Description

Also known as Anemone Mushroom Coral, Disk Coral, Long Tentacle Plate Coral, Long-tentacled Plate Coral, Mushroom Coral, Plate Anemone, Plate Coral, Torch Coral.

Found singly, free living and flat, with a central mouth, over shallow waters, of coral and rocky reefs, with the polyps open day and night. Colours vary from a pale or dark, green/blue or grey tentacles, with pink or white tips.
This coral resembles the Stichodactyla mertensii and Bald-tipped coral - Euphyllia glabrescens.
They feed on zooplankton.
Length - 20cm
Depth - 0-25m
Widespread Indo-Pacific

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. (edit) Ref: https://en.wikipedia.org/wiki/Heliofungia_actiniformis