- Sharks become immobile when upside down.
- 70% of the world's oceans are shark-free.
- 80% of the shark species do not grow over 2 meters.
- About 25 species of sharks are known to attack people.
- Sharks never run out of teeth. If one is lost, another spins forward from the rows and rows of backup teeth.
- Megalodon was an ancient shark that may have been 40 feet (12 m) long or even more.
- The whale shark has the biggest mouth among sharks.
- The fastest swimming sharks are the mako sharks and blue sharks.