About the Great white shark
Great white sharks are at the very top of the marine food chain. Feared as man-eaters, they are only responsible for about 5-10 attacks a year, which are rarely fatal. Great whites are ultimate predators. Powerful streamlined bodies and a mouth full of terrifyingly sharp, serrated teeth, combine with super senses that can detect a single drop of blood from over a mile away. Hiding from a great white isn't an option as they can detect and home in on small electrical discharges from hearts and gills. Unlike most other sharks, live young are born that immediately swim away.
Scientific name: Carcharodon carcharias
Rank: Species
The best selling novel Jaws and the subsequent blockbuster film by Steven Spielberg depicted the great white shark as a "ferocious man eater". In reality, humans are not the preferred prey item of the great white shark.
Reproduction
Little is known about great white shark behaviour in the way of mating habits. Birth has never been observed, but pregnant females have been examined. Great white sharks are ovoviviparous (eggs develop and hatch in the uterus, and continue to develop until birth). The great white has an 11 month gestation period. The shark pup's powerful jaws begin to develop in the first month. The unborn sharks participate in intrauterine-cannibalism: stronger pups consume their weaker womb-mates. Delivery is in spring and summer.
Almost nothing is known about mating behavior. Some evidence points to the near-soporific effect of a large feast (such as a whale carcass) possibly inducing mating.
Great white sharks reach sexual maturity at around 15 years of age. Maximum life span is believed to be more than 30 years.
Adaptions
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. Every time a living creature moves it generates an electrical field and great whites are so sensitive they can detect half a billionth of a volt. Even heart beats emit a very faint electrical pulse. If close enough the shark can detect even that faint electrical pulse. 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 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 brain) at temperatures up to 14 °C (25 °F) above 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 is an example of gigantothermy. Therefore, the great white shark can be considered an endothermic poikilotherm, because its body temperature is not constant but is internally regulated.
Rank: Species
White shark
The great white shark, Carcharodon carcharias, also known as great white, white pointer, white shark, or white death, is a large lamniform shark found in coastal surface waters in all major oceans. The great white shark is very well known for its size, with the largest individuals known to have approached or exceeded 6 metres (20 ft) in length and 2,268 kilograms (5,000 lb) in weight. It reaches maturity at around 15 years of age and can have a life span of over 30 years. The great white shark is arguably the world's largest known extant macropredatory fish and is one of the primary predators of marine mammals. It is also known to prey upon a variety of other marine animals including fish, pinnipeds, and seabirds. It is the only surviving species of its genus, Carcharodon.
The best selling novel Jaws and the subsequent blockbuster film by Steven Spielberg depicted the great white shark as a "ferocious man eater". In reality, humans are not the preferred prey item of the great white shark.
Reproduction
Little is known about great white shark behaviour in the way of mating habits. Birth has never been observed, but pregnant females have been examined. Great white sharks are ovoviviparous (eggs develop and hatch in the uterus, and continue to develop until birth). The great white has an 11 month gestation period. The shark pup's powerful jaws begin to develop in the first month. The unborn sharks participate in intrauterine-cannibalism: stronger pups consume their weaker womb-mates. Delivery is in spring and summer.
Almost nothing is known about mating behavior. Some evidence points to the near-soporific effect of a large feast (such as a whale carcass) possibly inducing mating.
Great white sharks reach sexual maturity at around 15 years of age. Maximum life span is believed to be more than 30 years.
Adaptions
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. Every time a living creature moves it generates an electrical field and great whites are so sensitive they can detect half a billionth of a volt. Even heart beats emit a very faint electrical pulse. If close enough the shark can detect even that faint electrical pulse. 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 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 brain) at temperatures up to 14 °C (25 °F) above 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 is an example of gigantothermy. Therefore, the great white shark can be considered an endothermic poikilotherm, because its body temperature is not constant but is internally regulated.
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| Global range highlighted in blue |
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| White shark at Isla Guadalupe, Mexico |
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| conservation status |
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