland ,
3816-581: A propensity for "self-healing and avoiding age-related ailments". A 2007 study from the University of New South Wales in Sydney , Australia , used CT scans of a shark's skull and computer models to measure the shark's maximum bite force. The study reveals the forces and behaviours its skull is adapted to handle and resolves competing theories about its feeding behaviour. In 2008, a team of scientists led by Stephen Wroe conducted an experiment to determine
3975-617: A pup that washed ashore in Australia and died, in another pup in South Africa, and a third six-metre adult male in Indonesia. Great white sharks, like many other sharks, have rows of serrated teeth behind the main ones, ready to replace any that break off. When the shark bites, it shakes its head side-to-side, helping the teeth saw off large chunks of flesh. Great white sharks, like other mackerel sharks, have larger eyes than other shark species in proportion to their body size. The iris of
4134-409: A regular diel migration, spending the day below the thermocline and rising towards the surface at night. The porbeagle has been reported across a temperature range of 1 to 23 °C (34 to 73 °F), with most records between 8 and 20 °C (46 and 68 °F). In a study that included 420 porbeagles caught in the northwest Atlantic off Canada, all were in water below 13 °C (55 °F) and
4293-687: A relatively localized area. In the South Pacific, the population shifts north past 30°S latitude into subtropical waters in winter and spring, and retreats south past 35°S latitude in summer, when sharks are frequently sighted off subantarctic islands. The porbeagle is a very stout-bodied shark with a fusiform (spindle-like) shape. The long, conical snout tapers to a sharp point, and is supported by enlarged, highly calcified rostral cartilages . The eyes are large and black, without nictitating membranes (protective third eyelids). The small, S-shaped nostrils are positioned in front of and below
4452-415: A result, scientists classified the ancient forms under the genus Carcharodon . Although weaknesses in the hypothesis existed, such as uncertainty over exactly which species evolved into the modern great white and multiple gaps in the fossil record, palaeontologists were able to chart the hypothetical lineage back to a 60-million-year-old shark known as Cretalamna as the common ancestor of all sharks within
4611-541: A short band of aerobic "red muscle" along each side, which can contract independently of the regular "white muscle" at a lower energy cost, enhancing the shark's stamina. Porbeagles are among the few fishes that exhibit apparent play behavior. Reports, principally off the Cornish coast, have this species rolling and repeatedly wrapping themselves in long kelp fronds near the surface; this activity may have an exploratory or self-stimulatory purpose, though alternately,
4770-427: A tenth of the weight is made up of the liver, though some yolk also remains in its stomach and continues to sustain the pup until it learns to feed. The overall embryonic growth rate is 7–8 cm (2.8–3.1 in) per month. Sometimes, one pup in a uterus is much smaller than the other, but otherwise normal. These "runts" may result from a dominant, forward-facing embryo eating most of the eggs as they arrive, and/or
4929-469: A variety of interactions. In 2022, research in South Africa suggested that the great white shark has the ability to change colours to camouflage itself depending on the hormones it gives off. Different hormones would change the colour of the skin from white to grey. Skin dosed with adrenaline would turn lighter, with melanocyte-stimulating hormone causing melanocyte cells to dissipate thus making
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5088-415: A whale carcass alongside tiger sharks. In 2020, marine biologists Sasha Dines and Enrico Gennari published a documented incident in the journal Marine and Freshwater Research of a group of great white sharks exhibiting pack-like behaviour, successfully attacking and killing a live juvenile 7 m (23 ft) humpback whale. The sharks utilized the classic attack strategy used on pinnipeds when attacking
5247-650: Is New Zealand's total allowable catch of 249 tons per year, instituted in 2004. In June 2018 the New Zealand Department of Conservation classified the porbeagle as "Not Threatened" with the qualifier "Threatened Overseas" under the New Zealand Threat Classification System . In the eastern North Atlantic, porbeagle fishing has been illegal in waters of the European Union since 2011. From 1985 and until
5406-654: Is a species of mackerel shark in the family Lamnidae , distributed widely in the cold and temperate marine waters of the North Atlantic and Southern Hemisphere . In the North Pacific , its ecological equivalent is the closely related salmon shark ( L. ditropis ). It typically reaches 2.5 m (8.2 ft) in length and a weight of 135 kg (298 lb); North Atlantic sharks grow larger than Southern Hemisphere sharks and differ in coloration and aspects of life history. Gray above and white below,
5565-550: Is an example of gigantothermy . Therefore, the great white shark can be considered an endothermic poikilotherm or mesotherm because its body temperature is not constant but is internally regulated. Great whites also rely on the fat and oils stored within their livers for long-distance migrations across nutrient-poor areas of the oceans. Studies by Stanford University and the Monterey Bay Aquarium published on 17 July 2013 revealed that in addition to controlling
5724-449: Is an opportunistic hunter that preys mainly on bony fishes and cephalopods throughout the water column , including the bottom. Most commonly found over food-rich banks on the outer continental shelf , it makes occasional forays both close to shore and into the open ocean to a depth of 1,360 m (4,460 ft). It also conducts long-distance seasonal migrations , generally shifting between shallower and deeper water. The porbeagle
5883-497: Is arguably the world's largest-known extant macropredatory fish, and is one of the primary predators of marine mammals , such as pinnipeds and dolphins . The great white shark is also known to prey upon a variety of other animals, including fish , other sharks, and seabirds . It has only one recorded natural predator, the orca . The species faces numerous ecological challenges which has resulted in international protection. The International Union for Conservation of Nature lists
6042-411: Is closely related to the prehistoric megalodon . These sharks were considerably larger in size, with megalodon attaining an estimated length of up to 14.2–20.3 m (47–67 ft). Similarities between the teeth of great white and mega-toothed sharks, such as large triangular shapes, serrated blades, and the presence of dental bands, led the primary evidence of a close evolutionary relationship. As
6201-491: Is derived from κάρχαρος ( kárkharos ), which means "jagged" or "sharp". The suffix -odon is a romanization of ὀδών ( odṓn ), a which translates to "tooth". The specific name carcharias is a Latinization of καρχαρίας ( karkharías ), the Ancient Greek word for shark. The great white shark was one of the species originally described by Carl Linnaeus in his 1758 10th edition of Systema Naturae , in which it
6360-442: Is fast and highly active, with physiological adaptations that enable it to maintain a higher body temperature than the surrounding water. It can be solitary or gregarious, and has been known to perform seemingly playful behavior. This shark is aplacental viviparous with oophagy , developing embryos being retained within the mother's uterus and subsisting on non-viable eggs . Females typically bear four pups every year. Only
