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Phylum Cnidaria > Class Anthozoa > Subclass Zoantharia/Hexacorallia > Order Scleractinia > Family Fungiidae
Feather mushroom coral
Ctenactis sp.*
Family Fungiidae
updated Nov 2019
Where seen? This oval mushroom coral with a feather-like texture is sometimes seen on some of our undisturbed Southern shores. The coral is free-living (it is not attached to the surface) and large ones may be seen on sandy shallow areas near living reefs.

Features: Oval or elongated convex disks with rounded ends, to about 20-30cm long. A prominent central furrow. Ctenactis echinata has one mouth, while the other species may have several. In all of them, the mouths are found only in the central furrow. Upper surface with thin lines radiating from the central furrow, so the entire animal resembles a feather. Lines are parallel, continuous with relatively large triangular, evenly spaced 'teeth' that are obvious even when covered with living tissue. The tentacles are tiny and very sparse. The underside usually concave, some with radiating lines of short bumps. Colours seen include yellow, brown, green and blue.

Sometimes confused with other long mushroom corals. Here's more on how to tell apart elongated mushroom hard corals.

Status and threats: Ctenactis albitentaculata is listed as globally Near Threatened by the IUCN.

Raffles Lighthouse, Jul 06

Large, triangular, evenly spaced 'teeth'.

Prominent central furrow.

Underside concave.

Underside and sides.

*Species are difficult to positively identify without close examination.
On this website, they are grouped by external features for convenience of display.

Feather mushroom corals on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores


Tanah Merah, May 14
Photo shared of Loh Kok Sheng on his blog.


Kusu Island, Jun 21
Photo shared of Richard Kuah on facebook.

St John's Island, Apr 16
Photo shared of Loh Kok Sheng on his blog.

St John's Island, Apr 21
Photo shared of Loh Kok Sheng on facebook.


Pulau Semakau (East), Dec 20
Photo shared of Loh Kok Sheng on facebook.

Terumbu Semakau, Apr 13
Photo shared of Loh Kok Sheng on flickr.


Terumbu Raya, Mar 16
Photo shared of Marcus Ng on facebook.

Terumbu Raya, May 10
Photo shared of Loh Kok Sheng on his flickr.

Beting Bemban Besar, Nov 14
Photo shared of Loh Kok Sheng on facebook.


Raffles Lighthouse, Aug 06

Underside.

Raffles Lighthouse, Jul 06

Mouth in the central furrow.

Terumbu Bemban, Jul 11

Tiny tentacles, very sparse.

Ctenactis species recorded for Singapore
from 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.
in red are those listed as threatened on the IUCN global list.

  Family Fungiidae
Genus Ctenactis
 

Ctenactis albitentaculata (Near Threatened)
Ctenactis crassa=Herpetoglossa simplex
Ctenactis echinata=Fungia echinata
**


Links

References

  • Hoeksema, Bert W. and Esther G. L. Koh. 30 Dec 2009. Depauration of the mushroom coral fauna (Fungiidae) of Singapore (1860s-2006) in changing reef conditions (pdf). Raffles Bulletin of Zoology Supplement No. 22: 91-101.
  • 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.
  • Erhardt, Harry and Daniel Knop. 2005. Corals: Indo-Pacific Field Guide IKAN-Unterwasserachiv, Frankfurt. 305 pp.
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