What's the noun for clammers? Here's the word you're looking for.
clam
A bivalvemollusk of many kinds, especially those that are edible; for example the soft-shell clam (Mya arenaria), the hard clam (Mercenaria mercenaria), the sea clam or hen clam (Spisula solidissima), and other species. The name is said to have been given originally to the Tridacna gigas, a huge East Indian bivalve.