6519-596: Is found mostly within 30–70°N and 30–50°S latitudes . In the North Atlantic, the northern limit of its range extends from the Newfoundland Grand Banks off Canada , through southern Greenland , to Scandinavia and Russia ; the southern limit of its range extends from New Jersey and Bermuda , through the Azores and Madeira , to Morocco . It is found in the Mediterranean Sea , but not
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6678-612: Is included on the red list of Norway and it has been protected in their national waters since 2012. Any porbeagle caught in EU or Norwegian waters by accident must be released. In the Mediterranean Sea, the porbeagle is on the verge of extinction, with a population decline over 99.99% since the mid-20th century. Its range has contracted to the waters around the Italian Peninsula , where a nursery area may exist. Only
6837-406: Is known as spy-hopping . This behaviour has also been seen in at least one group of blacktip reef sharks , but this might be learned from interaction with humans (it is theorized that the shark may also be able to smell better this way because smell travels through air faster than through water). White sharks are generally very curious animals, display intelligence and may also turn to socializing if
6996-558: Is sold fresh, frozen, or dried and salted, and ranks among the most valuable of any shark: in 1997 and 1998, it had a wholesale price of 5–7 eur/kg, four times that of the blue shark ( Prionace glauca ). Most of the demand comes from Europe, though the United States and Japan also import this species. The fins are shipped to East Asia for use in shark fin soup . The remainder of the shark may also be used for production of leather , liver oil , and fishmeal . International trade in
7155-482: Is subject to debate because some reports are rough estimations or speculations performed under questionable circumstances. Among living cartilaginous fish , only the whale shark ( Rhincodon typus ), the basking shark ( Cetorhinus maximus ) and the giant manta ray ( Manta birostris ), in that order, are on average larger and heavier. These three species are generally quite docile in disposition and given to passively filter-feeding on very small organisms. This makes
7314-470: Is the sole recognized extant species in the genus Carcharodon , and is one of five extant species belonging to the family Lamnidae . Other members of this family include the mako sharks , porbeagle , and salmon shark . The family belongs to the Lamniformes , the order of mackerel sharks. The English name 'white shark' and its Australian variant 'white pointer' is thought to have come from
7473-404: Is typically four, with two embryos oriented in opposing directions sharing each uterus; on rare occasions, a litter may contain as few as one or as many as five pups. The gestation period is 8–9 months. Like other members of its family, the porbeagle is aplacental viviparous with oophagy , i.e. the main source of embryonic nutrition are unfertilized eggs. During the first half of pregnancy,
7632-568: The Guinness Book of World Records , listed two great white sharks as the largest individuals: In the 1870s, a 10.9 m (36 ft) great white captured in southern Australian waters, near Port Fairy , and an 11.3 m (37 ft) shark trapped in a herring weir in New Brunswick , Canada , in the 1930s. However, these measurements were not obtained in a rigorous, scientifically valid manner, and researchers have questioned
7791-548: The Antarctic Peninsula , which date to the middle to late Eocene epoch (50–34 Mya). Much taxonomic confusion remains regarding Lamna in the fossil record due to the high degree of variability in adult tooth morphology within species. The porbeagle has an almost global amphitemperate distribution, i.e., it is absent from the tropics; in the North Pacific, its niche is assumed by the salmon shark. It
7950-818: The Baltic ), and critically endangered in the eastern North Atlantic and Mediterranean Sea. The porbeagle is listed on Annex 1 (Highly Migratory Species) of the UN Convention on the Law of the Sea and on Annex 1 of the Conservation of Migratory Species (CMS; also known as the Bonn Convention ) Migratory Shark Memorandum of Understanding . This species benefits from bans on shark finning instituted by several nations and supranational entities, including Canada,
8109-695: The Black Sea . Normally, North Atlantic sharks only stray as far south as South Carolina and the Gulf of Guinea , but pregnant females from the western North Atlantic population are known to range into the Sargasso Sea , almost as far as Hispaniola , to give birth. In the Southern Hemisphere, the porbeagle apparently occupies a continuous band bound in the south by the Antarctic Convergence , and extending as far north as Chile and Brazil ,
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#17327826821248268-483: The Celtic Sea and on the outer Nova Scotian Shelf , porbeagles congregate at tidally induced thermal fronts to feed on fish that have been drawn by high concentrations of zooplankton . Hunting porbeagles regularly dive from the surface all the way to the bottom, cycling back every few hours; this vertical movement may aid in the detection of olfactory cues. A one-year-old porbeagle 1 m (3.3 ft) long,
8427-565: The Sea of Marmara and Bosphorus . One of the densest-known populations is found around Dyer Island, South Africa . Juvenile great white sharks inhabit a more narrow band of temperatures, between 14 and 24 °C (57 and 75 °F), in shallow coastal nurseries. Increased observation of young sharks in areas they were not previously common, such as Monterey Bay on the Central California coast, suggest climate change may be reducing
8586-497: The Shetland Islands . The male bites at the female's pectoral fins, gill region, and flanks while courting and to hold on for copulation . Two mating grounds are known for western North Atlantic porbeagles, one off Newfoundland and the other on Georges Bank in the Gulf of Maine . Adult females have a single functional ovary , on the right, and two functional uteri. They probably reproduce every year. The litter size
8745-649: The United Kingdom , and the United States . It fights strongly on hook-and-line, but does not usually jump into the air like the related shortfin mako shark . Novice anglers often mistake this shark for the mako, which has earned it the affectionate moniker "fako" in New England . The International Game Fish Association keeps records on the porbeagle. Prized for its meat and fins, the porbeagle has long been under heavy fishing pressure. The meat
8904-606: The Western Cape province of South Africa , Australia to southern Western Australia and southern Queensland , and New Zealand . In New Zealand it is most common south of the Cook Strait. The porbeagle is thought to have colonized the Southern Hemisphere during the Quaternary glaciation (beginning around 2.6 Mya), when the tropical climate zone was much narrower than it is today. Offshore fishing banks are
9063-466: The caudal peduncle are expanded into prominent lateral keels. A second, shorter pair of keels are present below the main keels. The caudal fin is large and crescent-shaped, with the lower lobe almost as long as the upper; both dorsal and ventral depressions (precaudal pits) are at the caudal fin base, and a deep ventral notch is near the tip of the upper caudal fin lobe. The skin is soft and covered by tiny, flattened dermal denticles ( scales ), lending
9222-471: The copepods Dinemoura producta , Laminifera doello-juradoi , and Pandarus floridanus . Natural annual mortality is low, estimated to be 10% for juveniles, 15% for adult males, and 20% for adult females in the western North Atlantic. The porbeagle is an active predator that predominantly ingests small to medium-sized bony fishes . It chases down pelagic fishes such as lancet fish , mackerel , pilchards , herring , and sauries , and forages near
