In spite of its hard skeleton, the Organ-pipe coral, Tubipora musica (Alcyonacea - Tubiporidae), is actually a type of soft coral, closely related to sea fans. It is the only known species of its genus.
Its bright-red skeleton, which is made of calcium carbonate, contains many organ-pipe-like tubes (hence the name). In each tube is a series of polyps (bottom photo), each of which has eight feather- or flower-like tentacles, which are usually extended during the day.
T. musica colonies can reach up to a meter across, but individual polyps are typically less than 3mm wide and only a few millimeters long.
The Organ-pipe Coral can be found in the Red Sea, the Indian Ocean and the central and western regions of the Pacific Ocean.
Photo credit: ©Blogie [Top] - [Bottom]
Locality: Dayang Beach, Davao Del Norte, Philippines