Great white shark

The great white shark, known scientifically as Carcharodon carcharias, is a massive predatory fish.

It is a robustly built species with a distinctive torpedo-shaped body. The shark uses countershading for camouflage in the open ocean. This means its upper side is a grayish color, while its underside is white. This pattern helps it hide from prey above and below. While it is one of the largest living fish, it is still smaller than the basking shark.

Several biological mechanisms allow the white shark to thrive in diverse environments. Its skin is covered in dermal denticles, which are tiny, tooth-like scales. These scales have ridges that point backward to help the shark move through water. The shark also possesses about 300 triangular, serrated teeth. These teeth are continuously replaced throughout the animal's life.

To stay afloat, the shark relies on a massive, fatty liver. This organ can reach over one-quarter of its total body weight. The fat provides buoyancy and serves as an energy store. Additionally, the shark is partially warm-blooded. This adaptation helps it remain active even in colder ocean waters.

Great white sharks are highly migratory and inhabit many different ocean regions. They live in both tropical and temperate waters across the globe. Many populations are concentrated near the Pacific and Atlantic coasts of North America. Other major groups live near Oceania and southern Africa.

Scientists have identified three distinct genetic branches, or clades, within the species. These include the North Atlantic, the Indo-Pacific, and the North Pacific. These groups diverged between 7,000 and 200,000 years ago. This separation likely happened due to changing sea levels and thermal barriers. For example, warm equatorial waters act as a barrier for many sharks.

As an apex predator, the white shark plays a vital role in marine ecosystems. It preys on marine mammals like dolphins and seals. It also eats fish, squid, and even other sharks.

When large whales die, the white shark acts as a prolific scavenger. However, the shark is not always at the top of the food chain. Orcas are known to prey on white sharks, including juveniles.

Most white sharks are solitary animals. They may only gather in large groups at specific feeding sites. In these groups, they use body language to establish dominance hierarchies.

The history of describing this shark is quite long and varied. Carl Linnaeus first described the species in 1758. He originally placed it in the genus Squalus. By 1838, Sir Andrew Smith created the new genus name Carcharodon. This name is a portmanteau of two Greek words. The prefix "carchar-" means sharp, and "-odon" means tooth.

Earlier writers had different views of the animal. In 1553, Pierre Belon described it as being similar to a dog. In 1554, Guillaume Rondelet named it "Lamia" after a creature from Greek mythology.

Understanding the true size of a white shark can be difficult. There have been many exaggerated claims about their maximum size. However, reliable measurements provide a clearer picture. In 2014, a study of Pacific catch records found a shark measuring 6.4 meters. That same specimen weighed 2,268 kilograms.

Another large specimen was a female found in the Mediterranean. This shark measured 7.4 meters in length. It was estimated to weigh 3,175 kilograms. These figures represent the largest reliably recorded examples of the species.

Today, the great white shark faces significant conservation challenges. The International Union for Conservation of Nature lists them as a vulnerable species. In the Mediterranean and European waters, they are considered critically endangered. Many sharks are lost due to accidental catching by commercial fisheries. They also face threats from recreational fishing and entanglement in protective nets.

Because of these risks, several governments have enacted laws to protect them. These laws often include bans on catching or killing the sharks to help their populations recover.