Great White Shark
Great White Shark Senses
Great White Sharks primarily use their sense of smell followed by their sensing of electric charges. Great White sharks other senses include, sensing changes in water pressure, eyesight, and hearing. The great white's nostrils can smell one drop of blood in 25 gallons of water. 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. The great white is the only type of shark that will go to the surface and poke its head up out of the water. No one knows exactly why it does this; perhaps it is to see potential prey such as surface-dwelling sea lions.
Great White Shark Teeth
Great white sharks, like many other sharks, have rows of teeth behind the main ones, allowing any that break off to be rapidly replaced. Their teeth are unattached to the jaw and are retractable, like a cat's claws, moving into place when the jaw is opened. Their teeth also rotate on their own axis (outward when the jaw is opened, inward when closed). The teeth are linked to pressure and tension-sensing nerve cells. This arrangement seems to give their teeth high tactile sensitivity. A great white shark's teeth are serrated and when the shark bites it will shake its head side to side and the teeth will act as a saw and tear off large chunks of flesh. Great white sharks often swallow their own broken off teeth along with chunks of their prey's flesh. These teeth frequently cause damage to the great white shark's digestive tract.
Authored by Anthony DeRose
28 March 2007