hard corals text index | photo index
Phylum Cnidaria > Class Anthozoa > Subclass Zoantharia/Hexacorallia > Order Scleractinia > Family Agariciidae
Castle coral
Pachyseris rugosa*
Family Agariciidae
updated Nov 2019
Where seen? This crumpled-looking coral is rarely seen, usually on our undisturbed Southern shores among living corals. 'Pachys' means 'thick' while 'seris' means 'lettuce-like'. 'Rugosa' means 'wrinkled'.

Features: Colony (10-30cm across) forming plates that may be encrusting or upright shapes, often irregular and contorted. The surface has short ridges that form maze-like patterns, perpendicular to the edge of the colony. There is a texture of fine lines perpendicular to these ridges. Colours seen include brown, green and blue.

Sometimes confused with other leafy hard corals like Lettuce coral (Pavona sp.).

Status and threats: This coral is listed as globally Vulnerable by the IUCN.

Terumbu Bemban, Jul 11
Fine lines perpendicular to thick ridges.

Terumbu Bemban, Jul 11

St. John's Island, Aug 08

Maze-like pattern.

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

Castle corals on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores

St. John's Island, May 10
Photo shared by Loh Kok Sheng on his blog.

Terumbu Hantu, Jul 20
Photo shared by Richard Kuah on facebook.

St. John's Island, Apr 22
Photo shared by James Koh on facebook.

Pulau Semakau North, Jul 20
Photo shared by Loh Kok Sheng on facebook..

Pulau Semakau East, Jul 18
Photo shared by Frances Loke on facebook..

Beting Bemban Besar, Aug 12
Photo shared by Loh Kok Sheng on flickr.

Terumbu Bemban, Jun 10
Photo shared by Loh Kok Sheng on his blog.

Terumbu Pempang Tengah, Jul 12
Photo shared by Loh Kok Sheng on flickr.

Pulau Salu, Apr 21
Photo shared by Loh Kok Sheng on facebook..


  • 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.
  • Borneman, Eric H. 2001. Aquarium Corals: Selection, Husbandry and Natural History T.F. H Publications. 464 pp
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