|
|
|
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.
|
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)
|
+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.
|
|
|