~ The Great White Shark ~
Carcharodon carcharias (great white shark) belongs to a family called mackerel sharks. Like all other sharks, the white shark's skeleton is cartilaginous (composed of cartilage) instead of bones. The great white shark is a robust, torpedo-shaped, conical-snouted species with a normal assortment of dorsal, anal, and paired fins. Unlike most sharks, but like other mackerel sharks, the upper and lower lobes of its tail are almost equal in size. This indicates that it swims constantly (because it must swim to breathe) and sometimes rapidly. White sharks are powerful swimmers and can swim up to 15 miles per hour in short bursts.
Great whites can grow up to 25 feet long and weigh thousands of pounds. Its ancestors, now extinct, were twice this size, with teeth that were up to 6 inches long! The narrow teeth at the bottom jaw are used to grab and hold prey. Serrated triangle shaped teeth on the top jaw are used for cutting. The rough edges help the teeth cut more easily. To be able to have a greater force of biting, the white shark can detach its upper jaw from its skull.
White sharks are ovoviviparous, which means that the eggs hatch and the babies develop inside the female's body but there is no placenta to nourish the pups. The pups eat any unfertilized eggs and each other until they are born. The babies, or pups, are born alive, fully formed and ready to hunt for food. White shark pups may be 4 feet long at birth and have a full set of teeth. Females give birth to seven to nine live pups per litter, and are thought to produce only four to six litters in a life time. The young do not mature until about 10 to 12 years old. The white shark is believed to live between 30 to 50 years.
A wide ranging shark, the white shark makes its home in both the Atlantic and Pacific oceans, from tropics to the icecaps. This shark is usually found in deeper water over the continental shelf, a flat part of a submerged continent which drops off to the ocean floor. However, a white shark will occasionally enter into shallow water quite close to shore where it finds most of its food.
White sharks begin life by feeding on fish, rays, and other sharks, and as they grow, then switch to feeding on marine mammals and scavenging on large animal carcasses. Their first mammalian prey are usually small harbor seals, but as the sharks increase in size, they become large enough to eat sea lions, elephant seals, and cetaceans (dolphins and small whales). The shark's attack strategy consists of a swift, surprise attack from below, inflicting a large, potentially fatal bite. The pinniped often dies from massive trauma or blood loss, but the bites may be superficial or misplaced on the body, allowing the animal to escape and survive the attack with its scars as witness. Large white sharks will also scavenge on the carcasses of whale sharks, and on the fat-rich blubber layer of dead whales. They will occasionally feed on sea turtles and sea otters, and are known to attack, but not eat, humans. The fact is that there are only one or two reports per year of a great white shark injuring a human.
Great whites usually kill and eat sick and weak animals so in their attempt to eat and stay alive they are helping the natural chain of other animals to become stronger. They are an extremely important part of the ocean eco-system.
It was thought for a very long time that there was nothing that could threaten a great white shark, but it is now known that orcas (killer whales) can attack and kill a great white.