The Organ pipe coral (Tubipora musica) is a coral native to the waters of the Indian Ocean and the central and western regions of the Pacific Ocean . It is the only known species of the genus Tubipora. This species is a soft coral but with a unique, hard skeleton of calcium carbonate that contains many organ pipe-like tubes. On each tube is a series of polyps which each have eight feather-like tentacles. These tentacles are usually extended during the day, but will swiftly withdraw with any sort of disturbance. The skeleton is a bright red color, but is typically obscured by the numerous polyps, which are green or gray in color. In size, colonies can reach up to a meter across, while the individual polyps are typically less than 3 mm wide and a few mm long. They are restricted to shallow waters and tend to live in sheltered areas.They eat plankton. Humans are their main predators. They are close relatives to other soft coral and sea fans.