9381-485: The sister species relationship between the porbeagle and the salmon shark ( L. ditropis ), which occurs in place of it in the North Pacific. The genus Lamna evolved 65–45 Mya . When its two extant species diverged from each other is uncertain, though the precipitating event was likely the formation of the ice cap over the Arctic Ocean , which would have isolated sharks in the North Pacific from those in
9540-460: The "lesser white shark". Most scientists prefer 'white shark', as the name "lesser white shark" is no longer used, while some use 'white shark' to refer to all members of the Lamnidae. The scientific genus name Carcharodon literally means "jagged tooth", a reference to the large serrations that appear in the shark's teeth. It is a portmanteau of two Ancient Greek words: the prefix carchar-
9699-534: The 1788 Tableau encyclopédique et methodique des trois règnes de la nature , and based on an earlier 1769 account by Welsh naturalist Thomas Pennant . Bonnaterre named the shark Squalus nasus , the specific epithet nasus being Latin for "nose". In 1816, French naturalist Georges Cuvier placed the porbeagle into its own subgenus, Lamna , which later authors elevated to the rank of full genus. Several phylogenetic studies, based on morphological characters and mitochondrial DNA sequences, have established
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#17327826821249858-510: The Atlantic, but could be as much as 65 years in the South Pacific. Like other members of its family, the porbeagle is endothermic ; metabolic heat generated by its red muscles is conserved within the body by specialized systems of blood vessels called retia mirabilia ( Latin for "wonderful nets"; singular rete mirabile ), that act as highly efficient countercurrent heat exchangers . The porbeagle has several rete mirabile systems:
10017-546: The Conservation of European Wildlife and Natural Habitats). However, these listings have yet to result in the implementation of new management plans, despite the recognized need for urgent action. The European Union prohibits EU vessels from fishing for, retaining, boarding, transhipping, or landing porbeagle sharks in all waters since January 2011. It is subject to a zero total allowable catch in EU waters by any vessel. The western North Atlantic porbeagle population has
10176-603: The EU ban, the Faroe Islands and Norway (which are not members of the EU) were allowed annual quotas of 200 tons and 125 tons, respectively, from European Community waters. Although these quotas were lower than the originals set in 1982 (500 tons for Norway and 300 tons for the Faroe Islands), they were still consistently higher than the yearly total porbeagle catch in the region, thus had no practical effect. The species
10335-523: The English "beagle". The Dictionary also notes that no evidence exists for a connection to the French porc , meaning "swine", or to porpoise , as has been proposed. Other common names for the porbeagle include Atlantic mackerel shark, Beaumaris shark, bottle-nosed shark, and blue dog. The first scientific description of the porbeagle was authored by French naturalist Pierre Joseph Bonnaterre in
10494-657: The KANGA specimen was 5.8–6.4 m (19–21 ft) long. In a similar fashion, I. K. Fergusson also used shark size estimation methods proposed by J. E. Randall to suggest that the MALTA specimen was 5.3–5.7 m (17–19 ft) long. However, photographic evidence suggested that these specimens were larger than the size estimations yielded through Randall's methods. Thus, a team of scientists—H. F. Mollet, G. M. Cailliet, A. P. Klimley, D. A. Ebert, A. D. Testi, and L. J. V. Compagno —reviewed
10653-399: The Lamnidae. However, it is now understood that the great white shark holds closer ties to the mako sharks and is descended from a separate lineage as a chronospecies unrelated to the mega-toothed sharks. This was proven with the discovery of a transitional species that connected the great white to an unserrated shark known as Carcharodon hastalis . This transitional species, which
10812-430: The North Atlantic is often cited as archetypal of the "boom and bust" pattern of most shark fisheries. Factors including a small litter size, long maturation time, and the capture of multiple age classes all contribute to this shark's susceptibility to overfishing . The International Union for Conservation of Nature has assessed the porbeagle globally as vulnerable , endangered in the western North Atlantic (including
10971-679: The North Atlantic. Fossilized porbeagle remains are known from Late Miocene epoch (about 7.2 Mya) deposits in Belgium and the Netherlands, Pliocene epoch (5.3–2.6 Mya) deposits in Belgium, Spain , and Chile , and Pleistocene epoch (2.6 Mya to 12,000 BP) deposits in the Netherlands. However, Lamna teeth that closely resemble those of the porbeagle have been found in the La Meseta Formation on Seymour Island off
11130-594: The Northeast Atlantic, in the 1960s, the Norwegian fishing fleet moved west to the waters off New England and Newfoundland. A few years later, they were joined by longline vessels from the Faroe Islands . Norwegian annual catches rose from 1,900 tons in 1961 to over 9,000 tons in 1965; the catch was largely exported to Italy , where porbeagle ( smeriglio ) is an extremely popular food fish. Again,
11289-579: The Port Fairy shark was of the order of 5 m (16 ft) in length and suggested that a mistake had been made in the original record, in 1870, of the shark's length". While these measurements have not been confirmed, some great white sharks caught in modern times have been estimated to be more than 7 m (23 ft) long, but these claims have received some criticism. However, J. E. Randall believed that great white shark may have exceeded 6.1 m (20 ft) in length. A great white shark
11448-635: The Sargasso Sea for pupping, keeping deeper than 600 m (2,000 ft) during the day and 200 m (660 ft) at night so as to stay in the cooler waters beneath the Gulf Stream . In the eastern North Atlantic, porbeagles are believed to spend spring and summer in shallow continental shelf waters, and disperse northwards to overwinter in deeper waters offshore. Migrating sharks may travel upwards of 2,300 km (1,400 mi), though once they reach their destination they tend to remain within
11607-532: The South African coast led by biologists from the University of Miami in 2012 indicates that despite high levels of mercury, lead, and arsenic, there was no sign of raised white blood cell count and granulate to lymphocyte ratios, indicating the sharks had healthy immune systems. This discovery suggests a previously unknown physiological defence against heavy metal poisoning. Great whites are known to have
11766-536: The Southern Hemisphere, as well. This species segregates by size and sex in the North Atlantic, and at least by size in the South Pacific. For example, males outnumber females 2:1 off Spain , females are 30% more numerous than males off Scotland , and immature males are predominant in the Bristol Channel . Older, larger sharks may frequent higher latitudes than younger individuals. Seasonal migrations have been observed in porbeagles from both hemispheres. In
11925-693: The United States, Brazil, Australia , the European Union, and the International Commission for the Conservation of Atlantic Tunas . Although the Animals Committee of the UN Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) recommended additional conservation actions for the porbeagle, CITES rejected proposals to list the species in 2008 and again in 2010. In March 2013,
12084-519: The Uruguayan tuna pelagic longline fishery peaked in 1984 with 150 tons landed. Records of catch per unit effort for this fishery have shown a 90% decline in porbeagle landings from 1988 to 1998, though whether this reflects a real population decline or changing fishing habits is uncertain. New Zealand has reported annual catches of 150–300 tons, mostly of immature individuals, from 1998 to 2003. The rapid collapse of porbeagle stocks on both sides of
