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Phylum Mollusca > Class Bivalvia > Family Cardiidae
Strawberry cockle
Fragum unedo
Family Cardiidae
updated May 2020

Where seen? This pretty clam is not often seen, usually on sandy shores near reefs. Possibly they are more common but hidden beneath the sand. Elsewhere, they are shallow burrowers in sandy bottoms, often occuring in dense populations.

Features:
4-6cm. The sturdy two-part shell is heavy, squarish with strong ribs marked with little red beads.

Terumbu Pempang Darat, Jun 10
What does it eat? Unlike most other bivalves, the strawberry cockle harbours symbiotic zooxanthellae (a kind of single-celled algae) in its body mantle. The zooxanthellae produce food through photosynthesis which it shares with the clam. To maximise the productivity of its "farm", when submerged, the clam exposes its body mantle to sunlight by sticking it out of the shell and above the surface. In this habit, it is similar to Giant clams. It also filter feeds - when submerged, it opens the valves and sucks in water to filter out edible bits.

Human uses: Elsewhere, it is used in decorative shellcraft and may be eaten by coastal dwellers.

Buried with only 'teeth' showing.
Pulau Semakau, Jan 20

When shell is exposed after sand is removed.
Pulau Semakau, Jan 20

Body mantle sticking out of the shell.
Pulau Semakau North, 16
Photo shared by Russel Low on facebook.

Strawberry cockles on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores


Lazarus Island, Nov 14
Photo shared by Loh Kok Sheng on flickr.

Kusu Island, Jun 21
Photo shared by Jianlin Liu on facebook.
 


Cyrene Reef, Nov 17
Photo shared by Loh Kok Sheng on facebook.

Cyrene Reef, Nov 17
Photo shared by Loh Kok Sheng on facebook.

Cyrene Reef, Feb 17
Photo shared by Loh Kok Sheng on facebook.


Body mantle sticking out of the shell.
Cyrene Reef, Feb 16
Photo shared by Heng Pei Yan on facebook.

Cyrene Reef, Feb 16
Photo shared by Heng Pei Yan on facebook.


Cyrene Reef, Jun 20
Photo shared by Kelvin Yong on facebook.

Beting Bemban Besar, May 17
Photo shared by Russel Low on facebook.


Pulau Semakau South, Jul 15

Photo shared by Heng Pei Yan on her blog.

Pulau Semakau West, Jan 21
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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