Sharks are the most fearsome creatures on earth although more people are killed by elephants than sharks. Only five of the 375 shark species attack humans.
Sharks are cold blooded and mostly eat dolphins, seals and other fish. Adult sharks go through 7–12 sets of its hook-shaped teeth each year but have the ability to regrow new teeth. They have huge mouths and swallow food whole or in big pieces; they don’t chew. They tear at flesh or lash their bodies against victims, using the razor-sharp scales that cover their bodies. Sharks feed only a couple of times a week in the wild and are mostly solitary, living and hunting on their own.
Sharks have keenly developed senses and rely on all these working together. Twin nasal cavities are used to detect the direction of a smell. Small clusters of electrically sensitive receptor cells positioned under skin in the head are connected to pores on the skin’s surface. This electrosense enable sharks to “see” weak electrical fields generated by living organisms. A shark reaches full size when it is between 10–15 years old.
The National Aquarium has: