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Phylum Mollusca > Class Gastropoda > Family Trochidae
Toothed top shell snail
Monodonta labio
Family Trochidae
updated Sep 2020

Where seen? This snail with a tooth in its shell opening is commonly seen on many of our shores. Often seen in groups on boulders, stones and seawalls on many of our shores. It is more active at night.

Features: 3-4cm. Shell thick heavy, an asymmetrical cone with spirals of rounded bumps. Colour usually grey or greenish grey. Mono donta means 'one-toothed'. Indeed, there is a single large tooth-shaped structure at the shell opening which is white and smooth. Operculum, thin, made of a horn-like material with concentric rings, yellow. The flexible operculum allows the animal to withdraw deep into the coils of the shell. Hopefully, safe from prying claws of hungry crabs. Body pale, large foot, edge of the mantle fringed with long tentacles. A pair of long tentacles at the head.

Sometimes confused with the Turban snail (Family Turbinidae) which has a shell with more distinct whorls and a thick, chalky operculum. While many Top snails have a more conical shell and a thin operculum made of a horn-like material. Here's more on how to tell apart turban and top shell snails.

Kusu Island, May 05

St. John's Island, Aug 05

Toothed top shell snails on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores

East Coast Park (B), Jun 21
Photo shared by Vincent Choo on facebook.

Sentosa Serapong, May 16
Photo shared by Ivan Kwan on facebook.

Pulau Sudong, Dec 09
Photo shared by Ivan Kwan on his flickr.



  • Tan Siong Kiat and Henrietta P. M. Woo, 2010 Preliminary Checklist of The Molluscs of Singapore (pdf), Raffles Museum of Biodiversity Research, National University of Singapore.
  • Cedric Kai Wei Tan. 19 November 2009. Effects of Trenching on shell size and density of Turbo Brunneus (Gastropoda: Turbinidae) and Monodontia labio (Gastropoda: Trochidae). Nature in Singapore 2009 2: 421–429.
  • Tan, K. S. & L. M. Chou, 2000. A Guide to the Common Seashells of Singapore. Singapore Science Centre. 160 pp.
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