Great White Shark
One of the most feared and misunderstood creatures in all the ocean, the great white shark is one of the top predators of the sea.
Class: Chondrichthyes
Order: Lamniformes
Family: Lamnidae
Genus: Carcharodon
Species: C. carcharias
Common Names: Great White Shark, White Shark, White Pointer, Great White
Great whites are an apex predator, feeding on fish, whales, seals and sea lions, sea turtles, otters, and sea birds. They even eat other sharks, including whale sharks, the largest fish in the ocean.
Great whites have few natural predators, though orcas have been known to prey upon them. When an orca kills a great white, most of the the great whites in the area will flee. It’s believed that they are able to smell the shark that has been killed.
These sharks have a reputation for attacking humans, but these attacks are rare, and scientists who study sharks generally believe that humans do not make adequate prey for great whites, and they do not like the taste. Still, they are potentially dangerous animals and should be regarded with respect and given a wide berth.
Great white sharks are believed to reach maturity at 26years of age in males, and 33 years in females. Little is known about the mating and birthing habits of great whites, as they are difficult to observe at sea.
The gestation period for female sharks is 11 months, and they can produce up to 14 pups. While that may seem like a lot, their long gestation, slow growth rate, and late age of maturity means this shark species is especially susceptible to environmental pressures.
Great whites are ovoviviparous, meaning the sharks hatch within the mother and continue developing, until they are born live.
Great white sharks are heavy bodied, large fish with a torpedo-shaped body similar to other mackerel sharks in the family Lamnidae, which also includes the mako shark and salmon shark.
Great whites are white below, and are typically gray above, though younger sharks may be a darker gray or brown. This type of coloration is known as countershading, which makes the shark difficult to see from both above and below. This is a helpful feature for catching prey.
Great whites have numerous rows of large, sharp, serrated teeth. When a tooth in the front row breaks off, there are teeth in the rows behind that are waiting to replace it.
The name “white shark” is believed to refer to the animal’s white underside. When great whites would occasionally wash up on shore, their undersides would be the most visible part, which is thought to have led to the common name.
There have been examples of all white great whites, but these rare animals are leucistic (lacking pigment) and often die quite young for a variety of reasons.
For a long time, great whites were thought to be related to the extinct mega-toothed shark Megalodon, due mostly to similarities in their teeth. However, it is now understood that they are more closely related to mako sharks, and developed their similar teeth independently of Megalodon.
Due to the success of the novel Jaws by Peter Benchley, as well as the 1975 film adaptation directed by Steven Spielberg, the great white developed a reputation as a man-eating monster. While the shark is responsible for some attacks on humans, these attacks are rare and humans are not considered a preferred prey species for the shark.
Great whites are sometimes deliberately killed in an effort to reduce shark attacks. This practice is criticized by environmentalists because it not only harms the ecosystems that rely on the shark as a top predator, but it also has not shown to be effective in reducing attacks on humans. Peter Benchley would later regret his role in popularizing the great white as a villain, devoting much of his later life to promoting shark conservation.
While the shark has a reputation as a threat to humans, the truth is that the sharks have much more to fear from us than the other way around. They are considered a Vulnerable species by the IUCN, though it is difficult to know just how many great whites are out there.
Though they have near worldwide distribution, they are fairly uncommon, and are especially vulnerable to overfishing and environmental issues due to their slow growth and maturity rate.
A few attempts have been made to keep great whites in captivity. These are almost always unsuccessful, and the sharks often refuse to eat. If they do not pass away, they are usually released back into the wild before too long. Monterey Bay Aquarium in California has housed several great whites for various amounts of time, but they have announced they have no further plans, as they have obtained all their desired scientific data on captive white sharks.
References
https://en.wikipedia.org/wiki/Great_white_shark
Castro, Jose I. (2011). The Sharks of North America. NewYork, New York: Oxford University Press, Inc.
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