The Pacific geoduck (/ˈɡuːiːdʌk/ "gooey duck"), scientific name Panopea generosa, is a species of very large, edible saltwater clam in the family Hiatellidae.The common name is derived from a Lushootseed (Nisqually) word gʷídəq.
The geoduck is native to the west coast of North America. The shell of the clam ranges from 15 centimetres (5.9 in) to over 20 centimetres (7.9 in) in length, but the extremely long siphons make the clam itself much longer than this: the "neck" or siphons alone can be 1 metre (3.3 ft) in length. The geoduck is the largest burrowing clam in the world. It is also one of the longest-living animals of any type, with a lifespan of up to 140 years; the oldest has been recorded at 168 years old.