Not all corals are found on island coasts or in shallow seas. In fact, over half of all known coral species are found in deep, dark waters where temperatures range from 4-12°C (39-54°F). For this reason, we call these corals the “cold-water” or “deep-sea” corals. They are found all over the world. Some locations are home to just a few corals while others feature dense coral mounds.
Soft corals, such as sea fans or sea pens, are named such because they lack the hard calcium carbonate skeleton that is seen in hard corals. Octocorals are identifiable due to the eight tentacles that surround the mouth of each polyp. Bamboo corals are a specific type of octocoral that is easily identifiable due to their distinct branching pattern at nodes and internodes. Bubblegum corals are recognizable due to their bulbous branches and tips. Black corals are named for their black skeleton, which lies under colorful polyps.