12243-720: The area feed on smaller fish species until they are large enough to prey on marine mammals such as seals. White sharks also attack dolphins and porpoises from above, behind or below to avoid being detected by their echolocation . Targeted species include dusky dolphins ( Sagmatias obscurus ), Risso's dolphins ( Grampus griseus ), bottlenose dolphins ( Tursiops ssp.), humpback dolphins ( Sousa ssp.), harbour porpoises ( Phocoena phocoena ), and Dall's porpoises ( Phocoenoides dalli ). Groups of dolphins have occasionally been observed defending themselves from sharks with mobbing behaviour. White shark predation on other species of small cetacean has also been observed. In August 1989,
12402-705: The bottom for groundfishes such as cusk , haddock , redfish (i.e., Sebastes , Lutjanus , Trachichthyidae , and Berycidae ), cod , hake , icefish , dories , sand lances , lumpsuckers , and flatfish . Cephalopods , particularly squid , also form an important component of its diet, while smaller sharks such as spiny dogfish ( Squalus acanthias ) and tope sharks ( Galeorhinus galeus ) are rarely taken. Examinations of porbeagle stomach contents have also found small shelled molluscs , crustaceans , echinoderms , and other invertebrates , which were likely ingested incidentally, as well as inedible debris such as small stones, feathers , and garbage fragments. In
12561-403: The carapace around a flipper, immobilizing the turtle. The heaviest species of bony fish, the oceanic sunfish ( Mola mola ), has been found in great white shark stomachs. Whale carcasses comprise an important part of the diet of white sharks. However, this has rarely been observed due to whales dying in remote areas. It has been estimated that 30 kg (66 lb) of whale blubber could feed
12720-492: The carcass discarded. Intensive fishing for the porbeagle dates back the 1930s, when Norway and to a lesser extent Denmark began operating longline vessels in the Northeast Atlantic. The Norwegian annual catch rose from 279 tons in 1926 to 3,884 tons in 1933, and peaked at around 6,000 tons in 1947, with the resumption of fishing after World War II . Soon after, the stock collapsed; Norwegian annual catches declined steadily to 1,200–1,900 tons from 1953 to 1960, 160–300 tons in
12879-482: The carcass eating chunks that drifted away. Unusually for the area, large numbers of sharks over five metres long were observed, suggesting that the largest sharks change their behaviour to search for whales as they lose the manoeuvrability required to hunt seals. The investigating team concluded that the importance of whale carcasses, particularly for the largest white sharks, has been underestimated. In another documented incident, white sharks were observed scavenging on
13038-535: The cases of the KANGA and MALTA specimens in 1996 to resolve the dispute by conducting a comprehensive morphometric analysis of the remains of these sharks and re-examination of photographic evidence in an attempt to validate the original size estimations and their findings were consistent with them. The findings indicated that estimations by P. Resiley and J. Abela are reasonable and could not be ruled out. A particularly large female great white nicknamed "Deep Blue", estimated measuring at 6.1 m (20 ft)
13197-435: The caudal fin in its depressed position, and is estimated to have weighed 2,000 kg (4,410 lb). According to J. E. Randall, the largest white shark reliably measured was a 5.94 m (19.5 ft) specimen reported from Ledge Point, Western Australia in 1987, but it is unclear whether that length was measured with the caudal fin in its depressed or natural position. Another great white specimen of similar size
13356-415: The closest living relative of the great white to be the mako sharks of the genus Isurus , which diverged some time between 60 and 43 million years ago. Tracing this evolutionary relationship through fossil evidence, however, remains subject to further paleontological study. The original hypothesis of the great white shark's origin held that it is a descendant of a lineage of mega-toothed sharks , and
13515-664: The coast of Cuba was at the time considered reliable by some experts. However, later studies revealed this particular specimen to be around 4.9 m (16 ft) in length, i.e. a specimen within the typical maximum size range. The largest great white recognized by the International Game Fish Association (IGFA) is one caught by Alf Dean in southern Australian waters in 1959, weighing 1,208 kg (2,663 lb). A number of very large unconfirmed great white shark specimens have been recorded. For decades, many ichthyological works, as well as
13674-518: The early 1970s, and 10–40 tons in the late 1980s to early 1990s. Similarly, Danish annual catches fell from 1,500 tons in the early 1950s to under 100 tons in the 1990s. France and Spain began to target porbeagles in the Northeast Atlantic in the 1970s. French fishers operate mainly in the Celtic Sea and the Bay of Biscay , and saw a decline from an annual catch over 1,000 tons in 1979 to 300–400 tons in
13833-463: The eastern North Atlantic in the 1950s, and the western North Atlantic in the 1960s. The porbeagle continues to be caught throughout its range, both intentionally and as bycatch , with varying degrees of monitoring and management. The International Union for Conservation of Nature (IUCN) has assessed the porbeagle as vulnerable worldwide, and as either endangered or critically endangered in different parts of its northern range. The etymology of
13992-410: The embryo appears pink because it lacks pigment except in its eyes, and its head and gill regions are laterally enlarged and gelatinous. The yolk stomach can comprise up to 81% of the embryo's total weight when it is 30–42 cm (12–17 in) long. The embryo gains pigment and sheds its fangs at a length of 34–38 cm (13–15 in). Around this time, the mother stops producing ova. From then on,
14151-439: The embryo relies mainly on the yolk stored in its stomach, though it may continue to feed on remaining eggs by squishing the capsules between its jaws or swallowing them whole. It begins to transfer its energy stores from its stomach to its liver, causing the former to shrink and the latter to grow exponentially. The embryo is essentially fully pigmented by a length of 40 cm (16 in), and has assumed its newborn appearance by
14310-664: The eye is a deep blue instead of black. In great white sharks, sexual dimorphism is present, and females are generally larger than males. Male great whites on average measure 3.4 to 4.0 m (11 to 13 ft) in length, while females measure 4.6 to 4.9 m (15 to 16 ft). Adults of this species weigh 522–771 kg (1,151–1,700 lb) on average; however, mature females can have an average mass of 680–1,110 kg (1,500–2,450 lb). The largest females have been verified up to 6.1 m (20 ft) in length and an estimated 1,905 kg (4,200 lb) in weight, perhaps up to 2,268 kg (5,000 lb). The maximum size
14469-596: The favored habitat of the porbeagle, though it can be found from a depth of 1,360 m (4,460 ft) in oceanic basins to littoral (close to shore) waters less than 1 m (3.3 ft) deep, over the entire water column . A single, anomalous record was made of a juvenile in brackish water in Mar Chiquita in Argentina . A tracking study off the British Isles has found substantial variation in
14628-559: The forces required to attack larger prey such as pinnipeds and cetaceans until they reach a length of 3 m (9.8 ft) or more, at which point their jaw cartilage mineralizes enough to withstand the impact of biting into larger prey species. Upon approaching a length of nearly 4 m (13 ft), great white sharks begin to target predominantly marine mammals for food, though individual sharks seem to specialize in different types of prey depending on their preferences. They seem to be highly opportunistic. These sharks prefer prey with
