Plesiastrea versipora
(Plesiastrea versipora)
LC
Overview
Plesiastrea versipora is distributed extensively across the Indo-Pacific and found in a number of high latitude, cooler water habitats. It can be found in a wide range of reef environments and rocky foreshores, adapting its growth form depending on conditions. Commonly green or brown in colour Plesiastrea versipora can grow up to 3 meters in diameter and its tentacles grow in two different sizes. The primary threats to this species include ocean acidification, coral bleaching, over-fishing, sedimentation and pollution.
Urgent Conservation Actions
More research into the ecology of this species is required.
Distribution
Red Sea, Gulf of Aden, Indian Ocean, Pacific Ocean.
Media from ARKive
ARKive image - A small knob coral colony
ARKive image - Small knob coral colony with polyps extended
ARKive image - Small knob coral colony
ARKive image - Many small knob coral colonies around a sponge
ARKive image - A small knob coral colony showing signs of bleaching
Evolutionary Distinctiveness
Order: Scleractinia
Family: Faviidae
Plesiastrea versipora traditionally belongs to the large and diverse Faviidae family however more recent mitochondrial analysis of this genus by Fukami (????) places Plesiastrea versipora in a new clade (XIV) with the Physogyra, Plerogyra and Blastomussa genera. The earliest fossil records of the Plesiastrea genus date back to the Miocene period which occurred between 5.2 and 24 millions years ago.
Description
Size: 
Up to 3m in diameter
Plesiastrea versipora is a colonial species which grows in a plate like form on reef slopes where light intensity is low, and in more rounded colonies in shallow areas where light intensity is higher. Corallites are 2-4 mm in diameter and are circular in shape with space between each one. Colonies growing in the tropics tend to be paler in colour than those that grow in cooler, high latitude areas; colours vary between yellow, cream, green or brown. Short tentacles which grow in two alternate sizes are sometimes extended during the day.
Ecology

Plesiastrea versipora is a zooxanthellate coral which means that it obtains some of its nutrition from single celled algae called zooxanthellae living in its tissue. These zooxanthellae require sunlight for photosynthesis so Plesiastrea versipora is largely restricted to habitats where there is light availability. However Plesiastrea versipora is not entirely dependent on zooxanthellae for nutrition as the tentacles of this species are able to catch plankton. The tips of the tentacles which are located around the edges of the corallite wall contain stinging cells (nematocysts) that stun plankton and allow the tentacles to take hold of the prey and pass it to the mouth of the corallite.

The growth form of a colony of Plesiastrea versipora can depend on the location and habitat in which it grows. Colonies at high latitudes grow larger than those found in the tropics and colonies in shallow, exposed areas are more rounded in shape compared to flatter, plate like colonies found in habitats where the light intensity is low. The ability of Plesiastrea versipora to grow even at cooler temperatures in high latitude is an ecological trait that distinguishes this species from many others.

Plesiastrea versipora is a broadcast spawning species which means it reproduces by releasing large numbers of eggs and sperm into the water column where they will become fertilised. Many species of coral are known to spawn synchronously at certain times of the year, often following a lunar cycle. The fertilised eggs develop into planulae and travel in the water column until they settle onto a suitable substrate and develop into a polyp. This polyp is then able to reproduce asexually through a process known as budding. Plesiastrea versipora grows though extratentacular budding where new polyps develop on the side of a parent polyp and pinch off to form a new polyp.

Habitat
Plesiastrea versipora is found in most reef habitats but especially in shaded places such as overhangs. It is also found on rocky foreshores of temperate locations, subtidal rocky reefs, reef slopes and lagoons. Plesiastrea versipora is most commonly found between depths of 12-15m, however it can be found at all depths down to 40m.
Distribution
Plesiastrea versipora has a very wide distribution across the Indian and Pacific Oceans. This species is extensively distributed in the Indian Ocean along the coast of East Africa, the Red Sea, Gulf of Aden, India, Sri Lanka and numerous Indian Ocean islands.

In the Pacific Ocean this Plesiastrea versipora is extensively distributed across Asia including China and Japan, Australasia and many of the Pacific Ocean Islands including the Cook Islands and French Polynesia.
Population Estimate
There is no species specific population estimate for Plesiastrea versipora.
Population Trend

The population of Plesiastrea versipora is declining.

The percentage of live coral cover is decreasing across the world. 19% of the worlds corals reefs have already been effectively lost and this trend looks set to continue.

