Organ Pipe Coral

The organ pipe coral is one of the few octocorals that builds a hard, permanent skeleton. The skeleton consists of thin red calcareous tubes standing side by side and horizontal platforms that link these tubes together at regular intervals; it looks like the pipes of a church organ. The red color belongs to the skeleton itself and remains after the coral dies. A green, gray or whitish polyp with eight feathery tentacles opens from each tube; with the polyps open the skeleton is almost invisible.

The family Tubiporidae is listed in CITES Appendix II; importing it requires permits. Wild-collected colonies adapt to the aquarium with difficulty; aquacultured or farmed colonies are much hardier and should be preferred.

• Moderate to strong light (about 150–250 PAR) and moderate, intermittent flow; detritus should not build up between the tubes.
• A secure spot in the middle zone of the rockwork; the skeleton is brittle and must not be crushed when placing it.
• KH 7–11 dKH, calcium 400–450 mg/L, magnesium 1250–1350 mg/L; values should be stable.
• It is sensitive to copper. It looks better in a mature aquarium with some nutrients than in very stripped water.

It gets a significant share of its nutrition from zooxanthellae, but its polyps also filter fine particles. Phytoplankton, rotifers or very fine powdered coral food 1–2 times a week noticeably supports its health, especially in aquariums with few fish.

It has no stinging tentacles and is not aggressive; over the long term its base can slowly spread over the adjacent rock. It is itself sensitive to stinging LPS corals, anemones and leather corals that wage chemical warfare; leave 15 cm of clear space. Butterflyfish and some angelfish may pick at the polyps.