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.

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 ...

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.