Stony corals, also known as Scleractinians or hard corals, are in the hexacoral family and build hard skeletons out of calcium carbonate. They are the primary reef building corals. Stony corals have tentacles in multiples of six and can host diverse species of fish and invertebrates. Two species of stony coral commonly found in the Gulf are Lophelia pertusa and Madrepora oculata (zigzag coral), with Lophelia being found much more commonly than Madrepora.
While most species of stony coral grow on hard substrate and are solitary, some species such as Lophelia can form giant, branching structures. This is not the most common type of coral found in the deep ocean though, and the 2016 Report to Congress produced by NOAA reported that “stony corals were not especially abundant or diverse. A solitary, small cup coral was the most often...
corals except stony corals and black corals, which are hexacorals. Many octocorals share similar traits: most are non-reef building, but they can provide vertical relief over areas that are otherwise soft bottoms, such as sandy bottoms. In general, octocorals tend to have large, erect frames that stretch up into the water column above the substrate, but they can also occur as smaller forms, as demonstrated by the two octocorlas found living on a deep sea chimney in the image to the left. Being above the seafloor and in the water column allows the polyps to more easily capture food from...
