Common name : pipe-organ coral

Aspect : Unique among corals for having a rigid, red, calcareous skeleton made of parallel tubes (like organ pipes); t forms colonies of interconnected vertical tubes made of a hard calcium carbonate skeleton, arranged in parallel platforms that create a dome-shaped mass, which can grow up to 3 meters (9.8 ft) across; NB The skeleton is bright red but usually hidden by the living tissue (the overall colony color varies—often green, blue, or purple—due to the expanded polyps)

Feeding : autotrophic feeding (primary) and heterotrophic feeding (supplementary). Primarily, they rely on photosynthesis from symbiotic dinoflagellate algae (zooxanthellae) living within their tissues, which provide up to 90% of their nutritional needs through sunlight. They supplement this by actively capturing zooplankton and other small particles using the tentacles of their polyps, especially at night when polyps extend fully

Environment : tropical waters of the Indo-Pacific region, including the Indian Ocean, the Red Sea, the west Pacific (south of Japan), and east Africa's coast, extending to the central and western Pacific; in shallow, sheltered reef environments such as lagoon flats, bedrock areas, sandy grooves, and mid-shelf reefs, typically at depths of 2–20 meters, with peak abundance around 8–10 meters