Lionfish
Lionfish go by a variety of nicknames, including dragon fish, zebra fish, and fire fish. Swimming lazily around a coral reef, these bright beauties look harmless. But their pretty colors are actually a warning: Stay away! When lionfish are disturbed, or when they're chasing other fish and shrimp, watch out. Hollow spikes along their fins stand up. The sticky six-inch spikes can shoot painful, deadly venom into anyone who touches them.

Parrotfish
Parrotfish may chance colors many times during their lifetime. But that isn't the biggest chance they can make. Some are born females, then turn into males. It's easy to see how parrotfish got their name. Their teeth form a shape like a parrot's beak. The beak is useful for scraping up coral reef plants called algae. Sometimes parrotfish bite off chunks of coral and grind them up to get at the algae. Once it's digested, the coral comes out as sand!
 

Sea Catfish
Catfish called gafftopsails live along the Atlantic seacoast. They use their chin whiskers, or barbels, to feel for food on the ocean floor. Gafftopsails have a strange way of raising a family. Females lay as many as 55 eggs at a time. Until the eggs hatch, male catfish carry them around—in their mouth! While waiting for the eggs to hatch, males don't eat. Even after the babies are born, some devoted dads lug them around for an extra two weeks!