The white shark, or great white, is one of the most powerful predators in the ocean and has a reputation as a killing machine. In fact, this shark is intelligent and is capable of complex social interactions. It is, however, first and foremost a predator, feeding on prey that ranges from small fish to tuna, marine mammals, purposes, seals, and sea lions, and birds, such as gannets and penguins.
Its powerful, tapered body and crescent-shaped tail are designed for sudden, swift attack, which may occur with such momentum that the shark leaves the water. It can sustain high speeds even in cold waters because it can maintain a body temperature well above that of the surroundign water due to adaptations in its circulatory system. This means that the sahrk's metabolism is more efficient than that of other sharks, allowing it to swim faster and with greater endurance.
Large numbers of these sharks are attracted to areas where there are sea mammal colonies, such as off South Africa. This species is about 16 feet (5 meters) long and as heavy as a large car. None on record has been known to exceed 7 meters.
A Great White Shark's body is covered from head to tail from placoid scales or dermal denticles, an assemblage of minuscule scales or "teeth." By virtue of their strength, design and arrangement, these scales efford the shark two important advantages. First, they act as armor, protecting the fish from major injuries; and secondly, they minimize friction the shark would encounter when swimming. As water passes over the shark's skin, it forms a film between the denticles, reducing turbulance and allowing the shark to glide in a near-frictionless mannner.
Small black dots on the shark's snout are pores that lead to the ampillae of Lorenzini, small jelly-filled cavities that can detect minute electrical current discharged by living creatures. A Great White's sense of smell allows it to detect minute traces of chemicals in the surrounding water and follow the trace back to the source, which can sometimes be several miles away. They do this by assessing the slightly different chemical concentrations flowing each nostril, and following the higher concentration. Great white Shark
Photo source: Wikipedia
Great Whites, as with all other shark species, have many rows of teeth, with only the first few being functional at any one time. Teeth fall out or break regularly and are replaced automatically throughout the shark's life. A Great White's hearing system is very different from our own three-part ear system. The shark has only inner ear and all sound vibrations pass directly through the shark's skin and tissue frotm the surrounding water. A Great White can also sense and pinpoint the origin of vibrations with another organ, its "lateral line" system. This is a series of sensory pores along the head and sides of all sharks, by which water currents, vibrations and water changes are detected. An injured or sick fish will swim more clumsily and would create much stronger pulses than a fish swimming normally and creating little turbulence These irregular pulses would trigger that shark's lateral line receptors from much further away than would the regular, more muted pulses produced by a healthy fish.