Pillar corals are a type of hard coral which live in the western Atlantic Ocean. They are one of the digitate corals which resemble fingers, or a cluster of cigars growing up from the sea floor, but without any secondary branching. Pillar corals can grow to be up to 2.5 m (8 ft) tall. They can grow on both flat and sloping sea floors at a depth of between 1 and 20 m (65 ft). They are one of the few types of hard coral whose polyps can commonly be seen feeding during the day. Photo credit: NOAA |