Organ pipe coral

The organ pipe coral (Tubipora musica) is an alcyonarian octocoral 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 numerous polyps. Because of this, living colonies are typically green, blue, or purple due to the color of the expanded polyps. Colonies are typically dome-shaped and can reach up to 3 meters (9.8 ft) across, while the individual polyps are typically less than 3 mm wide and a few mm long. They are close relatives to other soft coral and sea fans. This species is a popular aquarium coral due to its ease to maintain, as well as higher tolerance compared to most true corals. However, its popularity presents a problem: along with its potential as an aquarium coral, the species' coloration makes it a popular commodity for tourists, leading to a variety of threats to the population.