CORALS - ANIMALS WHICH DON'T MOVE AROUND

Whilst adult hard corals can extend and retract their body and move their tentacles (arms), they cannot ever leave their calyx (skeletal home).

Corals do not need to move. Their skeleton provides them with the shelter they need and their food can be found in the water around them which is full of dissolved organic material and plankton (microscopic plants and animals). Corals are effective predators and are capable of stripping plankton out of the water using both their tentacles and their body mucus to sting, trap and ingest food.

While soft corals can feed all day long, with few exceptions, hard corals only feed after dusk when they emerge from their stony calyx and begin their nocturnal plankton feast. During the daytime, all that can be seen of hard corals are their skeletons. This is why these delicate animals have sometimes been mistaken for inanimate rocks.