Octopus Coral

Description:

Also known as Galaxea Coral, Galaxy Coral, Bristle Coral, Tooth Coral, Starburst Coral, and Green Star Coral. Its tentacles are extended during the day. Colonies of this type of coral are usually low-growing and cushion-shaped, depending on the substrate. Corallites are of mixed size, tentacles and septa of contrasting colors. They feed on plankton.

Habitat:

Found over protected coral and rocky reefs, at depths of 5 to 20m. More dominant on inshore, fringing reefs. Widespread in the Red Sea, the Indian Ocean and in the Western Pacific.

Notes:

I suppose this is called "octopus coral" due to how it looks when the corallites' tentacles are extended. When not extended, however, the colonies appear bristly like the skin of jackfruit.