Panopea generosa

The geoduck (pronounced gooey-duck), Panopea generosa, is a species of very large, edible, saltwater clam in the family Hiatellidae, native to the west coast of North America and especially abundant in the Pacific Northwest - Washington state and British Columbia.  The geoduck is the largest species of burrowing clam in the world: the shell of the clam ranges from 15 cm (5.9 in) to over 20 cm (7.9 in) in length.  In addition, its extremely long siphons, through which the underground clam draws in and expels marine water from above the substrate in order to filter feed on phytoplankton, can be more than 1 m (3.3 ft) in length, far to big to retract into the shell like other clams.  They usually live subtidally, from the 0 tide line to depths of 110 m (360 ft) of water, and buried as deep as their siphons allow in mud, sand or silt; in Puget Sound the tips of their siphons are only exposed at very low tides.  Geoducks are also one of the longest-lived animals of any type, living up to 168 years (Bureau et al. 2002; Orensanz et al. 2003).  As adults they have very few predators other than humans.  The common name is thought to be derived from the Nisqually Native American word gwídeq meaning "dig deep," and has multiple spellings; likewise they have acquired multiple scientific synonyms through their complicated taxonomic history, including the often used P. abrupta (Vadopalas 2010; Washington Department of Fish and Wildlife 2013).

In the 1970s a commercial fishery for geoduck clams opened up and in recent decades a huge demand from Asian markets has developed.  These clams are now farmed as well as harvested in the wild.  The clams currently sell for huge sums of money, in China they fetch more than US$150/pound (US$330/kg; Welch 2012) and now require policing by the Washington Dept. of Fisheries and Wildlife for illegal harvesting (Vedder 2011; Welch 2012).  Farming techniques are under scrutiny for their possible negative environmental impact (e.g. Ruesink and Rowell 2012; Brown and Thuesen 2011; Orensanz et al. 2004; Washington Sea Grant 2013).

Genomic DNA is available from 3 specimens with morphological vouchers housed at British Antarctic Survey