Carcharodon carcharias

The size at birth is between 109-165 cm. The average adult body length is 140-600 cm, and the maximum can reach 800 cm. The body is fusiform, with a thick trunk, and the head and tail gradually become smaller. The tail peduncle is flat and has a lateral protrusion, and there is a depression above and below the base of the tail. The snout is short, with a blunt tip and a slight protrusion. The eyes are large and round, with vertical pupils, without nictitating membranes, located above the mouth and quite far from the first gill opening. The nostrils are narrow, closer to the mouth than to the snout, with a small protrusion on the front nasal valve, and the nasal septum is about 2.5 times wider than the nostrils. The mouth is large and arc-shaped, with the width of the mouth greater than the length of the snout before the mouth, and about 2 times larger than the length of the mouth; the lip folds are short, and the lower lip folds are hidden when the mouth is closed. The teeth are large,

Widely distributed in the coastal waters of the world's oceans. Mainly distributed in temperate oceans, some large individuals also appear in tropical waters. White sharks occasionally break into cold northern waters and have been found off the coast of Alaska and Canada. In the western Atlantic, from Newfoundland, Canada to Florida, USA, from the Gulf of Mexico to the Bahamas and Cuba in northern Mexico, from Brazil to Argentina; in the eastern Atlantic, from France to South Africa, including the Mediterranean. In the Indian Ocean, from the Red Sea to South Africa, Seychelles, Reunion and Mauritius. In the western Pacific, from Siberia to New Zealand and the Marshall Islands; near the Hawaiian Islands in the central Pacific; in the eastern Pacific, from Alaska to the Gulf of California, from Panama to Chile. In China, they are distributed in the East China Sea and the northeastern waters of Taiwan and the South China Sea.
White sharks are large and ferocious sharks in the near

The scientific name of the Great White Shark is Carcharodon carcharias, and its foreign name is Great White Shark. There are no subspecies.

The relationship between the Great White Shark and other genera in its family is controversial. Two systematic arrangements have been proposed. One holds that it is more closely related to the mako shark (Scombridae), while another holds that it is still more closely related to the oceanic porbeagle shark (Scombridae). Recent studies have shown that the first hypothesis is better. Paleontological studies based on tooth fossils indicate that other genera of the porbeagle shark family (Scombridae and Scombridae) originated in the Paleocene or early Eocene. The fossil record shows that porbeagle sharks (Scombridae) were abundant and diverse in the late Cretaceous and Paleocene. The evolution of the white shark also presents a variety of theories, one that it evolved from the megalodon, and another that it evolved from the mako shark of the Miocene.

Although information on the movement of the white shark is limited, tagging and release programs in the United States, South Africa, and Australia have shown that the white shark is capable of local, regional, and intercontinental movement. Generally larger individuals travel long distances throughout the ocean basin. Observations of two white sharks swimming in open water showed that they would also swim slowly and steadily up and down, and quickly down, when not feeding. White sharks are also capable of short, high-speed pursuits and even sprints from the water. Movements and abundance patterns in some areas appear to be related to seasonal changes in surface temperature. Movements and abundance patterns in some areas appear to be related to seasonal changes in surface temperature. However, this is likely to have little impact on the distribution of white sharks.

The white shark is a large predator that is active during the day. It preys on a variety of fish, sharks, rays, cephalopods, crabs, seabirds, turtles, seals, dolphins, whales, animal carrion, etc., and has been recorded attacking ships and humans. The most important prey are marine mammals, including sea lions, elephant seals, and fish, including other sharks and squid. Marine reptiles (mainly turtles) are occasionally swallowed. Seabirds and sea otters are not eaten, as these animals are often found injured from encounters with white sharks but are not known to have been devoured.

