1) Like many mammals, including humans, sharks have a large heart with four separate chambers.
2) Up to 100 million sharks are killed by people every year. While the average number of people killed a year by sharks is 5.
3) Apart from people, a shark’s greatest enemy is another shark. Most sharks will happily eat any of their relatives, including members of their own species.
4) No one has ever seen a Great White Shark give birth or mate in the wild.
5) The Whale Shark is the world’s largest fish. The Whale Shark can live to be 70 years old.
6) Of the more than 350 species of sharks, only 20 species are a threat to people.
7) Scientists think that ancestors of sharks lived more than 400 million years ago—about 200 million years before dinosaurs. The main types of sharks living today evolved by 100 million years ago.
8) Two-thirds of a shark’s brain is dedicated to its keenest sense-smell.
9) Sharks never run out of teeth. A shark may grow and use up to 20,000 teeth in its lifetime. If one is lost, another spins forward from the rows and rows of backup teeth.
10) Sharks can have from 1 to 100 babies at a time, depending on the type of shark.