Many people think fire coral are plants, but they are animals! Each mass of fire coral that you see is actually hundreds of tiny animals living together. Each tiny animal is called a polyp. Hundreds of coral polyps living together are called a colony.

Fire coral are cnidarians. That means they have a sac-like body with a mouth and tentacles on top. Jellyfish and anemones are also cnidarians. One major thing that makes fire coral different from jellyfish is that they have skeletons. Their skeletons are on the outside, like our armor. They add to our armor every year, and that’s how they grow bigger and bigger. Fire coral only live in the top most layer of their skeleton. The parts underneath are just old skeleton. It’s this old skeleton that makes reef!