Pillar Coral
(Dendrogyra cylindrus)
VU
Overview
Colonies of this species are found in flat, sheltered locations ranging from the southern tip of Florida down to Venezuala and Panama. The pillar coral possesses one of the most distinct morphologies of any coral species, with colonies forming several enormous spires that may reach 2 metres in height. These large colonies are typically grey or brown in colour and have a hairy appearance when polyps are extended. Despite being offered protection through a number of marine protected areas (MPAs) this species is threatened by global pressures such as climate change and ocean acidification. As the only member of its genus, the Pillar coral has a high level of evolutionary distinctiveness.
Urgent Conservation Actions
A decision to protect this species under the Endangered Species Act (USA) is pending and if granted will offer the species additional conservation and protection. The species also resides within effective MPAs such as Florida Keys.
Distribution
This species is found in numerous coastal regions along the Western Atlantic.

 
Fact
Dendrogyra cylindrus can grow up to 2 meters in height!
Associated Blog Posts
2nd Aug 13
The month of July marked the 40th year of independence for the Bahamas and although I am too young to be one of those Bahamians who remember that 10th day of...  Read

3rd Apr 13
Nikita is one of our newest EDGE Fellows. As she explain in this blog, her commitment to the conservation of marine biodiversity in The Bahamas goes back to...  Read

Media from ARKive
ARKive image - Pillar coral, <i>Dendrogyra cylindrus</i> with fish in background
ARKive image - Pillar coral, <i>Dendrogyra cylindrus</i>
ARKive image - Pillar coral, <i>Dendrogyra cylindrus</i>
ARKive image - Pillar coral, <i>Dendrogyra cylindrus</i>
ARKive image - Pillar coral, <i>Dendrogyra cylindrus</i>, close up
ARKive image - Pillar coral, <i>Dendrogyra cylindrus</i>
Evolutionary Distinctiveness
Order: Scleractinia
Family: Meandrinidae
Dendrogyra cylindrus belongs to an evolutionarily distinct genus, and its family, Meandrinidae, consists of just 10 species. This genus is monospecific meaning this species is the only member of its genus. It retains a high level of evolutionary distinctiveness.

 
Description
Size: 
May reach 2 metres in height
Colonies of this species grow in tall cylindrical columns of heights up to 2m lending it a distinctive pillar-like appearance which gives rise to the species common name of Pillar coral.  The species hairy appearance is due to its tentacles which are normally extended throughout the day. Dendrogyra cylindrus colonies are grey-brown or olive in colour, and the corallites are arranged side by side with the mouths of the corallite aligned in the valleys.
Ecology
An overview of hard coral ecology can be found here.

As a zooxanthellate species this coral obtains a subset of its energy requirements from a symbiotic relationship with algae called zooxanthellae. Zooxanthellae live in the tissue of their host corals and require sunlight for photosynthesis, a process that supplies energy for the algae and its host coral.

It is a stony coral species meaning that as the individual animals (polyps) of this species grow, they exude calcium carbonate to form exoskeletons (corallites) for protection. Over time, the accumulation of calcium carbonate skeletons results in the formation of reefs. Specific oceanic conditions are required for polyps to synthesize and exude calcium carbonate.

The Pillar coral can reproduce both sexually and asexually. Sexual reproduction occurs through colonies releasing eggs or sperm into the water where fertilization takes place. Dendrogyra cylindrus individuals are either male or female (gonochoric) and release only the corresponding gamete (sperm in males, eggs in females) for reproduction. Spawning of sperm and eggs is usually synchronised between colonies to ensure the greatest chance of successful fertilization.  Survivorship of juvenile larvae is thought to be low due to the number of pressures such as predation, and competition for light and space. Asexual reproduction occurs by fragmentation when a pillar breaks off the main structure and new pillars grow up from the fallen one.
Habitat
Found in flat or gentle sloping reefs within more sheltered locations. Most commonly found at depths of 5-15m although they can survive at depths down to 25m.
Distribution
This species is found within the southern Gulf of Mexico, the vast majority of coastline in the Caribbean Sea and in the West Atlantic Ocean from Florida in the north to Venezuela in the south.
Population Estimate
No population estimate has been made for this species.
Population Trend
As of 2008 the IUCN has rated the population of the Pillar coral as stable. Nonetheless it is possible this species is undergoing some sort of decline. Currently, more than 75% of the reefs in the Caribbean are threatened and historically 80% of reefs in the region have been lost. It is unlikely that this continuing degradation is not affecting the Pillar coral population.
Status
Vulnerable (VU) 2012.2 IUCN Red List
Threats
Dendrogyra cylindrus is particularly susceptible to White plague type II disease. This disease is caused by bacteria and reveals itself as a sharp line of white exposed skeleton next to healthy tissue. This disease can progress quickly, spreading 1-2cm per day. Infection of coral appears to increase following disturbances such as destructive weather and coral bleaching, it is thought this is due to the increased stress of these events weakening the corals immune systems. 

In addition to coral bleaching, the frequency and intensity of storms is increasing as the global climate changes. Florida, the Gulf of Mexico and the Caribbean, where this species occurs, have all been subject to several destructive storms that can cause structural damage to the reefs and the pillar like structures of Dendrogyra cylindrus are particularly vulnerable. If these storms increase in frequency, as predicted over the next few decades, there will be less time for reefs to recover from the damage in between storm events.

