FACT

Sharks can lose and regrow thousands of teeth in their lifetime, with some species growing new teeth every two weeks.

Source: Shark Teeth Facts - American Museum of Natural History

MYTH

Bull sharks can live in both salt and fresh water, and have been found hundreds of miles up rivers.

Source: Bull Sharks in Freshwater - National Geographic

MYTH

Of over 500 shark species, only about 10 are considered dangerous to humans. Most sharks are harmless.

Source: Shark Species and Human Risk - NOAA Fisheries

MYTH

Sharks don't sleep in the traditional sense, but they do have periods of rest and reduced activity.

Source: Do Sharks Sleep? - Discovery Channel

FACT

Sharks evolved around 400 million years ago, while trees appeared about 350 million years ago.

Source: Shark Evolution Timeline - Smithsonian Ocean