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Phylum Cnidaria > Class Anthozoa > Subclass Zoantharia/Hexacorallia > Order Scleractinia > Family Acroporidae
Acropora corals
Acropora sp.

Family Acroporidae
updated May 13
Where seen? These corals can form delicate colonies that resemble miniature underwater forests. They are always a delight to encounter. Sometimes seen on many of our Southern shores, larger colonies are more commonly seen on undisturbed and remote reefs. The genus Acropora has the largest number of species of all the hard corals. The scientific name is usually pronounced as 'ah-crop-or-ah'.

Features: Colonies seen usually 15-20cm, but on undisturbed shores can be 50cm or larger. Many grow into branching forms that give rise to common names like 'staghorn coral'. For some, the entire colony often has a flat top so they are sometimes also called 'table-top' or 'table coral'. Others appear bushy. Branches are generally cylindrical with corallites appearing all around the branch.

Corallite tiny (0.5cm) smooth cups or tubes. Acropora corals have a distinctive corallite, usually at the tip of the branch, that is larger than the other corallites. This is called an axial corallite. New corallites (called secondary or radial corallites) bud off along the sides while the axial corallite continues to grow upwards on the tip of the branch. The axial corallite lacks zooxanthellae but grows rapidly as it is fed by other areas of the colony. The tips are often white or brightly coloured.

Polyps tiny (0.2-0.5cm), with long tapering tentacles. When fully extended, the colony can appear 'furry'.

Sometimes mistaken for branching pocilloporid corals (Family Pocilloporidae).

There are probably several different species on these pages. It's hard to distinguish them without close examination of small features. On this website, they are grouped by large external features for convenience of display.

As a group, acropora corals are adaptable and found in a wide range of habitats from murky waters to wave-pounded areas and some can survive regular exposure at low tide. These protect themselves with a thick mucus coat and UV-absorbing substances. They come in a wide variety of colours.

Some acropora corals are rather delicate and will shatter if they are knocked against. So please do not touch them, in fact, we should not touch any living hard corals.

Role in the habitat: Acropora corals are among the important building blocks of a reef. Together with Montipora species, also members of the Family Acroporidae, acropora corals account for one-third of reef-building coral species. Acropora corals include some of the fastest growing hard corals. Their branching forms provide shelter to a wide variety of animals, from small fishes to tiny clams, small crabs to shrimps.

Human uses: Acropora corals are popular in the live aquarium trade and wild colonies are often taken from the natural reefs to supply this demand. Efforts to breed and raise acropora corals have been successful and it is hoped this supply will reduce collection from the wild. Although captive bred acropora corals are healthier and easier to care for than wild collected specimens, captive bred corals are more expensive.

Status and threats: Some of our Acropora corals are listed as threatened on the IUCN global listing. Like other creatures of the intertidal zone, they are affected by human activities such as reclamation and pollution. Trampling by careless visitors, and over-collection by hobbyists also have an impact on local populations.

Some acropora coral form table-like colonies.
Raffles Lighthouse, Jun 07


Corallites with tentacles contracted.
Sisters Island, Dec 05



With the tentacles extended,
the colony can appear 'furry'.
Pulau Semakau, Apr 08


Producing mucus to protect themselves.
Pulau Semakau, Mar 05
Coral scallop
Sisters Island, May 08

Machine gun shrimp
Kusu Island, Jun 10
Photo shared by Loh Kok Sheng on his blog.

Bandit coral crab
Sisters Islands, Mar 06

Acropora goby
Sisters Islands, Dec 05



Acropora coral @ Pulau Hantu 17Apr2010 from SgBeachBum on Vimeo.


Elegant acropora coral (Acropora sp.)

Acropora species recorded for Singapore
Danwei Huang, Karenne P. P. Tun, L. M Chou and Peter A. Todd. 30 Dec 2009. An inventory of zooxanthellate sclerectinian corals in Singapore including 33 new records **the species found on many shores in Danwei's paper.
*Groups based on in Veron, Jen. 2000. Corals of the World.
in red are those listed as threatened on the IUCN global list.

