Anemones and Corals: Anthozoa

Physical characteristics: Black coral grows in densely branched treelike colonies that reach a height of more than 16 feet (5 meters). The tiny white polyps are arranged in rows. Six tentacles surround a raised mouth. The skeleton is made of a black protein and is covered with spines.

Geographic range: Black coral lives only in waters near southwestern New Zealand.

Habitat: Black coral attaches itself to the walls of narrow inlets from the sea that are 13 to 328 feet (4 to 100 meters) deep.

Black coral grows in densely branched treelike colonies that reach a height of more than 16 feet (5 meters). (© Doug Perrine/SeaPics.com)

Diet: Black coral eats animal plankton, which it captures by direct contact with its tentacles.

Behavior and reproduction: Black coral has sweeper tentacles that are up to eight times longer and more densely covered with stingers than other tentacles. The coral uses these tentacles in aggressive competition for space. Black coral has separate sexes. The male releases sperm into the water. After development inside the female, the larvae are born freely swimming.

Black coral and people: The skeleton of black coral is used to make jewelry.

Conservation status: Black coral is not threatened or endangered. ∎