14787-431: The four encounters with the giant shark he participated in with great detail in his book Great White Sharks On Their Best Behavior . One contender in maximum size among the predatory sharks is the tiger shark ( Galeocerdo cuvier ). While tiger sharks, which are typically both a few feet smaller and have a leaner, less heavy body structure than white sharks, have been confirmed to reach at least 5.5 m (18 ft) in
14946-559: The great white and C. hastalis were known worldwide, C. hubbelli is primarily found in California , Peru , Chile , and surrounding coastal deposits, indicating that the great white had Pacific origins. C. hastalis continued to thrive alongside the great white until its last appearance around one million years ago and is believed to have possibly sired a number of additional species, including Carcharodon subserratus and Carcharodon plicatilis . However, Yun argued that
15105-554: The great white is a coastal species. According to a recent study, California great whites have migrated to an area between Baja California Peninsula and Hawaii known as the White Shark Café to spend at least 100 days before migrating back to Baja. On the journey out, they swim slowly and dive down to around 900 m (3,000 ft). After they arrive, they change behaviour and do short dives to about 300 m (980 ft) for up to ten minutes. Another white shark that
15264-473: The great white shark as a vulnerable species , and it is included in Appendix II of CITES . It is also protected by several national governments, such as Australia (as of 2018). Due to their need to travel long distances for seasonal migration and extremely demanding diet, it is not logistically feasible to keep great white sharks in captivity; because of this, while attempts have been made to do so in
15423-526: The great white shark the largest extant macropredatory fish. Great white sharks measure approximately 1.2 m (3.9 ft) when born, and grow about 25 cm (9.8 in) every year. A complete female great white shark specimen in the Museum of Zoology in Lausanne, and claimed by De Maddalena et al. (2003) as the largest preserved specimen, measured 5.83 m (19.1 ft) in total body length with
15582-788: The great white shark's jaw power and findings indicated that a specimen massing 3,324 kg (7,328 lb) could exert a bite force of 18,216 newtons (4,095 lbf ). This shark's behaviour and social structure are complex. In South Africa, white sharks have a dominance hierarchy where an individual's rank is primarily established by their size, and to a lesser extent, their sex and "squatter's rights"; larger sharks dominate smaller sharks , females dominate males , and established residents dominate newcomers . When hunting, great whites tend to separate and resolve conflicts with rituals and displays. White sharks rarely resort to combat, although some individuals have been found with bite marks that match those of other white sharks. This suggests that when
15741-526: The highest core temperatures within its family, 8–10 °C (14–18 °F) warmer than that of the surrounding water. Being warm-bodied may allow this shark to maintain higher cruising speeds, hunt in deep water for extended periods of time, and/or enter higher latitudes during winter to exploit food resources not available to other sharks. The orbital retia of the porbeagle can raise the temperature of its brain and eyes by 3–6 °C (5.4–10.8 °F), and likely serve to buffer those sensitive organs against
15900-548: The increase in seal populations on Cape Cod , Massachusetts since the enactment of the Marine Mammal Protection Act in 1972. Currently very little is known about the hunting and movement patterns of great whites off Cape Cod, but ongoing studies hope to offer insight into this growing shark population. The Massachusetts Division of Marine Fisheries (part of the Department of Fish and Game ) began
16059-497: The large temperature shifts that accompany changes in depth; potential benefits of this include increased visual acuity and reduced response times . The porbeagle has very rarely, if ever, bitten swimmers or boats. As of 2009, the International Shark Attack File attributes three bites to this species, one provoked and none fatal, and two on boats. One older anecdote tells of a fisherman who provoked
16218-610: The late 1990s. Catches by Spanish fishers were highly variable, ranging from negligible to over 4,000 tons per year, which may reflect shifts of fishing effort into historically less-exploited waters. Since 2011, all fishing for the porbeagle has been illegal in waters of the European Union , and EU-registered vessels are also prohibited from fishing for the species in international waters . In 2012, similar restriction came into effect in Norway. As porbeagles had become scarce in
16377-562: The length, an unverified specimen was reported to have measured 7.4 m (24 ft) in length and weighed 3,110 kg (6,860 lb), more than two times heavier than the largest confirmed specimen at 1,524 kg (3,360 lb). Some other macropredatory sharks such as the Greenland shark ( Somniosus microcephalus ) and the Pacific sleeper shark ( S. pacificus ) are also reported to rival these sharks in length (but probably weigh
16536-407: The level of the eyes. The mouth is large and strongly curved, with moderately protrusible jaws. North Atlantic sharks have 28–29 upper tooth rows and 26–27 lower tooth rows, while Southern Hemisphere sharks have 30–31 upper tooth rows and 27–29 lower tooth rows. Each tooth has a strongly arched base and a nearly straight, awl-like central cusp, which is flanked by a pair of smaller cusplets in all but
16695-432: The location of the remains of animals that can be scavenged. As biologging can help to reveal social habits, it allows a better understanding to be made in future studies regarding the full extent of social interactions in large marine animals, including the great white shark. The great white shark is one of only a few sharks known to regularly lift its head above the sea surface to gaze at other objects such as prey. This
16854-455: The major oceans. It is the only known surviving species of its genus Carcharodon . The great white shark is notable for its size, with the largest preserved female specimen measuring 5.83 m (19.1 ft) in length and around 2,000 kg (4,400 lb) in weight at maturity. However, most are smaller; males measure 3.4 to 4.0 m (11 to 13 ft), and females measure 4.6 to 4.9 m (15 to 16 ft) on average. According to
17013-456: The majority between 5 and 10 °C (41 and 50 °F). Porbeagle populations in the Northern and Southern Hemispheres appear to be completely separate. Two stocks are in the North Atlantic, east and west, that seldom mix; only one individual is known to have crossed the Atlantic, covering 4,260 km (2,650 mi) from Ireland to Canada . Several discrete stocks are likely present in
17172-464: The means to open egg capsules. At a length of 10–12 cm (3.9–4.7 in), the embryo grows two massive, recurved "fangs" in the lower jaw for tearing open capsules, as well as two much smaller teeth in the upper jaw. It begins to feed voraciously on yolk, acquiring an enormously distended stomach; to accommodate this, the muscles on the belly split down the middle and the skin on the abdomen stretches greatly. At 20–21 cm (7.9–8.3 in) long,
17331-573: The most frequently eaten at elephant seal colonies. Prey is normally attacked sub-surface. Harbor seals ( Phoca vitulina ) are taken from the surface and dragged down until they stop struggling. They are then eaten near the bottom. California sea lions ( Zalophus californianus ) are ambushed from below and struck mid-body before being dragged and eaten. In the Northwest Atlantic mature great whites are known to feed on both harbor and grey seals. Unlike adults, juvenile white sharks in