  Acropora corals seen awaiting identification
Species are difficult to positively identify without close examination with a microscope. On this website, they are grouped by external features for convenience of display.
  Elegant acropora
Pinecone acropora
Staghorn acropora
Stumpy acropora
Tubular acropora

  Family Acroporidae
Genus Acropora*
  Group 6: Large staghorn-like
Acropora grandis
Acropora muricata=Acropora formosa
(Staghorn coral) (Near Threatened)

Group 7: Large encrusting or horizontally branching species with rasp-like radial corallites
Acropora abrotanoides/danai
Acropora intermedia=Acropora nobilis
Acropora palmerae
(Vulnerable)
Acropora robusta

Group 8: Large horizontally branching with upturned branch ends
Acropora acuminata
(Vulnerable)
Acropora donei
(Vulnerable)
Acropora valenciennesi

Group 9: Interlocking basal branches and sharp edged radial corallites
Acropora divaricata
(Near Threatened)
Acropora solitaryensis
(Vulnerable)

Group 10: Interlocking basal branches and rounded radial corallites
Acropora glauca
(Near Threatened)

Group 11: Conspicuous secondary branches and smooth edged corallites
Acropora austera
(Near Threatened)
Acropora florida
(Near Threatened)
Acropora lutkeni
(Near Threatened)

Group 12: Small, stag-horn like
Acropora microphthalma

Group 14: Middle-sized branches and irregular radial corallites
Acropora horrida
(Vulnerable)

Group 19: Tables with fine horizontal branches
Acropora cytherea
Acropora hyacinthus
(Near Threatened)
Acropora spicifera
(Vulnerable)

Group 21: Digitate clumps with finger-like branches
Acropora humilis
(Near Threatened)
Acropora samoensis**

Group 22: Digitate plates with small branchlets
Acropora dendrum
(Vulnerable)
Acropora digitifera**
(Near Threatened)

Group 24: Digitate clumps with spiny corallites
Acropora polystoma
(Vulnerable)

Group 26: Branching with scale-like radial corallites
Acropora aspera
(Vulnerable)
Acropora nana
(Near Threatened)
Acropora pulchra

Group 27: Corymbose clumps with short thin branchlets and appressed radial corallites
Acropora latistella
Acropora subulata

Group 28: Corymbose clumps with diverging horizontal branches and small radial corallites
Acropora aculeus**
(Vulnerable)

Group 29: Corymbose clumps within thin branchlets and radial corallites with flaring lips
Acropora selago
(Near Threatened)
Acropora tenuis
(Near Threatened)

Group 30: Corymbose plates with short compact branchlets and variable radial corallites
Acropora anthocercis
(Vulnerable)
Acropora willisae
(Vulnerable)


Group 31: Corymbose bushes or plates with elongate tubular axial corallites
Acropora granulosa
(Near Threatened)

Group 32: Corymbose bushes with conspicuous rounded corallites
Acropora loripes
(Near Threatened)
Acropora verweyi
(Vulnerable)

Group 33: Bushes with irregular smooth edged radial corallites
Acropora secale
(Near Threatened)

Group 34: Bushes with sharp edged radial corallites
Acropora cerealis
Acropora nasuta
(Near Threatened)

Group 35: Bushes with appressed radial corallites
Acropora valida**

Group 38: Bottlebrush colonies
Acropora elseyi
Acropora longicyathus
Acropora subglabra

Links

References

  • Danwei Huang, Karenne P. P. Tun, L. M Chou and Peter A. Todd. 30 Dec 2009. An inventory of zooxanthellate sclerectinian corals in Singapore including 33 new records (pdf). Raffles Bulletin of Zoology Supplement No. 22: 69-80.
  • Veron, Jen. 2000. Corals of the World Australian Institute of Marine Science, Australia. 3 volumes.
  • Chou, L. M., 1998. A Guide to the Coral Reef Life of Singapore. Singapore Science Centre. 128 pages.
  • Erhardt, Harry and Daniel Knop. 2005. Corals: Indo-Pacific Field Guide IKAN-Unterwasserachiv, Frankfurt. 305 pp.
  • Borneman, Eric H. 2001. Aquarium Corals: Selection, Husbandry and Natural History T.F. H Publications. 464 pp
  • Wee Y.C. and Peter K. L. Ng. 1994. A First Look at Biodiversity in Singapore. National Council on the Environment. 163pp.
  • Davison, G.W. H. and P. K. L. Ng and Ho Hua Chew, 2008. The Singapore Red Data Book: Threatened plants and animals of Singapore. Nature Society (Singapore). 285 pp.
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