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Phylum Mollusca > Class Bivalvia > Family Pectinidae
Coral scallop
Pedum spondyloideum*

Family Pectinidae
updated Oct 2016

Where seen? These little clams are often seen among hard corals on many of our Southern shores. The clam is embedded in living coral, excavating the hard coral to create a cavity for itself and attaching to the coral by byssus threads. The clam is usually completely surrounded by living tissue.

Features: Diameter 1-1.5cm. A circular two-part shell. In some the shell is covered with encrusting fluff, in others, some patterns may be seen. They are often seen in hard corals with branching or leafy forms such as Acropora corals (Acropora sp.), Crinkled sandpaper coral (Psammocora sp.) and Branching pore coral (Porites sp.).

Coral-clam cooperation: The coral provides the clam a safe place with support and protection. The clam may improve water circulation for the coral which helps the coral feed. A study showed that the clam helped reduce the impact of predatory Crown-of-Thorns sea stars (Acanthaster planci) repeatedly spitting out jets of water. On the other hand, the clam may weaken the coral as it excavates a cavity within the coral structure.

This page includes all the little clams found in hard corals, for convenience of display. It is possible that they are different species and may even not be scallops but belong to other families.

Pulau Hantu, Apr 07

Beting Bemban Besar, Apr 10

Sisters Island, Feb 10

Tanah Merah, Jun 11

*Species are difficult to positively identify without close examination.
On this website, they are grouped by external features for convenience of display.

Coral scallops on Singapore shores

Photos of Coral scallops for free download from wildsingapore flickr

Distribution in Singapore on this wildsingapore flickr map

Labrador, Aug 17
Photo shared by Loh Kok Sheng on facebook.

Terumbu Hantu, Jun 16
Photo shared by Marcus Ng on flickr.

Terumbu Bemban, Jul 11
Photo shared by Loh Kok Sheng on his blog.

Terumbu Pempang Tengah, Apr 13
Photo shared by Loh Kok Sheng on flickr.

Pulau Salu, Jun 10

Pulau Salu, Jun 10

Terumbu Berkas, Jan 10



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