17490-508: The mother ovulates enormous numbers of tiny ova , packed into capsules up to 7.5 cm (3.0 in) long, into her uteri. A newly conceived embryo is sustained by a yolk sac and emerges from its egg capsule at 3.2–4.2 cm (1.3–1.7 in) long. At this time, the embryo has well-developed external gills and a spiral valve intestine . When the embryo is 4.2–9.2 cm (1.7–3.6 in) long, it has resorbed its external gills and most of its yolk sac, but cannot yet feed, as it lacks
17649-465: The mother being unable to provide an adequate egg supply for all her offspring. Birthing occurs from April to September, peaking in April and May (spring-summer) for North Atlantic sharks and June and July (winter) for Southern Hemisphere sharks. In the western North Atlantic, birth occurs well offshore in the Sargasso Sea at depths around 500 m (1,600 ft). Both sexes grow at similar rates until
17808-448: The onset of maturation, with females maturing later and at a larger size than males. In the first four years of life, the annual growth rate is 16–20 cm (6.3–7.9 in) and similar in both hemispheres; thereafter, sharks from the western South Pacific begin to grow slower than those from the North Atlantic. In the North Atlantic, males mature at a fork length of 1.6–1.8 m (5.2–5.9 ft) and an age of 6–11 years, and females at
17967-471: The orbital retia accessing its brain and eyes, the lateral cutaneous retia accessing its swimming muscles, the suprahepatic rete accessing its viscera , and the kidney rete . Among sharks, the porbeagle's capacity for elevating body temperature is second only to the salmon shark's. Its red muscles are located deep within the body, adjacent to the spine , and its lateral rete is composed of over 4,000 small arteries arranged in bands. It has one of
18126-567: The past, there are no known aquariums in the world believed to house a live specimen. The great white shark is depicted in popular culture as a ferocious man-eater , largely as a result of the novel Jaws by Peter Benchley and its subsequent film adaptation by Steven Spielberg . Humans are not a preferred prey, but nevertheless it is responsible for the largest number of reported and identified fatal unprovoked shark attacks on humans. However, attacks are rare, typically occurring fewer than 10 times per year globally. The great white
18285-436: The porbeagle appears to be significant, but remains unquantified, as shark products tend not to be reported to the species level, and many consist of a mix of various species. This shark is caught most readily on longlines , but is also susceptible to gillnets , driftnets , trawls , and handlines. It is valuable enough to be generally retained when caught as bycatch ; if storage space cannot be spared, it may be finned and
18444-448: The porbeagle has a very stout midsection that tapers towards the long, pointed snout and the narrow base of the tail . It has large pectoral and first dorsal fins , tiny pelvic , second dorsal, and anal fins , and a crescent-shaped caudal fin . The most distinctive features of this species are its three-cusped teeth, the white blotch at the aft base of its first dorsal fin, and the two pairs of lateral keels on its tail. The porbeagle
18603-490: The porbeagle was listed on Appendix II of CITES, allowing for increased regulation in the international trade of this species. In March 2015, The National Marine Fisheries Service (NMFS) responded to a court order to compile information as to whether the shark will be listed as threatened or endangered under the Endangered Species Act . The only regulation of porbeagle catches in the Southern Hemisphere
18762-417: The porbeagle. In one record, a small individual caught off Argentina bore bite marks from a copper shark ( Carcharhinus brachyurus ) or similar species, but whether the porbeagle was the target of attempted predation or if the two were simply involved in interspecific aggression is uncertain. Known parasites of this species include the tapeworms Dinobothrium septaria and Hepatoxylon trichiuri , and
18921-504: The possibility of interaction between shark populations that were previously thought to have been discrete. The reasons for their migration and what they do at their destination is still unknown. Possibilities include seasonal feeding or mating. In the Northwest Atlantic, the white shark populations off the New England coast were nearly eradicated due to over-fishing. In recent years, the populations have grown greatly, largely due to
19080-473: The prey species. They immobilize northern elephant seals ( Mirounga angustirostris ) with a large bite to the hindquarters (which is the main source of the seal's mobility) and wait for the seal to bleed to death. This technique is especially used on adult male elephant seals, which are typically larger than the shark, ranging between 1,500 and 2,000 kg (3,300 and 4,400 lb), and are potentially dangerous adversaries. However, juvenile elephant seals are
19239-415: The primary fisher of porbeagles in the region. Between 1994 and 1998, Canadian fishing vessels landed 1,000–2,000 tons per year, which depleted the population to 11–17% of pre-exploitation levels by 2000. Strict regulations and greatly reduced fishing quotas introduced in 2000 have since begun to reverse the stock decline, though recovery of the stock is projected to take decades due to the low productivity of
19398-423: The range of juvenile great white sharks and shifting it toward the poles. The great white is an epipelagic fish, observed mostly in the presence of rich game, such as fur seals ( Arctocephalus ssp.), sea lions , cetaceans , other sharks, and large bony fish species. In the open ocean, it has been recorded at depths as great as 1,200 m (3,900 ft). These findings challenge the traditional notion that
19557-419: The reliability of these measurements for a long time, noting they were much larger than any other accurately reported sighting. Later studies proved these doubts to be well-founded. This New Brunswick shark may have been a misidentified basking shark , as the two have similar body shapes. The question of the Port Fairy shark was settled in the 1970s when J. E. Randall examined the shark's jaws and "found that
19716-486: The rise of two separate descendants, the one representing the great white shark lineage being Macrorhizodus praecursor . Great white sharks live in almost all coastal and offshore waters which have water temperature between 12 and 24 °C (54 and 75 °F), with greater concentrations in the United States ( Northeast and California ), South Africa, Japan, Oceania , Chile, and the Mediterranean including
19875-631: The shark successfully killed the whale. Johnson suggested that the shark may have strategized its attack in order to kill such a large animal. Stomach contents of great whites also indicates that whale sharks both juvenile and adult may also be included on the animal's menu, though whether this is active hunting or scavenging is not known at present. Great white sharks were previously thought to reach sexual maturity at around 15 years of age, but are now believed to take far longer; male great white sharks reach sexual maturity at age 26, while females take 33 years to reach sexual maturity. Maximum life span
20034-484: The shark to locate even immobile animals by detecting their heartbeat. Most fish have a less-developed but similar sense using their body's lateral line . To more successfully hunt fast and agile prey such as sea lions, the great white has adapted to maintain a body temperature warmer than the surrounding water. One of these adaptations is a " rete mirabile " (Latin for "wonderful net"). This close web-like structure of veins and arteries, located along each lateral side of
