Great White Shark "Carcharodon carcharias"

SWIMMING

Great whites are propelled through the water by their powerful tails. The fins are only used for balance. Their movement is more like an aircraft's flight than other fishes swimming. They average about 2 mph but can swim 15 miles per hour in short bursts.
They swim constantly or they will sink since, like other sharks, they have no gas filled swim bladder to keep them afloat like bony fish do. Like other sharks, their large, oily liver provides some floating ability. They are still heavier than water and will sink unless they are propelling themselves through the water. Also like other sharks, they cannot swim backwards or even come to an abrupt stop, because their fins are not flexible like other fish. In order to go backwards, they must stop swimming and fall backwards, using gravity to propel themselves backwards.

It has been recently discovered that great white sharks can jump out of the water. They jump into the air from deep water in order to catch fast-swimming seals.

REPRODUCTION

Great white sharks reproduce via aplacental viviparity; they give birth to 2-14 fully-formed pups that are up to 5 feet long. Like all sharks, fertilization of the eggs occurs within the female. The eggs hatch within the female and are nourished by eating unfertilized eggs and smaller siblings in the womb. There is no placenta to nourish the babies - they must fend for themselves, even before birth. They swim away from the mother immediately after birth, there is no maternal care-giving.

LIFE SPAN

No one knows the life span of the great white shark. Some people estimate it to be about 100 years, but this has not been proven.
POPULATION COUNT
Great whites are decreasing in numbers and are rare due to years of being hunted by man. They are a protected species along the coasts of California, USA, Australia, and South Africa.

GENERAL DESCRIPTION

The great white shark is a ferocious predator with 3,000 teeth at any one time. This feared fish has a torpedo-shaped body, a pointed snout, a crescent-shaped tail, 5 gill slits, no fin spines, an anal fin, and 3 main fins: the dorsal fin and 2 pectoral fins. When the shark is near the surface, the dorsal fin and part of the tail are visible above the water.

COLORATION

Only the underbelly of the great white shark is actually white; its top surface is gray to blue gray. This is useful in hunting its prey. The great white usually strikes from below and its grayish top coloration blends in with the dark water, enabling it to approach the prey unobserved.

SIZE

Great whites average 12-16 feet long long. The biggest great white shark on record was 23 feet long, weighing about 7,000 pounds. Females are larger than males, as with most sharks. Shark pups can be over 5 feet long at birth.

DIET AND FEEDING HABITS

Young great white sharks eat fish, rays, and other sharks. Adults eat larger prey, including sea lions and seals, small toothed whales, otters, and sea turtles. They also eat dead animals that they have found floating dead in the water.
Great whites do not chew their food. Their teeth rip prey into mouth-sized pieces which are swallowed whole.
A big meal can satisfy a great white for up to 2 months.

TEETH

The great white shark has 3,000 teeth at any one time. They are triangular, saw-edged, razor-sharp, and up to 3 or more inches long.
The teeth are located in rows which rotate into use as needed. The first two rows are used in obtaining prey, the other rows rotate into place as they are needed. As teeth are lost, broken, or worn down, they are replaced by new teeth that rotate into place.

SENSES

Shark's primarily use their sense of smell followed by their sensing of electric charges. The shark's other senses, like sensing changes in water pressure, eyesight, and hearing, are less important.
The great white's nostrils can smell one drop of blood in 25 gallons of water. Shark nostrils are only used for smell and not for breathing, like our nostrils. They breathe using gills, not nostrils.
The sensing of minute electrical discharges in the water is accomplished by a series of jelly-filled canals in the head called the ampullae of Lorenzini. This allows the shark to sense the tiny electrical fields generated by all animals, for example, from muscle contractions. It may also serve to detect magnetic fields which some sharks may use in navigation.