soft corals text index | photo index
Phylum Cnidaria > Class Anthozoa > Subclass Alcyonaria/Octocorallia > Order Alcyonacea
Knobbly soft coral
Carijoa sp.*
Family Clavulariidae

updated Nov 2019

Where seen? This colony of bumpy animals is commonly seen on some of our Northern shores, but often overlooked as it resembles a plant. It grows on large boulders, jetty pillings and other hard surfaces.

Features: 5-8cm long. The colony comprises a cluster of sparsely branched 'stems', forming short bushes or bushy fringes on hard surfaces. Each long stem is a primary polyp bearing large secondary polyps in capsules (about 1cm long) regularly arranged along the length. The polyps can retract completely into the capsule. Colour usually white although the colony may be overgrown with colourful encrusting sponges and ascidians. The animals do not have symbiotic algae (zooxanthellae) and thus can be found in murky water and dark places.

Sometimes mistaken for a sea fan (Order Gorgonacea) or a hydroid (Order Hydrozoa).

Keppel Bay, Oct 09

Secondary polyps emerge from a capsule.

Eight branched tentacles.

Pulau Sekudu, Apr 06

Changi, Jul 07

Changi, Jul 12

Growing on a living sea fan.

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

Knobbly soft corals on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores

Pulau Ubin, Jul 17
Photo shared by Loh Kok Sheng on facebook.

Terumbu Pempang Laut, Aug 16
Photo shared by Loh Kok Sheng on facebook.

Grateful thanks to Chandran Rethnaraj for identifying this animal.



  • Fabricius, Katharina and Philip Alderslade, 2001. Soft Corals and Sea Fans. Australian Institute of Marine Science and the Museum and Art Gallery of the Northern Territoriy. 264 pp.
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