Truth or Lie?--Sharks

Baby sharks have teeth when they are born. They need to take care of themselves right away. They catch their own dinner. And they protect themselves so they don't become someone else's dinner!

Not true, because the skin of a shark is very tough. It is covered with denticles (say DENT-uh-kulz). Denticles are tough scales. They are made of the same strong material as a shark's teeth. So a shark's skin is like a suit of armor. This helps prevent its body from getting hurt.

You can easily see a shark's eyes and gills. But a shark's ears are inside its head, through 2 small openings on either side. Sharks also have another way to "hear" movement. Special pores along their bodies detect vibrations in the water. So never try to sneak up on a shark!

Sharks don't have any bones, not even a funny bone! A shark skeleton is made of cartilage. Cartilage is lighter and more bendable than bone. This gives many sharks, like the shortfin mako shark, the flexibility that helps them swim and turn so fast.

A shark doesn't have a "puff fin." But a shark does have several kinds of fins, each with a different job. A shark uses its caudal fin (or tail fin) to propel itself through the water. Pectoral fins are for steering. Dorsal fins help in making sudden turns. The pelvic and anal fins are used for stability. The shape and position of a shark's fins can tell us where it lives and how it hunts.

Sharks actually lose and replace their teeth constantly. Some go through up to 50K teeth in a lifetime. Have you ever lost a tooth while biting into an apple? Just like you, sharks can lose teeth when chomping into a meal. And some sharks (like the goblin shark and the cookie-cutter shark) have very unusual ways of chomping!

Screwdriver sharks don't exist, but hammerhead sharks do. Their unusual head shape, eye position, and special sensors help them hunt for food hidden in the sand.

Whale sharks are the biggest sharks. Some are up to 40 ft. long! But they are gentle giants. They swim with their huge mouths open to collect tiny animals and plants called plankton. Each day, a whale shark can eat at least 50 lbs of plankton.

People breathe air, but sharks breathe water through their gills. It's true some kinds of sharks must always swim in order to keep water moving through their gills. But other sharks have small openings behind their eyes called spiracles (say SPEER-uh-kulz). Spiracles force water across these sharks' gills so they can still breathe while they rest.

Fewer than 100 people are injured by sharks each year. Between 73M and 100M sharks are killed by people each year! Scientists and activists are trying to reduce that number by showing how sharks keep our oceans healthy. Really important dude!