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Phylum Mollusca > Class Gastropoda > Family Naticidae
Oval moon snail
Polinices mammilla
Family Naticidae
updated Aug 2020

Where seen? This oval white moon snail is among our most commonly encountered. Usually seen in numbers on many our Southern sandy shores. Elsewhere, it is abundant on sandy bottoms associated with coral reefs.

Features: 5-6cm. Shell smooth glossy, thick heavy, oval, the spiral tip smoothly sticking out so the overall shape resembles a teardrop or breast (Mamma means 'breast' in Latin). Shell pattern plain white, sometimes with large irregular patches of brown, black, orange or yellow. On the underside, a large bump and shallow depression next to the bump. Operculum smooth, made of a thin horn-like material, amber yellow sometimes with dark blotches. Body plain white. It's hard to get a good look at the entire body as the snail retracts quickly and completely into the shell when it is disturbed.

Sometimes mistaken for the Ball moon snail that is easily distinguished by its spherical shell which has a brown-coloured blotch on the underside.

Kusu Island, May 06

Kusu Island, May 06

Cyrene, Aug 17
Photo shared by Marcus Ng on flickr.

Typical trail created when it burrows just beneath the surface.
Terumbu Pempang Laut, Jul 20

Tanah Merah, Aug 09
Human uses: Elsewhere, it is collected in large quantities for food and the shell trade. In Thailand, it is actively collected at low tide by hand and sold by weight for shell craft, in batches of 5,000-10,000 shells.

Sentosa, Jun 09

Sentosa, Jun 09

Oval moon snails on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores


East Coast Park, Mar 10
Photo shared by Loh Kok Sheng on flickr.

Berlayar Creek, Mar 20
Photo shared by Loh Kok Sheng on facebook.

Lazarus Island, Nov 20
Photo shared by Loh Kok Sheng on facebook.


Pulau Semakau East, Jul 15
Photo shared by Loh Kok Sheng on facebook.

Pulau Sudong, Dec 09
Photo shared by Loh Kok Sheng on flickr.

Pulau Biola, Jan 22
Photo shared by Toh Chay Hoon on facebook.


Terumbu Raya, Sep 19
Photo shared by Kelvin Yong on facebook.

Terumbu Semakau, Dec 15
Photo shared by Juria Toramae on facebook.


Pulau Semakau South, Oct 20
Photo shared by Loh Kok Sheng on facebook.

Pulau Semakau South, Oct 20
Photo shared by Vincent Choo on facebook.

Links References
  • Tan Siong Kiat and Henrietta P. M. Woo, 2010 Preliminary Checklist of The Molluscs of Singapore (pdf), Lee Kong Chian Natural History Museum, National University of Singapore.
  • Tan, K. S. & L. M. Chou, 2000. A Guide to the Common Seashells of Singapore. Singapore Science Centre. 160 pp.
  • Abbott, R. Tucker, 1991. Seashells of South East Asia. Graham Brash, Singapore. 145 pp.
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