Description

Also known as Arc, Burrowing Mollusc, Heart Cockle, Mussel, True Cockle.

Found partially buried, over mud and sandy bottoms, of coastal reefs.
They feed on plankton.
Length - 7cm
Depth - 0-70m
Widespread Western Central Pacific

Most Bivalves are permanently anchored in fissures or depressions in the rock surface of the reef, some may become covered in algae and other marine life.
Other Bivalves swim free, either by a well developed foot or propelled along by a jet of water from their mantle cavity. Ref: http://www.marinespecies.org/aphia.php?p=taxdetails&id=381322