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Phylum Mollusca > Class Polyplacophora
Jewelled chiton
Acanthopleura gemmata
Class Polyplacophora
updated Jun 2020

Where seen? It has been seen on natural rocky shores on our Southern shores. Many were also seen on artificial seawalls, often hidden in crevices in the concrete slabs.

Features: Up to 12cm long, the oval flattened body is covered with 8 overlapping plates along the centre. A thick, stiff mantle forms a girdle around the plates to the body edges. The girdle is covered with bristles.

Sometimes mistaken for a scale worm which is a polychaete worm that also has overlapping scales but has well developed tentacles and rows of bristles along the sides of the body.

St. John's Island, Sep 09

A large and small one found on artificial seawalls.
Seringat-Kias, Jan 19
What do they eat? Like snails, chitons have a rough 'tongue' called a radula that is used to rasp off fine algae or other encrustations. They creep slowly about when submerged and at night. When exposed at low tide and during the day, they are usually motionless in some dark, wet hiding place.

Status and threats: It is listed as 'Endangered' on the Red List of threatened animals of Singapore.

Jewelled chitons on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores


East Coast (PCN), May 21
Photo shared by Vincent Choo on facebook.


Labrador, Nov 20
Photo shared by Vincent Choo on facebook.

Sentosa Tg Rimau, Nov 20
Photo shared by Richard Kuah on facebook.


Lazarus Island, Nov 17
Photo shared by Rene Ong on facebook.

Seringat-Kias, Aug 12
Photo shared by Loh Kok Sheng on flickr.


Pulau Tekukor, Sep 18
Photo shared by Liz Lim on facebook.

Pulau Tekukor, Mar 22
Photo shared by Vincent Choo on facebook.

Links References
  • Tan, S. K. & H. P. M. Woo, 2010. A preliminary checklist of the molluscs of Singapore. Lee Kong Chian Natural History Museum, National University of Singapore, Singapore. 78 pp.
  • Davison, G.W. H. and P. K. L. Ng and Ho Hua Chew, 2008. The Singapore Red Data Book: Threatened plants and animals of Singapore. Nature Society (Singapore). 285 pp.
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