A direct human impact within Dendrogyra cylindrus’ range is increased coastal development as a result of continued human population growth and a demand for tourism. Coastal development can lead to threats such as the run-off of waste water and sewage into the ocean and sedimentation which can decrease light penetration through the water column, reducing photosynthesis and subsequent coral growth. Sediment can also smother corals when it settles resulting in anoxic conditions which can be fatal. 

Another serious threat in many countries in the Caribbean region is over-fishing. This can lead to an algal phase shift, where algae replace coral as the dominant benthic taxa on the reef as a result of a reduction in the number of herbivorous fish that normally feed on the algae. The threat of over-fishing was particularly highlighted in 1983/1984 when there was a massive die-off the long spined sea urchin, Diadema antillarum in the Caribbean.  The return of Diadema antillarum to the reef not only aids the reversal of a phase shift but also benefits the recruitment and growth of coral species.

 
Conservation Underway
All coral species are listed on CITES Appendix II which regulates the export of threatened species.

It is also illegal to harvest corals for commercial purposes in US waters. Whilst a reasonably high proportion of Caribbean reefs lie within MPAs (30%), only 6% of these are considered fully effective. Meanwhile 40% were classified as ineffective as of 2011.

In 2008 a regional initiative named the Caribbean Challenge was implemented. The eight countries involved in this program have pledged to effectively manage and protect 20% of their coastal areas by 2020 and will do this by creating networks of marine protected areas (MPAs). The challenge also provides a trust fund to be used for MPA management, expansion and scientific monitoring.
Projects

This project supports in-country EDGE Fellows to help conserve relevant EDGE species

The project aims to quantify threats and determine the historical and present distribution of Dendrogyra cylindrus throughout The Bahamas. This project will raise awareness about coral reefs using Dendrogyra cylindrus as a flagship species while engaging youth from underserved communities in citizen science.

Conservation Proposed
A number of coral species residing in US waters, the Pillar coral being one, have recently been subject to status reviews. As a result there are proposals by the NOAA to upgrade the threat status of this species to endangered, a reclassification that will afford it additional conservation attention. The outcome of this review will be determined in late 2013.

This species is better researched than many due to its prominence and location in US waters. Nonetheless the species would benefit from further research into all aspects of its ecology and conservation in order to guide conservation proposals.

Continued designation and effective management of Marine Protected Area’s will also benefit coral species.

Finally, more must also be done to curb global emissions of greenhouse gases in order to prevent climate change and ocean acidification.
Associated EDGE Community members

NGO dedicated to working with local communities to conserve threatened marine environments.

A Marine Biologist with a passion for education and adventure, Nikita is studying EDGE Corals.

Francoise is working on EDGE corals in Los Roques, Venezuela

Links
References

Brandt, M.E. and McManus, J.W. (2009) Disease incidence is related to bleaching extent in reef-building corals. Ecology 90(10):2859-2867.

Bruckner, A.W. and Bruckner, R.J. (1997) Outbreak of coral disease in Puerto Rico.Coral reefs 16:4:260.

Department of Commerce. National Oceanic and Atmospheric Administration. Endangered and Threatened Wildlife and Plants:  Proposed Listing Determinations for 82 Reefbuilding Coral Species; Proposed Reclassification of Acropora palmata and Acropora cervicornis from Threatened to Endangered. Accessed: on 07 December 2012.

Fukami, H., Chen, C.A., Budd, A.F., Collins, A. Wallace, C. Et al. 2008. Mitochondrial and Nuclear Genes Suggest that Stony Corals are Monophyletic but Most Families of Stony Corals Are Not (Order Scleractinia, Class Anthozoa, Phylum Cnidaria). PLoS ONE 3(9):e3222. Doi:10.1371/journal.pone.0003222.

Gardner, T.A. et al. (2003) Long-Term Region-Wide Declines in Caribbean Corals.Science301:958-960.

Gastineau, G. and Soden, B. J. 2009. Model projected changes of extreme wind events in response to global warming. Geophysical Research Letters. 36.

Idjadi, J.A. et al. (2010) Recovery of the sea urchin Diadema antillarum promotes scleractinian coral growth on shallow Jamaica reefs. Mar. Eco. Pro. Ser.403:91-100.

Lewis, J.B. and Price, W.S. (1975) Feeding mechanisms and feeding strategies of Atlantic reef corals. J.Zool.,Lond.176:527-544.

National Oceanic and Atmospheric Administration. Coral Status Review Western Atlantic.  Accessed 04 Decmber 2012.

Secretariat of the Convention on Biological Diversity (2009). Scientific Synthesis of the Impacts of Ocean Acidification on Marine Biodiversity. Montreal, Technical Series No. 46, 61 pages.

Sutherland, K.P., Porter, J.W. and Torres, C. (2004) Disease and immunity in Caribbean and Indo-Pacific zooxanthellate corals. Mar.Eco.Pro.Ser. 266:273-302.

Toropova, C., Meliane, I., Laffoley, D., Matthews, E. and Spalding, M. (eds.) (2010).Global Ocean Protection: Present Status and Future Possibilities. Brest, France: Agence des aires marines protégées, Gland, Switzerland, Washington, DC and New York, USA: IUCN WCPA, Cambridge, UK : UNEP-WCMC, Arlington, USA: TNC, Tokyo, Japan: UNU, New York, USA:WCS. 96pp.

Wilkinson, C. 2008. Status of coral reefs of the world: 2008. Global Coral Reef Monitoring Network and Center, Townsville, Australia.

if you can provide new information to update this species account or to correct any errors, please email us at info@edgeofexistence.org


Forum comments

There are as yet no comments for this species.

Add a comment

You must log in to post. If you don't have a login, it's easy to register.