20193-843: The shark's skin a darker colour, although hormone mediated color change is not fully validated due to the limited number of test subjects ( i.e. great whites). The camo shark hypothesis is supported by the fact that zebra sharks can change their colour as they age, and rainbow sharks can lose colour due to stress and ageing. Great white sharks are generalist carnivores , preying upon fish (e.g. tuna , rays , other sharks ), cetaceans (i.e., dolphins , porpoises , whales ), pinnipeds (e.g. seals , fur seals , and sea lions ), squid , sea turtles , sea otters ( Enhydra lutris ) and seabirds . Great whites have also been known to eat objects that they are unable to digest. Juvenile white sharks predominantly prey on fish, including other elasmobranchs , as their jaws are not strong enough to withstand
20352-401: The shark's stark white underside, a characteristic feature most noticeable in beached sharks lying upside down with their bellies exposed. Colloquial use favours the name 'great white shark', with 'great' perhaps stressing the size and prowess of the species, and "white shark" having historically been used to describe the much smaller oceanic white-tipped shark , later referred to for a time as
20511-479: The shark, conserves heat by warming the cooler arterial blood with the venous blood that has been warmed by the working muscles. This keeps certain parts of the body (particularly the stomach) at temperatures up to 14 °C (25 °F) above that of the surrounding water, while the heart and gills remain at sea temperature. When conserving energy, the core body temperature can drop to match the surroundings. A great white shark's success in raising its core temperature
20670-521: The sharks appeared to become lethargic, no longer swimming to the surface; they were observed mouthing the carcass but apparently unable to bite hard enough to remove flesh, they would instead bounce off and slowly sink. Up to eight sharks were observed feeding simultaneously, bumping into each other without showing any signs of aggression; on one occasion a shark accidentally bit the head of a neighbouring shark, leaving two teeth embedded, but both continued to feed unperturbed. Smaller individuals hovered around
20829-531: The sharks may be attempting to feed on small kelp organisms or scrape off parasites. In addition, porbeagles within a group have been seen chasing each other, and they will reportedly "play with anything floating on the water"; individuals have been observed prodding, tossing, or biting natural and artificial objects, including pieces of driftwood and balloon floats used by anglers. Great white sharks ( Carcharodon carcharias ) and killer whales ( Orcinus orca ) are plausible, albeit undocumented, predators of
20988-420: The sharks' buoyancy, the liver of great whites is essential in migration patterns. Sharks that sink faster during drift dives were revealed to use up their internal stores of energy quicker than those which sink in a dive at more leisurely rates. Toxicity from heavy metals seems to have little negative effects on great white sharks. Blood samples taken from forty-three individuals of varying size, age and sex off
21147-408: The short-term movements of this species, both between and within individuals. Vertical movements tended to increase with water depth and corresponding temperature stratification ; in shallow, unstratified waters, sharks either showed no pattern in changing depth or made reverse diel movements , spending the day in shallow water and descending at night. In deeper, stratified waters, the sharks performed
21306-519: The situation demands it. At Seal Island , white sharks have been observed arriving and departing in stable "clans" of two to six individuals on a yearly basis. Whether clan members are related is unknown, but they get along peacefully enough. In fact, the social structure of a clan is probably most aptly compared to that of a wolf pack, in that each member has a clearly established rank and each clan has an alpha leader. When members of different clans meet, they establish social rank nonviolently through any of
21465-479: The smallest individuals. The five pairs of gill slits are long and precede the pectoral fin bases. The pectoral fins are long and narrow. The first dorsal fin is large and high, with a rounded apex, and originating just behind the pectoral fin bases. The pelvic fins are much smaller than the first dorsal fin. The second dorsal and anal fins are smaller still, and placed about even with each other on narrow bases that allow pivoting from side to side. The sides of
21624-527: The species under its Species At Risk Act, but further reduced the total fishing quota to 185 tons. In US waters, the 1993 Fishery Management Plan for Sharks of the Atlantic Ocean sets an annual quota of 92 tons (after processing) for the porbeagle. In 2006, this species was listed as a species of concern by the NMFS, meaning that it merits conservation concern, but data are insufficient for inclusion on
21783-645: The species. Some evidence shows that incidental artificial selection caused by heavy fishing has led to a compensatory growth response, i.e. faster growth and earlier maturation. In the Southern Hemisphere, commercial fishing for the porbeagle is mostly undocumented. Substantial numbers are caught incidentally by pelagic longline fisheries targeting more valuable species such as southern bluefin tuna ( Thunnus maccoyii ), swordfish ( Xiphias gladius ), and Patagonian toothfish ( Dissostichus eleginoides ), including vessels operated by Japan , Uruguay , Argentina , South Africa , and New Zealand . Porbeagle catches by
21942-417: The stock collapsed, this time in only six years; by 1970, Norwegian catches had fallen under 1,000 tons per year, and Faroese catches observed a similar trend. With the population decimated, most fishers moved on or switched to other species. Porbeagle numbers gradually recovered in the ensuing 25 years, to about 30% of pre-exploitation levels. In 1995, Canada established an Exclusive Economic Zone and became
22101-490: The surface of the water. The peak burst speed is estimated to be above 40 km/h (25 mph). They have also been observed chasing prey after a missed attack. Prey is usually attacked at the surface. Shark attacks occur most often in the morning, within two hours of sunrise, when visibility is poor. Their success rate is 55% in the first two hours, falling to 40% in late morning after which hunting stops. Off California, sharks use different predation techniques depending on
22260-406: The thickest-bodied members of their family (length-depth ratio approaching 4.5), and consequently have the stiffest swimming style; they oscillate their tails while holding their bodies mostly rigid, which confers propulsive power with high energy efficiency, but at the cost of maneuverability. The large gill surface area of the porbeagle allows more oxygen to be delivered to its tissues. It also has
22419-424: The tooth fossil remains of C. hastalis and Great White Shark "have been documented from the same deposits, hence the former cannot be a chronospecific ancestor of the latter." He also criticized that the C. hastalis "morphotype has never been tested through phylogenetic analyses," and denoted that as of 2021, the argument that the modern Carcharodon lineage with narrow, serrated teeth evolved from C. hastalis with
22578-661: The two sexes are similar in size, with males and females attaining fork lengths of 2.0 and 2.1 m (6.6 and 6.9 ft) respectively. Most porbeagles weigh no more than 135 kg (298 lb), with the record being a 230 kg (510 lb) individual caught off Caithness , Scotland , in 1993. Fast and energetic, the porbeagle can be found singly or in groups. Its fusiform body, narrow caudal peduncle with lateral keels, and crescent-shaped tail are adaptations for efficiently sustaining speed, which have also been independently evolved by tunas , billfishes , and several other groups of active fishes. The salmon shark and it are
