1. Fish Without Bones: Unlike most other fish in the ocean, a shark’s skeleton is not made of hard bone. Instead, it is made of cartilage—the same flexible, rubbery material that makes up the tip of your nose and your ears!

2. Endless Teeth Factories: Sharks lose thousands of teeth during their lifetimes because they bite hard things so often. Whenever a tooth falls out, a brand-new one moves forward from rows hidden inside their gums to take its place like a conveyor belt!

3. More Ancient Than Trees: Sharks are true ocean veterans! Fossil evidence shows that sharks were swimming in Earth's oceans more than 400 million years ago, which means they have been around before land trees and even before dinosaurs walked the Earth.

4. Super-Powered Smell: Sharks have an incredible sense of smell. Some species can detect a single drop of blood in an entire swimming pool of water from hundreds of feet away!

5. Sleeping While Swimming: Many types of sharks (like the great white) have to keep swimming constantly to force water to flow over their gills so they can breathe oxygen. They can actually rest or "sleep" while still gliding forward through the water!

6. All Shapes and Sizes: Sharks come in a huge variety of looks! The dwarf lanternshark is small enough to fit right in the palm of your hand, while the whale shark can grow up to 40 feet (12 meters) long—making it the biggest fish in the sea—yet it only eats tiny plankton!

7. Mostly Harmless to Humans: Even though movies make people think sharks are scary monsters, most sharks actually ignore humans completely. Out of more than 500 different shark species, only a tiny handful have ever been involved in accidents with people.