Dead sharks wash up on the shores of South Africa. What killed them? To find out, biologists cut the stinky fish open. Sliiiice!

Inside each shark, scientists find something surprising. All the sharks are missing their livers!

Great white sharks like these normally have huge livers full of fat. These oily organs help them float. The scientists do the work of detectives. “Whatever killed these sharks wanted a fatty snack,” they think. “But it didn’t want the rest of the sharks’ bodies.” They check out the bite marks and gaping wounds on the sharks’ undersides. These clues help them solve the mystery. The killer is...drumroll...a killer whale!

You might be thinking, “What?! Killer whales are friendly creatures!” That’s how these big, intelligent mammals seem in movies—even though they have a scary name. No one goes to the beach and says, “I hope there are no whales around.” But they do say, “Shark in the water! Everybody OUT!” Can gentle orcas really kill ferocious sharks?

They can. In fact, orcas can kill anything in the ocean—if they want to. They have large brains. They can use sound waves to locate other sea creatures. Orcas live in groups. They can work together to outsmart almost any prey—even large, powerful great white sharks.

Orcas aren’t the only enemies great whites have to worry about either. Sharks in the movies are portrayed as almost unbeatable enemies. But in real life, shark nets, fishing, and poaching kill sharks all the time. These factors are even greater threats than orca whales. The orcas don’t eat great white sharks often, anyway. If they did, they’d have to visit the underwater dentist. The rough texture of shark flesh grinds down the enamel on their teeth!