22737-412: The warm-water eddies, spending the daytime hours at depths of 450 m (1,480 ft) and coming to the surface at night. The great white shark has a robust, large, conical snout. The upper and lower lobes on the tail fin are approximately the same size which is similar to some mackerel sharks . A great white displays countershading , by having a white underside and a grey dorsal area (sometimes in
22896-542: The western North Atlantic, much of the population spends the spring in the deep waters of the Nova Scotia continental shelf , and migrates north a distance of 500–1,000 km (310–620 mi) to spend late summer and fall in the shallow waters of the Newfoundland Grand Banks and the Gulf of St. Lawrence . In December, large, mature females migrate south over 2,000 km (1,200 mi) into
23055-414: The western North Atlantic, porbeagles feed mainly on pelagic fishes and squid in spring, and on groundfishes in the fall; this pattern corresponds to the spring-fall migration of these sharks from deeper to shallower waters, and the most available prey types in those respective habitats. Therefore, the porbeagle seems to be an opportunistic predator without strong diet specificity. During spring and summer in
23214-425: The whale, even utilizing the bite-and-spit tactic they employ on smaller prey items. The whale was an entangled individual, heavily emaciated and thus more vulnerable to the sharks' attacks. The incident is the first known documentation of great whites actively killing a large baleen whale. A second incident regarding great white sharks killing humpback whales involving a single large female great white nicknamed Helen
23373-409: The word "porbeagle" is obscure. A common suggestion is that it combines " porpoise " and " beagle ", referencing this shark's shape and tenacious hunting habits. Another is that it is derived from the Cornish porth , meaning " harbor ", and bugel , meaning " shepherd ". The Oxford English Dictionary states that the word was either borrowed from Cornish or formed from a Cornish first element with
23532-528: Was Lamia , first coined by Guillaume Rondelet in his 1554 book Libri de Piscibus Marinis , who also identified it as the fish that swallowed the prophet Jonah in biblical texts. Linnaeus recognized both names as previous classifications. Carcharias taurus [REDACTED] Cetorhinus maximus Lamna nasus Lamna ditropis Carcharodon carcharias [REDACTED] Isurus oxyrinchus [REDACTED] Isurus paucus Molecular clock studies published between 1988 and 2002 determined
23691-581: Was a female caught in August 1988 in the Gulf of St. Lawrence , off Prince Edward Island, by David McKendrick of Alberton , Prince Edward Island . This female great white was 6.1 m (20 ft) long, as verified by the Canadian Shark Research Center. A report of a specimen reportedly measuring 6.4 m (21 ft) in length and with a body mass estimated at 3,175–3,324 kg (7,000–7,328 lb) caught in 1945 off
23850-632: Was captured near Kangaroo Island in Australia on 1 April 1987. This shark was estimated to be more than 6.9 m (23 ft) long by Peter Resiley, and has been designated as KANGA. Another great white shark was caught in Malta by Alfredo Cutajar on 16 April 1987. This shark was also estimated to be around 7.13 m (23.4 ft) long by John Abela and has been designated as MALTA. However, Cappo drew criticism because he used shark size estimation methods proposed by J. E. Randall to suggest that
24009-412: Was documented off the coast of South Africa. Working alone, the shark attacked a 33 ft (10 m) emaciated and entangled humpback whale by attacking the whale's tail to cripple it before she managed to drown the whale by biting onto its head and pulling it underwater. The attack was witnessed via aerial drone by marine biologist Ryan Johnson , who said the attack went on for roughly 50 minutes before
24168-454: Was filmed off Guadalupe during shooting for the 2014 episode of Shark Week "Jaws Strikes Back". Deep Blue would also later gain significant attention when she was filmed interacting with researcher Mauricio Hoyas Pallida in a viral video that Mauricio posted on Facebook on 11 June 2015. Deep Blue was later seen off Oahu in January 2019 while scavenging a sperm whale carcass, whereupon she
24327-400: Was filmed swimming beside divers including dive tourism operator and model Ocean Ramsey in open water. A particularly infamous great white shark, supposedly of record proportions, once patrolled the area that comprises False Bay , South Africa, was said to be well over 7 m (23 ft) during the early 1980s. This shark, known locally as the "Submarine", had a legendary reputation that
24486-462: Was identified as an amphibian and assigned the scientific name Squalus carcharias , Squalus being the genus that he placed all sharks in. By the 1810s, it was recognized that the shark should be placed in a new genus, but it was not until 1838 when Sir Andrew Smith coined the name Carcharodon as the new genus. There have been a few attempts to describe and classify the great white before Linnaeus. One of its earliest mentions in literature as
24645-427: Was named Carcharodon hubbelli in 2012, demonstrated a mosaic of evolutionary transitions between the great white and C. hastalis , namely the gradual appearance of serrations, in a span of between 8 and 5 million years ago. The progression of C. hubbelli characterized shifting diets and niches; by 6.5 million years ago, the serrations were developed enough for C. hubbelli to handle marine mammals. Although both
24804-1069: Was originally believed to be more than 30 years, but a study by the Woods Hole Oceanographic Institution placed it at upwards of 70 years. Examinations of vertebral growth ring count gave a maximum male age of 73 years and a maximum female age of 40 years for the specimens studied. The shark's late sexual maturity, low reproductive rate, long gestation period of 11 months and slow growth make it vulnerable to pressures such as overfishing and environmental change. Porbeagle Lamna philippii Perez Canto, 1886 Lamna punctata Storer, 1839 Lamna whitleyi Phillipps, 1935 Oxyrhina daekayi Gill, 1861 Selanonius walkeri Fleming, 1828 Squalus cornubicus Gmelin, 1789 Squalus cornubiensis Pennant, 1812 Squalus monensis Shaw, 1804 Squalus nasus Bonnaterre, 1788 Squalus pennanti Walbaum, 1792 Squalus selanonus Leach, 1818 The porbeagle or porbeagle shark ( Lamna nasus )
24963-498: Was reported to have had fed on krill and polychaete worms . The timing of the porbeagle's reproductive cycle is unusual in that it is largely similar in both hemispheres, rather than being offset by six months. This suggests that its reproduction is not significantly affected by temperature or day length, perhaps owing to its endothermic physiology. Mating takes place mainly between September and November, though females with fresh mating scars have been reported as late as January off
25122-425: Was supposedly well-founded. Though rumours have stated this shark was exaggerated in size or non-existent altogether, witness accounts by the then young Craig Anthony Ferreira, a notable shark expert in South Africa, and his father indicate an unusually large animal of considerable size and power (though it remains uncertain just how massive the shark was as it escaped capture each time it was hooked). Ferreira describes
25281-433: Was tagged off the South African coast swam to the southern coast of Australia and back within the year. A similar study tracked a different great white shark from South Africa swimming to Australia's northwestern coast and back, a journey of 20,000 km (12,000 mi; 11,000 nmi) in under nine months. These observations argue against traditional theories that white sharks are coastal territorial predators, and open up
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