Sponges inhabit corals for the purpose of protection from predators. Polychaetes such as Hermodice carunculata and Gastropods in the family Trochidae depend on corals for food. They feed on corals such as Porites and Agaricia . Decapod crustaceans such as shrimps and crabs depend on corals for shelter. Xantid crabs form cavities in the coral Acropora palmata .
Fish also depend on corals for protection against predators.
Echinoderms such as Acanthaster planci are coral predators. There are many other species of fungi, sponges, sea worms, crustaceans and molluscs that bore into coral skeletons. Other organisms that inhabit the coral reefs include sea urchins, jellyfish, oysters, clams, turtles, and sea anemones.