The geoduck is a species of very large saltwater clam, a marine bivalve mollusk in the family Hiatellidae.
The shell of this clam is large and contails small wings, about 15 centimetres (5.9 in) to over 20 centimetres (7.9 in) in length, but the extremely long siphons make the clam itself very much longer than this: the "neck" or siphons alone can be 1 metre (3.3 ft) in length.
The world's first geoduck fishery was created in 1970, but demand for the half-forgotten clam was low due to its texture. Today, they sell in Asiafor up to US$30/lb (US$65/kg). Its large, meaty siphon is prized for its savory flavor and crunchy texture. Geoduck is also regarded by some as an aphrodisiac. It is extremely popular in China, where it is considered a delicacy. Geoduck is mostly eaten cooked in a fondue-style Chinese hot pot or raw sashimi style, dipped in soy sauce and wasabi. In Korean cuisine, geoducks are eaten raw with spicy chili sauce, sautéed, or in soups and stews. On Japanese menus, geoduck is called mirugai or mirukuigai. It also has a texture similar to an Ark Shell (Akagai). (Although mirugai is sometimes translated to English as "Giant Clam", it is distinguished from "Himejako" sushi made from Tridacna gigas.)