Stony coral (Euphyllia glabrescens)

Euphyllia glabrescens with acoel flatworms on tentacles
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Stony coral fact file

Stony coral description

GenusEuphyllia (1)

Whilst most coral species are identified entirely by their skeletons, for Euphyllia species it is necessary to look at the living coral polyp to distinguish between different species (3). The coral polyp is basically an anemone-like animal that secretes a skeleton, and possesses tentacles, and polyps form colonies which join together at the base of their skeletons. Each of the 15 species of Euphyllia that are currently known has very differently shaped large and fleshy tentacles, which are extended during the day and night (3).


Stony coral biology

It is thought that the differences in the shape of tentacles between Euphyllia species may be related to specialised feeding habits (3). These tentacles, unlike many other corals, do not possess clusters of stinging cells, and so may be adapted to capture food particles using water and cilia (microscopic hair-like projections) (3). Euphyllia corals also possess specialised tentacles that extend further than the normal feeding tentacles. These ‘sweeper tentacles’, can extend up to eight inches further than the normal tentacles and have numerous powerful stinging cells (nematocysts), that can cause significant localised damage to other corals that are growing nearby (5). On reefs where there is fierce competition for space, this is an extremely good defensive adaptation to possess.

Euphyllia corals have separate male and female colonies (not all corals do), and most release eggs and sperm for external fertilization in the water, which then form larvae. In equatorial localities however, some may brood larvae internally (3). In captivity, asexual reproduction is much more common (5).


Stony coral range

Occurs in the Indian and Pacific Oceans, from Mozambique, up to the Red Sea, to southern Japan, northern Australia and the Fiji Islands (4).

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Stony coral habitat

Euphyllia corals occur in a wide range of reef environments; particularly shallow reefs (4).


Stony coral status

Classified as Near Threatened (NT) on the IUCN Red List (1) and listed on Appendix II of CITES (2).

IUCN Red List species status – Near Threatened


Stony coral threats

Euphyllia corals face the many threats that are impacting coral reefs globally. It is estimated that 20 percent of the world’s coral reefs have already been effectively destroyed and show no immediate prospects of recovery, and 24 percent of the world’s reefs are under imminent risk of collapse due to human pressures. These human impacts include poor land management practices that are releasing more sediment, nutrients and pollutants into the oceans and stressing the fragile reef ecosystem. Over fishing has ‘knock-on’ effects that results in the increase of macro-algae that can out-compete and smother corals, and fishing using destructive methods physically devastates the reef. A further potential threat is the increase of coral bleaching events, as a result of global climate change (6). A more specific potential threat to Euphyllia corals is harvesting. Its colourful fleshy tentacles make it a desirable species for aquariums, and is therefore one of the species that dominates the live coral trade (7).


Stony coral conservation

Euphyllia 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 (2). Indonesia has a quota system for corals, monitored though CITES. The aim of the quotas are to ensure harvest are kept at a sustainable level, but in reality, they are hard to set at the right level due to a lack of knowledge regarding coral biology. In 1999 the European Union CITES Scientific Review Group considered that some of the Indonesian quotas were too high and placed a ban on the import of E. divisa and E. glabrescens, and then in 2000 extended this trade suspension to all Euphyllia species (8) (9). Euphyllia corals will form part of the marine community in many marine protected areas (MPAs), which offer coral reefs a degree of protection, and there are many calls from non-governmental organisations for larger MPAs to ensure the persistence of these unique and fascinating ecosystems (6).

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

Find out more

For further information on this species see:

  • Veron, J.E.N. (2000) Corals of the World Vol. 2. Australian Institute of Marine Science, Townsville, Australia.

For further information on 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:



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


  1. IUCN Red List (October, 2009)
  2. CITES (October, 2009)
  3. Veron, J.E.N. (1986) Corals of Australia and the Indo-Pacific. Angus and Robertson Publishers, UK.
  4. Veron, J.E.N. (2000) Corals of the World. Vol. 2. Australian Institute of Marine Sciences, Townsville, Australia.
  5. Borneman, E. (1997) Sweeping beauty: a tale of anchors, hammers and other things. Aquarium Net, January Issue. Available at:
  6. Wilkinson, C. (2004) Status of Coral Reefs of the World. Australian Institute of Marine Science, Townsville, Australia.
  7. Green, E. and Shirley, F. (1999) The Global Trade in Corals. World Conservation Press, Cambridge, UK.
  8. Wabnitz, C., Taylor, M., Green, E. and Razak, T. (2003) From Ocean to Aquarium. UNEP-WCMC, Cambridge, UK.
  9. Wood, E. (2001) Global advances in conservation and management of marine ornamental resources. Aquarium Sciences and Conservation, 3: 65 - 77.

Image credit

Euphyllia glabrescens with acoel flatworms on tentacles  
Euphyllia glabrescens with acoel flatworms on tentacles

© Doug Perrine /

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