The shells of clams range from gray to speckled brownish-white. In contrast, mussels are dark blue to dark green or black, ...

Lupins have a harder shell and are less vulnerable to the highly aggressive blue crab, which has wreaked havoc this year in Italy's main clam growing grounds in Veneto and Emilia-Romagna.

Hermit crabs are omnivorous scavengers, eating microscopic mussels and clams ... like blue crabs, in that they don’t have a uniformly hard exoskeleton and can’t grow their own shells.

Like oysters and mussels, clams are bivalves, a kind of mollusk that's encased in a shell made of two valves, or hinging parts. And that shell comes in all different sizes. There are small clams ...