Tear-lobed Coral

Found attached to rocks or imbedded in the sand, over shallow, sandy seabeds, of coral and rocky reefs. Corals are oval or circular, and vary in colour, tentacles are only extended at night, during the day the mantle is inflated with water, making the toothed primary septo-costae clearly visible.

Stony corals have hard stony skeletons, their polyps have six tentacles or are made up of multiples of six. These are usually nocturnal, however if the sky's are overcast, then many will feed during the day.
Generally the more robust corals life on exposed areas, while the smaller corals live in sheltered lagoons or deeper waters.
Stony corals are reef building corals and embedded in their flesh are thousands of minute single-celled marine plants called zooxanthellae which accounts for their colour.
These corals support a huge diversity of life, their main predator being the crown-of-thorns sea star.