Sunday 19 May
Stony coral (Barabattoia amicorum)
Stony coral fact file
- Find out more
- Print factsheet
Stony coral description
One of only two coral species belonging to the Barabattoia genus, Barabattoia amicorum is an uncommon component of coral reefs, which forms small, colourful mound-shaped colonies. Like other colony-forming corals, Barabattoia amicorum colonies are composed of numerous small polyps, which are soft-bodied animals, related to anemones. Each polyp secretes a hard skeleton called a corallite, which forms the bulk of the colony, with the living coral tissue comprising a thin veneer over the surface. In this species, the individual polyps form short, tubular mounds, that project from the surface of the main body of the colony. Each distinct, cylindrical unit has a ridged outer wall bearing numerous tiny tentacles, which surrounds a central depression—the oral disc—with the polyp mouth positioned in the middle. The polyp tissue varies in colour, exhibiting shades of brown, green or cream, with a paler oral disc (3).Top
Stony coral biology
Like many coral species, Barabattoia amicorum is zooxanthellate, which means that its tissues contain large numbers of single-celled algae called zooxanthellae. The coral and the algae have a symbiotic relationship, in which the algae gain a stable environment within the coral's tissues, while the coral receives nutrients produced by the algae through photosynthesis. By harnessing the sun's energy in this way, corals are able to grow rapidly and form vast reef structures, but are constrained to live near the water surface (3).
While, on average, zooxanthellate coral can obtain around 70 percent of its nutrient requirements from zooxanthellae photosynthesis, the coral may also feed on zooplankton (5). The polyps' tentacles, which in this species are mostly extended at night, contain stinging cells called “nematocysts” that trap the drifting zooplankton, directing it into the central mouth, which also acts as an anus to excrete waste products after digestion (3) (5).
Barabattoia amicorum is capable of asexual reproduction, in which the colony proliferates through the production of clones that bud from the outer walls of the individual polyps, and by sexual reproduction, in which the polyps spawn large numbers of sperm and eggs. The fertilised eggs develop into planktonic larvae, which travel through the water column, before settling and metamorphosing into sessile polyps (3) (6).Top
Stony coral range
Mainly occurring in tropical waters, Barabattoia amicorum is widely distributed throughout the Indo-West Pacific (1). Populations also occur in the Red Sea (1) and may also be found in the Arabian Gulf (4).Top
Stony coral habitat
Barabattoia amicorum is found in shallow reef environments, especially on the rear side of reefs where the colonies are protected from strong wave action (3). It also occurs in lagoons, on areas of soft-substrate between reefs, and on sub-tidal rock to depths of at least 20 metres (1).Top
Stony coral statusTop
Stony coral threats
Around one third of the world's reef-building corals are threatened with extinction (7). The principal threat to corals is the rise in sea temperature associated with global climate change. This leads to coral bleaching, where the symbiotic algae are expelled, leaving the corals weak and vulnerable to an increasing variety of harmful diseases (1). Other harmful effects of climate change include more frequent destructive, extreme weather incidents, as well as increased ocean acidification, which impairs a coral's ability to form a skeleton. These global threats are compounded by localised threats from pollution, destructive fishing practices, invasive species and human development (1) (7). While Barabattoia amicorum is currently widespread, the multitude of threats faced by this species, means that its conservation status could rapidly change (1).Top
Stony coral conservation
Like all coral species, Barabattoia amicorum is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), which means that any international trade is strictly controlled by the use of permits and annual quotas (2). In addition, Barabattoia amicorum falls within several Marine Protected Areas across its range (1).
Specific conservation measures recommended for this species include carrying out extensive studies of its population, biology, and ecology, along with more research into existing and potential threats. In response to the threat of climate change, artificial propagation and preservation of sperm and eggs may become necessary to safeguard Barabattoia amicorum against complete extinction (1).Top
Find out more
To find out more about the conservation of coral reefs see:
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:
- Metabolic process characteristic of plants in which carbon dioxide is broken down, using energy from sunlight absorbed by the green pigment chlorophyll. Organic compounds are made and oxygen is given off as a by-product.
- Aquatic organisms that drift with water movements; may be either phytoplankton (plants), or zooplankton (animals).
- Permanently attached; not freely moving.
- Describing a relationship in which two organisms form a close association, the term is now usually used only for associations that benefit both organisms (a mutualism).
- Tiny aquatic animals that drift with currents or swim weakly in water.
IUCN Red List (December, 2008)
CITES (December, 2008)
- Veron, J.E.N. (2000) Corals of the World. Australian Institute of Marine Science, Townsville, Australia.
- Riegl, B. (1999) Corals in a non-reef setting in the southern Arabian Gulf (Dubai, UAE): fauna and community structure in response to recurring mass mortality. Coral Reefs, 18: 63 - 73.
- Barnes, R.S.K., Calow, P., Olive, P.J.W., Golding, D.W. and Spicer, J.I. (2001) The Invertebrates: A Synthesis, 3rd Edition. Blackwell Science, Oxford.
- Richmond, R.H. and Hunter, C.L. (1990) Reproduction and recruitment of corals: comparisons among the Caribbean, the Tropical Pacific, and the Red Sea. Marine Ecology Progress Series, 60: 185 - 203.
- Carpenter, KE et al. (2008) One-Third of Reef-Building Corals Face Elevated Extinction Risk from Climate Change and Local Impacts. Science, 321: 560 - 563.
More »Related species
Play the Team WILD game
This species is featured in:
This species is featured in Jewels of the UAE, which showcases biodiversity found in the United Arab Emirates in association with the Environment Agency – Abu Dhabi.
MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.
Terms and Conditions of Use of Materials
Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.
Visitors to this website (End Users) are entitled to:
- view the contents of, and Material on, the website;
- download and retain copies of the Material on their personal systems in digital form in low resolution for their own personal use;
- teachers, lecturers and students may incorporate the Material in their educational material (including, but not limited to, their lesson plans, presentations, worksheets and projects) in hard copy and digital format for use within a registered educational establishment, provided that the integrity of the Material is maintained and that copyright ownership and authorship is appropriately acknowledged by the End User.
End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.
Additional use of flagged material
Green flagged material
Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.
Creative commons material
Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.
Any other use
Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.
Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.