Black coral (Antipathella aperta)

Description

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Black coral fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Black coral description

The Antipathella corals belong to the group of black corals (those in the order Antipatharia), named after their dark brown or black skeletons ⁽²⁾. There are five species in the Antipathella group, all of which form branched structures ^{(3) (4)}. Each polyp measures 0.5 to 1 millimetre across ⁽⁵⁾, and typically bears six simple tentacles arranged around a slit-like mouth ⁽²⁾. The skeleton is covered with a thin layer of pale, living tissue, which connects all the individual polyps ⁽²⁾, and the entire colony is covered with small protuberances ^{(4) (5)}.

Black coral biology

Unlike reef-building corals, many black corals (species in the order Antipatharia), do not possess the symbiotic algae, zooxanthellae, within their tissues. They are therefore not restricted to shallow, sunlit waters where the zooxanthellae can photosynthesise, and instead are able to inhabit deep and dark waters ⁽²⁾.

Little information appears to be available on the biology and life history of Antipathella species, other than the New Zealand species, Antipathella fiordensis (previously known as Antipathes fiordensis). A. fiordensis has separate male and female colonies ⁽⁶⁾, unlike the majority of corals which are hermaphrodite and thus possess both male and female reproductive organs. It is thought that this species reproduces primarily by spawning; eggs and sperm are released into the water column where fertilisation takes place. The fertilised egg develops into free-swimming larvae, which soon settles and attaches itself to the substrate, establishing a new colony. Spawning is thought to occur in mid- to late-summer ⁽⁶⁾. Genetic evidence has shown that A. fiordensis reproduces primarily by sexual means, but that some asexual reproduction also occurs. In a laboratory, they have been observed reproducing asexually via “polyp bail-out” ⁽⁶⁾, whereby polyps detach themselves from a colony, and form new colonies by normal budding ⁽⁷⁾. All black coral species are known to have a relatively slow growth rate and long lifespan ⁽⁸⁾.

Black coral range

Antipathella aperta occurs off New Zealand ⁽⁴⁾.

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Black coral habitat

Antipathella corals are inhabitants of temperate marine waters, and are not thought to be able to survive in water exceeding 15 degrees Celsius ⁽³⁾.

Black coral status

Listed on Appendix II of CITES ⁽¹⁾.

Black coral threats

Information regarding Antipathella corals specifically is lacking, but like all black corals, it is likely to be impacted by over-harvesting for the jewellery trade. Black coral is highly valued in the jewellery trade because its dark skeleton can be polished to a lustrous sheen ⁽⁸⁾. Identification of black corals in the trade down to the level of genus is difficult; therefore it is hard to determine the extent to which Antipathella species are affected by such exploitation ⁽⁸⁾. Black corals around the world are also known to be impacted by habitat degradation, and recently, a small trade in live specimens for aquariums has been reported ⁽⁸⁾.

Black coral conservation

Antipathella corals are listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), which means that trade in this species should be carefully regulated ⁽¹⁾.

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

For further information on the trade in corals see:

• WWF:
  http://www.worldwildlife.org/what/globalmarkets/wildlifetrade/buyersbeware-coral.html
• U.S.Fish & Wildlife Service:
  http://www.fws.gov/news/coral.html

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Glossary

Asexual reproduction

Reproduction that does not involve the formation of sex cells, such as sperm and eggs. Asexual reproduction only involves one parent, and all the offspring produced by asexual reproduction are identical to one another.

Budding

Type of asexual reproduction in which new individuals develop from the parent organism, forming a swelling similar in appearance to a bud. The ‘bud’ slowly separates from the parent as it grows.

Colony

Relating to corals: a coral composed of numerous genetically identical individuals (also referred to as zooids or polyps), which are produced by budding and remain physiologically connected.

Larvae

Relating to corals: the stages of development before settlement on the reef. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.

Photosynthesise

Photosynthesis is ametabolic process characteristic of plants in which carbon dioxide is broken down, using energy from sunlight absorbed by the green pigment chlorophyll. Organic compounds are produced and oxygen is given off as a by-product.

Polyp

Typically sedentary soft-bodied component of Cnidaria (corals, sea pens etc), which comprise of a trunk that is fixed at the base; the mouth is placed at the opposite end of the trunk, and is surrounded by tentacles.

Symbiotic

Describing a close relationship between two organisms. This term usually refers to a relationship that benefits both organisms.

References

1. CITES (September, 2009)
   http://www.cites.org
2. King, D. (1997) Reef Fishes and Corals. Struik Publishers, Cape Town.
3. Bo, M., Tazioli, S., Spanò, N. and Bavestrello, G. (2008) Antipathella subpinnata (Antipatharia, Myriopathidae) in Italian seas. Italian Journal of Zoology, 75(2): 185 - 195.
4. Opresko, D.M. (2001) Revision of the Antipatharia (Cnidaria: Anthozoa). Part I. Establishment of a new family, Myriopathidae. Zoologische Mededelingen, Leiden, 75: 147 - 174.
5. Opresko, D.M. and Sánchez, J.A. (2005) Caribbean shallow-water black corals (Cnidaria: Anthozoa: Antipatharia). Caribbean Journal of Science, 41(3): 492 - 507.
6. Parker, N.R., Mladenov, P.V. and Grange, K.R. (1997) Reproductive biology of the antipatherian black coral Antipathes fiordensis in Doubtful Sound, Fiordland, New Zealand. Marine Biology, 130: 11 - 22.
7. Sammarco, P.W. (1982) Polyp bail-out: an escape response to environmental stress and a new means of reproduction in corals. Marine Ecology Progress Series, 10: 57 - 65.
8. CITES. (2000) Periodic Review of Animal Taxa in the Appendices. Sixteenth Meeting of the Animals Committee, Shepherdstown, U.S. Available at:
   http://www.cites.org/eng/com/AC/16/index.shtml