The predatory behavior of white sharks is generally divided into five stages: discovery, recognition, approach, conquest, and consumption. However, these stages, especially the first and second stages, are poorly understood in white sharks. Prey detection and recognition patterns of white sharks have been studied using experimental targets, lures, and other objects that "offer" prey to sharks. These experimental results indicate that when white sharks are given a choice between a square target and a fusiform or seal-shaped target, they choose the shape that is more common in the natural environment. In fact, the choice made in nature is usually whether to respond to one potential prey item, rather than choosing between two of them. When only one object is presented, it is always investigated. Some scientists believe that the silhouettes of divers and surfers observed from below are similar to those of pinnipeds, and this misidentification on behalf of sharks is also the reason for most white shark attacks on humans. However, the fact that white sharks attack inanimate objects of various shapes, colors, and sizes, none of which resemble marine mammals, contradicts the commonly known "mistaken identity" hypothesis. Researchers believe that white sharks often attack unfamiliar objects to determine if they are edible. In this case, grasping an unfamiliar object appears to be the only reliable way for white sharks to determine palatability.

Based on underwater observations, scientists describe approach patterns. Most sharks use an "underwater approach" where they swim just below the surface until they are about 1 meter from their intended prey, then attack by deflecting their heads upward and surfacing from the water. White sharks also exhibit a "surface charge" consisting of rapid impacts with parts of their body above the surface. On rare occasions, white sharks adopt an "inverted" approach, swimming with their ventral side facing up. Although most approaches are horizontal, vertical approaches are also common. White sharks are prone to vertical swimming during foraging activities, sometimes chasing floating objects directly and quickly perpendicular to the water surface. There are many advantages to using a vertical approach to capture prey close to the surface. First, a predator attacking from below is harder to see for the prey, and at the same time, the white shark can better see its prey's position overhead. In addition, fleeing (quickly running away from an approaching predator) is probably the most commonly used escape strategy by the attacked animal. Given these circumstances, it would be almost impossible to escape by extending in the opposite direction of a vertical approach to a white shark. The tendency to swim vertically has been observed in small white sharks, which are about 220 cm long. Scientists believe that the development of this behavior preceded physiological changes, such as the widening of teeth, which are considered an adaptation to feeding on large marine mammals.

Few assumptions have been made about the consumption pattern of white sharks based on observations under natural conditions. One of the assumptions, the "bite, spit and wait" theory, consists of three elements. Initially, the white shark grabs the prey and releases it intact; second, the white shark waits for the prey to go into shock or bleed to death; and finally, the white shark returns to eat the dead or dying animal. However, later studies did not support this hypothesis. Scientists believe that white sharks may not release potential prey to die, but instead let go in response to the prey's defensive behavior or unsuitability as food. Some evidence suggests that white sharks determine the palatability of prey in their mouths. Researchers also believe that white sharks may prefer energy-rich animals, such as marine mammals, over energy-poor prey with low fat content. Certain observations suggest that white sharks selectively feed on blubber rather than on the muscle layer of whales. This behavior appears to be based on a size hierarchy in which large sharks dominate in feeding.

A behavioral pattern called "repeated aerial opening" has been observed in white sharks in southern Australia. White sharks are seen with their heads out of the water, their mouths at or above the water, rolling sideways, and rhythmically opening and closing their mouths while swimming slowly on the surface. The most notable difference between this behavior and normal surface feeding is that the repeated aerial flaring is not directed toward food or possible targets. White sharks also forage from fishermen's nets and longlines, and take a variety of baits. This often results in their own accidental entrapment.

