1. Sharks have existed for more than 400 million years, predating dinosaurs by 200 million years.

2. There are over 500 known species of shark, from hand-sized to school-bus sized.

3. The whale shark, the largest fish in the ocean, is a gentle filter feeder that eats plankton.

4. Sharks can detect a single drop of blood in about 25 gallons of water.

5. Some sharks, like the great white, can go months without eating a full meal.

6. Sharks have no bones at all - their skeletons are made entirely of cartilage.

7. A shark's skin is covered in tiny tooth-like scales called dermal denticles.

8. Hammerhead sharks have nearly 360-degree vision thanks to their uniquely shaped heads.

9. Sharks lose thousands of teeth over a lifetime and simply grow new ones.

10. Humans kill far more sharks each year than sharks kill humans - about 100 million to a small handful.