Thursday, March 30, 2017

Acanthastrea


Family Mussidae

Welcome to the Acanthastrea genus landing page. In this section, you will find general information about this genus and tips on how to identify it. If you are looking to confirm an observation made with the Coral Finder, use the image browser below to view some of the variation possible in Acanthastrea. Comparison with similar genera can be made further down the page: Favites, Favia, or Moseleya.


Vital Statistics

  • 12 species
  • Coral Finder p. 9c, 14c, 15
  • COTW – Vol 3 p.12-31

Distribution

Found throughout the Indo-Pacific.

ID Tips

Acanthastrea colonies tend to be thick encrusting or massive and can be found across all reef zones. They are generally uncommon.

Underwater, the distinctive features of this genus are the tall spiky toothed septa which can be felt or seen through the thick fleshy tissue, a feature common to all members of the family Mussidae. The corallites can be rounded, angular, and sometimes elongated. Corallites are usually cerioid (common walls) but can sometimes be subplocoid (walls separated to a degree). The fleshy tissue that characterises this genus can often mask the exact nature of the corallite walls.

Note the spikey teeth on the septa. See how they can be seen through the tissue.
Learn to recognise the distinctive fleshy carpet-like tissue of Acanthastrea which sometimes hides the septal teeth.

Similar genera to Acanthastrea (Coral Finder p15)

The Coral Finder lists Acanthastrea in one key group with Favites and Moseleya being candidates for confusion. Some species of Acanthastrea can also appear like Favia when the corallite walls become separated (see below). Large species of Acanthastrea may appear like the genus Lobophyllia which shares the fleshy tissue and large teeth of the family Mussidae. Close inspection (with tissue retracted) shows Lobophyllia to have meandering corallites with separate walls on tall stems (phaceloid). Acanthastrea forms massive / thick encrusting colonies with corallites that generally share the wall.

Comparing Acanthastrea with Favites

Acanthastrea are generally easily recognised by the distinctive fleshy polyps and tall spikey septal teeth typical of the family Mussidae. However, some species of Acanthastrea can appear somewhat  Favites / Favia-like – see examples below. Tip: when confronted by a “strange” Favites / Favia colonies keep Acanthastrea in the back of your mind! Learn to see the ragged, fleshy “look” caused by the tall septa pushing through the thick Mussid tissue.

Acanthastrea echinata
Favites complanata
Favites russelli

Comparing Acanthastrea with Favia

Some species of Acanthastrea are quite variable and can have corallites with separate walls (sub-plocoid) becoming Favia-like. The high spines / teeth near the corallite mouth of the Acanthastrea echinata colony below are the clue to its Mussid family heritage.

Acanthastrea echinata

Favia maritima

Comparing Acanthastrea with Moseleya

Moseleya latistellata is rare but can look like Acanthastrea. It has finer, less noticeable septal teeth, less fleshy tissue, and in larger colonies, an enlarged central corallite surrounded by daughter corallites.

Moseleya latistellata

Ecology

Taxonomic Changes

Learning Resources

Coral Hub

  • Mussidae family page

Links

Suggested Reading – Identification Tools

  • Budd, A. F., & Stolarski, J. (2009). Searching for new morphological characters in the systematics of scleractinian reef corals: comparison of septal teeth and granules between Atlantic and Pacific Mussidae. Acta Zoologica, 90(2), 142-165.
  • Chevalier, J. P. (1975). Les scleractiniaires de la Melanesie Francaise.  II Expedition Francaise sur les recifs coralliens de la Nouvelle-Caledonie. Paris: Singer-Polignac.
  • Davie, P. J., & Phillips, J. A. (2009). 13th International Marine Biological Workshop, The Marine Fauna and Flora of Moreton Bay, Queensland. Memoirs of the Queensland Museum, 54(2), 1-118.
  • Sheppard, C. R. C., & Salm, R. V. (1988). Reef and coral communities of Oman, with description of a new coral species (Order Scleractinia, Genus Acanthastrea). Journal of Natural History, 22(1), 263-279.
  • Veron, J. E. N. (1985). Corals of Australia and the Indo-Pacific. Sydney: Angus and Robertson.
  • Veron, J. E. N. (2000). Corals of the World. Melbourne: Australian Institute of Marine Science.
  • Veron, J. E. N. (2002). New species described in ‘Corals of the World: Australian Institute of Marine Science.
  • Veron, J. E. N., & Pichon, M. (1980). Scleractinia of Eastern Australia.  Part 3, Families Agaraciidae, Siderastreidae, Fungiidae, Oculinidae, Merulinidae, Mussidae, Pectiniidae, Carophylliidae, Dendrophylliidae. Australian Institute of Marine Science Monograph Series, IV, 471.

Suggested Reading – Other Topics