corallimorphs text index | photo index
Phylum Cnidaria > Class Anthozoa > Subclass Zoantharia/Hexacorallia > Order Corallimorpharia
Frilled corallimorph
Rhodactis inchoata
Family Discosomidae
updated Nov 2019

Where seen? This little animal with a delicate fringe around the edge of its disk-shaped body is sometimes encountered on our Southern shores, in coral rubble areas.

Features: Each polyp about 2-4cm in diameter, usually in small groups of 5-10, sometimes many more. When submerged, the expanded polyps may be crowded next to one another so that each forms folded polygonal shapes. So it is sometimes mistaken as a hard coral.

Cyrene Reef, Jun 08

Clusters of very short branched tentacles on the oral disk.

Short fine tentacles fringe the outer edge of the oral disk. On the disk itself, short, clusters of very short branched tentacles are arranged in rows radiating from the mouth in the centre. The mouth is usually held upturned and is then quite prominent.

The underside is smooth and brown. The animal can tuck its oral disk into the body column when it is exposed out of water. Seen in a wide range of colours: from pale to bright green to blue, also with brown tentacles.

St. John's Island, Aug 07

Oral disk edged with fine tentacles.

Oral disk tucked into the body column.

Sisters Island, Jan 06

Sisters Island, Feb 10

Pulau Jong, Jul 06

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

Frilled corallimorphs on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores

Labrador, Aug 17

Photo shared by Loh Kok Sheng on facebook.

Terumbu Hantu, Jun 16
Photo shared by Marcus Ng on facebook

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

Pulau Senang, Jun 10

Pulau Berkas, May 10

Terumbu Pempang Laut, Aug 21
Photo shared by Toh Chay Hoon on facebook.

Pulau Berkas, May 10


Terumbu Berkas, Jan 10


  • Corallimorpharia on The Biodiversity of Singapore website, Lee Kong Chian Natural History Museum.


  • Ren Min Oh, Mei Lin Neo, Nicholas Wei Liang Yap, Sudhanshi Sanjeev Jain, Ria Tan, Chaolun Allen Chen and Danwei Huang Citizen science meets integrated taxonomy to uncover the diversity and distribution of Corallimorpharia in Singapore, The Raffles Bulletin of Zoology Volume 67, Pp. 306-321.
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