Status
Least Concern (LC) 2010.4 IUCN Red List of Threatened Species
Threats

There are a number of threats to the population of Plesiastrea versipora. Ocean acidification is a result of the increasing levels of carbon emissions produced by human activities. Carbon dioxide (CO2) naturally dissolves in sea water but as carbon dioxide levels in the atmosphere continue to increase, more CO2 is dissolving into the water, disrupting the normal chemical balance and altering the pH of the water. This pH change affects the calcium carbonate skeletons of coral by making them more brittle and slower to grow. If CO2 levels in the atmosphere continue to increase the pH of the ocean will continue to decrease and if this change continues at the current rate then by 2040 the coral reefs of the world could be in an irreversible decline.

Human activities are threatening coral species such as Plesiastrea versipora in additional ways. The growing human population in all areas of the world is placing greater pressure on marine resources such as fish for food and the conversion of coastal habitats, such as mangroves, for residential and industrial use. Overfishing and the destructive techniques such as dynamite, poison and trawling cause direct physical damage to the reef and reduce the number of herbivorous fish that traditionally control the growth of algae. Without herbivorous fish a coral reef can quickly become dominated by algae in a process known as an algae phase shift that reduces light and oxygen availability and places stress on the coral.

Stress is also placed onto coral by sedimentation and pollution which are the results of habitat destruction and coastal development. As coastal areas are developed, sediment and pollution is washed onto the reef reducing light availability and water quality. Sediment, such as soil, can settle onto coral and smother it to death if the coral is unable to remove it. The stress caused by algae phase shifts, sedimentation and pollution also make corals more susceptible to diseases and bleaching.

Coral bleaching is the expulsion of symbiotic zooxanthellae from the tissue of the coral and is a response to stressful conditions such as temperature extremes or pollution. Thermally induced bleaching is occurring more frequently as sea temperatures increase as the global climate changes. Although it is not known how susceptible Plesiastrea versipora is to thermally induced coral bleaching, it is a threat that has to be taken seriously as the climate continues to change.

Conservation Underway
Plesiastrea versipora is protected by CITES Appendix II which regulates the global export of threatened species.

There are no other specific conservation measures in place for Plesiastrea versipora however due its large range it is likely that is species is located within one of a number of marine protected areas (MPAs) that are located in the Indian and Pacific Oceans. The largest of these MPAs is the Chagos Marine Protected Area which protects 545,000 sq km of marine and terrestrial habitats in the British Indian Ocean Territory.

There are also a number of ambitious conservation initiatives in place in the Indian and Pacific Oceans. The Micronesia Challenge was launched in 2006 and five Micronesian governments including the Federated States of Micronesia, the Republic of the Marshall Islands, the Republic of Palau, the U.S. Territory of Guam and the Commonwealth of the Northern Mariana Islands have committed to effectively conserve at least 30% of their near shore marine resources. MPAs and conservation networks have already been set up to help achieve this commitment.

In the Pacific Islands, conservation is lead by CRISP (Initiative for the Protection and Management of Coral Reefs in the Pacific). This project is developing ways to protect the future of coral reefs and the communities that depend on them by conserving biodiversity and developing economic and environmental services.
Conservation Proposed
Conservation in the western Indian Ocean needs to be developed further and the threat of over-fishing and destructive fishing techniques needs to be addressed more vigorously. Expansion of the current network of MPAs is recommend in all regions as less than 2% of coral reefs are currently located with MPAs.

Additional research into the ecology and life history would allow a better understanding of this species and the conservation measures needed to protect it from further populations decline.
Links
References

DeVantier, L., Hodgson, G., Huang, D., Johan, O., Licuanan, A., Obura, D., Sheppard, C., Syahrir, M. & Turak, E. 2008. Plesiastrea versipora. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. <www.iucnredlist.org>. Downloaded on 31 December 2010.

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

Mora, C. et al. 2006. Coral Reefs and the Global Network of Marine Protected Areas. Ecology 312:1750-1751

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.

Veron J.E.N. 2000. Corals of the World. Volume 2. Townsville. Australian Institute of Marine Science

Veron, J.E.N. et al. 2009. The coral reef crises: The critical importance of <350 ppm CO2. Mar Pollut Bull. 58:1428-1436

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

 

Distribution map based on data provided by the IUCN Spatial Data Collection.

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