Black corals are so called because the main axial skeleton is made of a spiny, keratin-like substance called "antipathin" which is a dark brownish-black. This colonial coral has a bushy, two dimensional form and grows out … See more

Plumapathes pennacea is found in tropical parts of the Indian, Pacific and Atlantic Oceans; it occurs as deep as 330 m (1,100 ft) but is most common between 25 and 60 m (80 and 200 ft), and even shallower than this in caves and under dark overhangs. It … See more

A number of other organisms live on this coral or are associated with it. Algae, hydroids and bryozoans settle and grow on the branches, and … See more