Manila Clams are a type of bivalve, edible mollusks which live in sand and are generally found at low tide. The Manila clam is distinct from other clam species due to its elongated and flattened shell. Manila clams tend not to bury themselves as deeply in the sand as Littlenecks and other clams. In the U.S. they are most commonly found in the Pacific Northwest. They are not indigenous to this area, but were accidentally introduced in the 1930's with oysters that were brought over from Japan. Like other clams, they should be cleaned well before use, by scrubbing well under running water to remove all dirt and sand. Any clams with partially opened shells, or heavier shells are probably dead and should be discarded. A clam knife is used to open the shell and release the meat from its attachment to the top shell.