Fire corals are not true corals. Fire corals are members of the Cnidaria phylum, and although fire coral looks like coral, it is more closely related to jellyfish and other stinging anemones.

Fire corals have a bright yellow-green and brown skeletal covering and are widely distributed in tropical and subtropical waters. Divers often mistake fire coral for seaweed, and accidental contact is common. The very small nematocysts on fire corals contain tentacles that protrude from numerous surface pores (similar to Jelly Fish stings). In addition, fire corals have a sharp, calcified external skeleton that can scrape the skin. Orders Stauromedusae Coronatae Semaeostomeae - Disc jellyfish Rhizostomae Jellyfish (also called jellies or sea jellies as they are not true fish) are animals that belong to the Class Scyphozoa (from Greek skyphos cup and zoon animal) which is in the Phylum Cnidaria. ...