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Phylum Mollusca > Class Gastropoda
Olive snails
Family Olividae
updated Sep 2020

Where seen? These bullet-shaped snails are sometimes seen on the silty sandy shores near seagrasses. These burrowing snails are more often seen above the ground at night or with the incoming tide. They leave a typical trail on the sand surface as they burrow beneath. Elsewhere, they are common in well-aerated, clean sand.

Features: 2-5cm. Shell cylindrical and looks like an olive. The shell opening is narrow and many members of this family do not have an operculum. Like a cowrie, the living olive snail envelopes its shell in its mantle. This is why the shell is so glossy. Most are burrowers that live in the sand. Relying mostly on the sense of smell to find their prey, their eyes are greatly reduced or absent. Olive snails are notoriously variable in colour, even within the same species.

Sometimes confused with Cone snails (Family Conidae) which can be DEADLY and should NOT be handled. If you are not sure what the snail is, do not handle it.

Changi, Jun 06

Button snails leaping away from a burrowing Olive snail.
East Coast Park, Aug 11
What do they eat? Olive snails are predators. They feed on other snails, small crustaceans and also scavenge on dead animals. An Olive snail remains in the sand while it sticks its siphon above the surface. When it 'smells' suitable prey, it emerges to engulf the prey with its large foot, smothering it with slime and then dragging it beneath the sand to be eaten at leisure.

Human uses:
Although sometimes collected for food, they are mainly collected for their attractive shells for the shell trade.

Status and threats: The Orange-mouth olive snail is listed as 'Vulnerable' on the Red List of threatened animals of Singapore.

Some Olive snails on Singapore shores



White lip ends at about
half the shell opening length.
Shell opening orange or orangey.

Spire flattened
with short pointed tip.


White lip ends at about
half the shell opening length.
Shell opening purplish brown.

Spire conical.


White lip ends at about
half the shell opening length.
Shell opening violet.

Short conical spire.


White lip ends at less
than half the shell opening length.
Shell opening violet.

Short conical spire.


shared by Neo Mei Lin on her blog

Family Olividae recorded for Singapore
from Tan Siong Kiat and Henrietta P. M. Woo, 2010 Preliminary Checklist of The Molluscs of Singapore.
in red are those listed among the threatened animals of Singapore from 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.
^from WORMS.
+Other additions (Singapore Biodiversity Records, etc)

  Family Olividae
  +Oliva hanleyorum
Oliva irisans
Oliva lignaria
Oliva miniacea
(Orange-mouth olive snail)
(VU: Vulnerable)=Oliva sericea
Oliva mustelina
(Weasel olive snail)
Oliva oliva
(Common olive snail)
Oliva reticulata
Oliva sidelia
Oliva tigridella
(Tigerish olive snail)

Olivella plana
(^now in Family Olivellidae)

Links
  • New Singapore record of the olive shell, Oliva hanleyorum, 20 December 2019, Calvin Leow Jiah Jay, Singapore Biodiversity Records, 2019: 163 ISSN 2345-7597, National University of Singapore.
  • Orange-mouth olive snail (Olivia sericea) on the NParks Flora and Fauna website.
  • Family Olividae on The Gladys Archerd Shell Collection at Washington State University Tri-Cities Natural History Museum website: brief fact sheet on moon snails with photos.
  • Family Olividae in the Gastropods section by J.M. Poutiers in the FAO Species Identification Guide for Fishery Purposes: The Living Marine Resources of the Western Central Pacific Volume 1: Seaweeds, corals, bivalves and gastropods on the Food and Agriculture Organization of the United Nations (FAO) website.

References

  • 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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