White sharks are active and fast swimmers, with an average cruising speed of 3.2 kilometers per hour, capable of sudden rapid sprints, and sometimes leaping out of the water. They are the largest of the predators. They swim alone or in pairs, or can be found in groups of 10 or more on feeding migrations, but do not gather in large groups. Some of the white shark's swimming patterns, such as carefully timed turns when two white sharks approach each other, have been interpreted as conspecific avoidance to maintain personal space. The parallel swimming pattern, in which two white sharks heading in the same direction maintain a fixed distance from each other, also appears to be a way for these animals to maintain their personal space. It is thought that when two white sharks are targeting the same prey, they use body movements to deter each other. White sharks have been observed to exhibit "tail slapping" behavior, where they slap the water with their tail fin and push water toward another white shark competing for the same resource. They also exhibit other types of behaviors. They have been observed rolling sideways and directing exaggerated tail slaps in one direction, a phenomenon known as "tilting behavior." Sometimes, a white shark will position itself between its intended prey and another white shark to prevent the second shark from feeding. White sharks will also push two-thirds of their bodies out of the water and then lie flat on the surface, causing a huge splash. This behavior is known as "pattern breaking" and may represent a signal similar to but more intense than tail slapping. This particular behavior may also be used to help remove external parasites, attract a mate during courtship, or may be the result of a vertical dash toward prey.

Males mature at about 350-410 cm in length, and females at about 450-500 cm in length. Ovoviviparous. The embryos hatch in the uterus and are nourished by ingesting unfertilized eggs until the female gives birth. While in the uterus, the embryos eat their own teeth, perhaps to recycle calcium and other minerals. Gestation time is unknown but is believed to be 1 year or more, with females giving birth every 2-3 years and litters ranging from 2 to 17. Some bite marks have been observed on the back, sides, and especially pectoral fins of female white sharks, which have been interpreted as mating scars. As with other species of sharks, male white sharks may grab females during mating. May live to be over 70 years old.

The white shark has a record of attacking fishing boats and biting people. It is one of the three most dangerous sharks to humans. Most attacks on people usually occur on shallow beaches. In order to prevent shark damage, some countries with many sharks have to set up "Shark Prevention Committees". In 1958, the United States established the "Shark Research Group", which filed all cases of shark attacks on humans since 1952 in the world, numbered them, and analyzed them one by one using electronic computers, and finally discovered the secret of sharks eating people. Scientists have come to the following conclusions:

First, sharks eating people is related to water temperature. When the sea water temperature is below 20-21℃, sharks rarely attack humans, while in tropical seas with higher water temperatures, especially in the eastern seas of Australia, sharks often attack people.  

Second, sharks eating people is related to water depth. They found that among 470 shark attacks, 62% occurred in shallow waters below one and a half meters.  

Third, sharks eating people is related to time. Usually most shark attacks occur between 11 a.m. and 6 p.m., which is when people are more likely to engage in underwater activities and sea bathing. However, it is generally recognized that the most dangerous time is at night.

Fourth, sharks eating people is related to the smell of blood. It is said that once sharks smell blood, they will immediately become beastly and rush towards the other party without hesitation, open their bloody mouths, and swallow the stranger. In addition, sharks eating people is also related to gender. A large proportion (about 93%) of attacks are against men. In addition, shark bites often occur in the rainy season from May to August every year, especially the morning after a thunderstorm. Sharks like to bite people the most, so you must not swim early after a thunderstorm.

The global population size estimate for the Great White Shark is unknown and regional estimates are unreliable. Some have proposed that Great White Sharks should be protected because of their position as top predators in the marine food web. Like most sharks, Great White Sharks grow slowly and have few young, making them highly vulnerable to overfishing. Fortunately, for Great White Sharks, the threat of habitat loss is not significant. They are highly adaptable predators that are able to change their diet depending on conditions and may migrate from areas where food is scarce. The greatest challenge to effectively managing Great White Shark populations is the lack of accurate data related to fecundity, age, growth, and population size.

In 2012, the General Fisheries Commission for the Mediterranean (GFCM) banned the retention of white sharks and 23 other elastic branch fish listed in Annex II of the Barcelona Convention and authorized their cautious release. However, implementation by GFCM Parties has been very slow. To prevent overfishing and recovery, it is recommended that all commitments to protect white sharks under international wildlife treaties be fully implemented. For the Convention on Migratory Species (CMS