Why Are Sharks So Amazing?

What You'll Learn

• Sharks have a special sixth sense that detects electricity from other animals' muscles
• A shark's teeth are arranged in rows — new teeth move forward like a conveyor belt
• Sharks have existed for over 400 million years — longer than dinosaurs
• The whale shark is the biggest fish in the ocean — as long as a school bus
• Sharks help keep the ocean healthy by eating sick and weak fish

Words to Know

Cartilage

A tough but flexible material — like what your nose and ears are made of

"A shark's skeleton is made of cartilage, not bone."

Electroreception

A sixth sense that lets sharks feel electricity from other animals

"Sharks use electroreception to find hidden fish."

Apex predator

The top hunter in a food chain — nothing hunts it

"Sharks are apex predators of the ocean."

Conveyor belt

A moving strip that carries things along — shark teeth work like this

"New shark teeth move forward like a conveyor belt."

Check What You Learned

Fun Facts

• Sharks have existed on Earth for over 400 million years, predating dinosaurs by about 200 million years

  Source: Smithsonian National Museum of Natural History

• Shark skeletons are made of cartilage, not bone — the same flexible tissue that makes up human noses and ears

  Source: National Oceanic and Atmospheric Administration

• The whale shark is the largest fish in the ocean, reaching lengths of up to 40 feet (12 meters)

  Source: NOAA

• Whale sharks are filter feeders that eat primarily plankton and small fish

  Source: NOAA

• Sharks have a sixth sense called electroreception — special organs called ampullae of Lorenzini on their snouts detect electrical signals from other animals

  Source: Shark Research Institute

• A great white shark can detect one drop of blood in 100 liters of water

  Source: National Geographic