These bivalve mollusks come in hard-shell and soft-shell varieties.
Hard-shell: East Coast varieties include Littleneck clams (less than 2" diameter), cherrystone clams (2 1/2" diameter) and chowder clams (3" diameter or larger) also called "large clams" or quahogs--an American Indian name. West Coast varieties include Pacific littleneck clams, pismo and butter clams.
Soft-shell clams or soft clams have thin brittle shells and a neck that extends beyond the shell for siphoning water and food: steamer clam, razor clam and geoduck clam. The geoduck (GOO-ee-duck) is 6 inches long with a neck that can stretch up to 1 1/2 feet.
Season: available year-round
How to select: Sold live in the shell. Closed hard-shell clams are alive, if open tap the shell and if it snaps shut they are still alive. For soft-shell clams touch the neck; if it moves, it's alive. If shucked, look for plumpnes and clear liquid.
How to store: Up to 2 days alive in the refrigerator; up to 4 days shucked.
How to prepare: bake, broil, fry, raw, roast, steam
Matches well with: bacon, bread crumbs, butter, chiles, chives, cream, curry, garlic, ginger, horseradish, lemon, olive oil, onion, paprika, parsley, potatoes, sake, shallots, sour cream, Tabasco sauce, tarragon, tartar sauce, thyme, tomatoes, vinegar, white wine