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Phylum Mollusca > Class Gastropoda > Family Architectonicidae
Clear sundial snail
Architectonica perspectiva

Family Architectonicidae
updated Sep 2020

Where seen? This cicular snail with a mesmerising spiral is sometimes encountered on our Southern shores on sandy areas near reefs. Elsewhere, it is considered moderately common and usually found subtidally on sandy and muddy bottoms, from depths of 10 to 120m, mostly between 10 and 65m.

Features: 5-7cm in diameter. Shell thick and coils to form a disc with a flat base. Shell pattern of spirals in white, black and shades of brown. Body and fat tentacles are striped too, to match the shell. The operculum thin, flat and made of a horn-like material.

Sisters Island, Jan 10

Pulau Hantu, Mar 10
What does it eat? It is said to eat burrowing sea anemones and sea pens. The mouth region is lined with a tough cuticle as a protection against stings of their prey.

Laying egg string.
St. John's Island, May 09

Photo shared by Loh Kok Sheng on his blog.

Photo shared by Loh Kok Sheng on his blog.
Baby sundials: It lays long egg strings.

Status and threats: The Clear sundial snail is listed as 'Endangered' in the Red List of threatened animals of Singapore. The original shores where they were found have been lost to reclamation.

Clear sundial snails on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores

Changi, May 17
Photo shared by Marcus Ng on facebook.

Changi, May 17
Photo shared by Loh Kok Sheng on facebook.

Kusu Island, Aug 17

Photo shared by Richard Kuah on facebook.

Cyrene Reef, Nov 17

Photo shared by Loh Kok Sheng on facebook.

Filmed at Pulau Hantu on 12 Apr 09

sundial snail @ Pulau Hantu 12Apr2009 from SgBeachBum on Vimeo.



  • Tan Siong Kiat & Chan Sow-Yan. 31 Aug 2017. Recent sightings of two species of sundial shells at eastern Singapore. Singapore Biodiversity Records 2017: 116-118.
  • 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.
  • 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.
  • Abbott, R. Tucker, 1991. Seashells of South East Asia. Graham Brash, Singapore. 145 pp.
  • Gosliner, Terrence M., David W. Behrens and Gary C. Williams. 1996. Coral Reef Animals of the Indo-Pacific: Animal life from Africa to Hawaii exclusive of the vertebrates Sea Challengers. 314pp.
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