Black coral is a group of thorny corals which in Latin are called Antipatharians, these corals does like all other corals consist of colonies of small animals called polyps. It is these small animals who over time create the large formations which we in daily talk call corals. The skeletons from Black corals are common in jewellery and are the Hawaiian national gem. The living corals are considerable rarer then their skeletons that are used in jewels. Corals from the Antipatharians group can display a number of different colours depending on the species in question and not only black. There are in total over 150 species of black coral described and more being discovered. About ten percent of these can be found in the waters around Hawaii where a large amount of the black coral jewellery are created. The collection of black corals for use in the jewellery industry as well as for other uses such as nature medicine has caused the Black coral populations to diminished and harvesting regulations are on their way. Research to propagate black coral in aquarium condition are being done and are making progress which may open up for black coral farming leaving the wild populations room to recuperate. This research may also cause black corals to become more common in aquariums.
The Black Coral polyps are short and cylindrical. They each have six tentacles that are covered with stinger cells. Black coral polyps are not able to retract their tentacles.
Black corals are found all around the world even if the are most common in tropical and subtropical seas. Different species of black coral can be found from shallow depths of 1m/3ft to depths up to 6000 m / 20 000 ft where no light can reach them. Black corals are often found in dark areas where they are exposed to relatively strong currents. The corals are dependent on these currents to bring them plankton to eat. It seems that the primary factor that controls the re growth within the populations of black corals are the availability of suitable habitats. Black corals larvae seem to be sensitive to light and that the corals therefore prefer relatively dark habitats. This theory is supported by the fact that black corals are found in much larger numbers below a depth of 35m/ 120ft where less light is able to reach them. Black corals also lack symbiotic algae that many other corals keep which makes them more adapted to live in deeper darker waters. Black corals grows up to 6.5 cm / 2.5 inches each year.
They are able to reproduce both sexually and asexually. The sexually reproduction involves the polyps releasing egg and sperm into the water where the currents are left to make sure that fertilization is achieved. A large number of different colonies usually spawn at the exact same time. The fertilized eggs then develop into planulae, black coral larvae, which drift in the currents until they find a suitable place to attach themselves and start a new colony. The polyp then forms new polyps and a small colony is formed. This later phenomena is an example of their asexual reproduction. The sexual reproduction is in other words used to colonics new areas and from new colonies while the asexual reproduction is used within colonies to make the colony grow.
Black corals are not suitable for most reef aquariums as they have different demands than most other corals. One such difference is the fact that black corals prefer little lighting unlike many other corals and are more dependent on being given a steady stream of plankton to feed on. Black corals can however be a nice addition for a more experienced aquarist how is knowledgeable about keeping corals and devoted to giving the black corals what they need. They are however not suitable for beginners or intermediate aquarists. Black corals are only occasionally available in aquarium stores and more information about how to keep them in aquariums might become available as more people share their experience with them.
Didn't find the info you were looking for? Register for free and ask your question in our Aquarium forum !
Our knowledgeable staff usually responds to any question within 24 hours
Aquarium coral - An introduction to aquarium coral.
Fiji live rock - An article about Fiji live rock and its origin.
Growing and Propagating Reef Corals - An article about how to Grow and Propagate Reef Corals
Leather corals - Information about Leather corals