A live specimen of Panopea generosa
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Adapedonta
Family: Hiatellidae
Genus: Panopea
P. generosa
Binomial name
Panopea generosa
Gould, 1850

The Pacific geoduck (/ˈɡiˌdʌk/ GOO-ee-duk; Panopea generosa) is a species of very large saltwater clam in the family Hiatellidae.[1][2] The common name is derived from the Lushootseed name, gʷidəq.

The geoduck is native to the coastal waters of the eastern North Pacific Ocean from Alaska to Baja California.[2] The shell of the clam ranges from 15 centimetres (6 in) to over 20 centimetres (8 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 ft 3 in) in length. The geoduck is the largest burrowing clam in the world.[3] It is also one of the longest-living animals of any type, with a typical lifespan of 140 years;[4] the oldest has been recorded at 179 years old.[5] The precise longevity of geoducks can be determined from annual rings deposited in the shell which can be assigned to calendar years of formation through crossdating.[6][7] These annual rings also serve as an archive of past marine variability.[5][8][9]

Geoduck growth increments


Geoduck for sale at Tsukiji fish market in Tokyo

The name Geoduck is derived from the Lushootseed name for the animal, gʷidəq.[10] The etymology of gʷidəq is disputed. The lexical suffix =əq means "many" in Lushootseed.[10] The Oxford English Dictionary claims it is composed of a root word of unknown meaning and =əq instead meaning "genitals" (referring to the shape of the clam),[11][12] while other researchers claim it is a phrase meaning "dig deep".[13]

It is sometimes known as a mud duck, king clam or, when translated literally from Chinese, an elephant-trunk clam (Chinese: 象拔蚌; pinyin: xiàngbábàng; Jyutping: zoeng6 bat6 pong5).[14]

Between 1983 and 2010, the scientific name of this clam was confused with that of an extinct clam, Panopea abrupta (Conrad, 1849), in scientific literature.[2]


Native to the west coast of Canada and the northwest coast of the United States (primarily Washington and British Columbia), these marine bivalve mollusks are the largest burrowing clams in the world, weighing in at an average of 0.7 kilograms (1+12 lb) at maturity, but specimens weighing over 7 kilograms (15 lb) and as much as 2 metres (6 ft 7 in) in length are not unheard of.[citation needed]

A related species, Panopea zelandica, is found in New Zealand and has been harvested commercially since 1989. The largest quantities have come from Golden Bay in the South Island where 100 tonnes (110 short tons) were harvested in one year. There is a growing concern over the increase of parasites in the Puget Sound population of geoduck. Whether these microsporidium-like parasitic species were introduced by commercial farming is being studied by Sea Grant. Research to date does indicate their presence.[15]

The oldest recorded specimen was 179 years old, but individuals usually live up to 140 years.[4] A geoduck sucks water containing plankton down through its long siphon, filters this for food and ejects its refuse out through a separate hole in the siphon. Adult geoducks have few natural predators, which may also contribute to their longevity. In Alaska, sea otters and dogfish have proved capable of dislodging geoducks; starfish also attack and feed on the exposed geoduck siphon.

Geoducks are broadcast spawners. A female geoduck produces about 5 billion eggs in her century-long lifespan. However, due to a low rate of recruitment and a high rate of mortality for geoduck eggs, larvae, and post-settled juveniles, populations are slow to rebound.[16] In the Puget Sound, studies indicate that the recovery time for a harvested tract is 39 years.[17]

Biomass densities in Southeast Alaska are estimated by divers, then inflated by twenty percent to account for geoducks not visible at the time of survey.[18] This estimate is used to predict the two percent allowed for commercial harvesting.[18]


Main article: Geoduck aquaculture

The world's first geoduck fishery was created in 1970, but demand for the half-forgotten clam was low at first due to its texture.[citation needed] As of 2011, these clams sell in China for over US$33 per kilogram or $15 per pound.[19][20]

The geoduck's high market value has created an $80-million industry, with harvesting occurring in the US states of Alaska, Washington, and Oregon and the Canadian province of British Columbia. It is one of the most closely regulated fisheries in both countries. In Washington, Department of Natural Resources staff are on the water continually monitoring harvests to ensure revenues are received, and the same is true in Canada where the Underwater Harvesters' Association manages the Canadian Fishery in conjunction with Canada's Department of Fisheries and Oceans. The Washington State Department of Health tests water and flesh to assure clams are not filtering and holding pollutants, an ongoing problem. With the rise in price has come the inevitable problem with poaching, and with it the possibility some could be harvested from unsafe areas.[21]

As of 2007, advances in the testing system for contaminated clams have allowed geoduck harvesters to deliver live clams more consistently. The new testing system determines the viability of clams from tested beds before the harvesters fish the area. Previous methods tested clams after harvest. This advancement has meant that 90 percent of clams were delivered live to market in 2007. In 2001, only 10 percent were live.[22] Because geoduck have a much higher market value live, an additional $4.4 to $6.6 per kilogram or $2 to $3 per pound, this development has helped to stimulate the burgeoning industry.

The COVID-19 pandemic disrupted the geoduck industry. Given the near-shutdown of restaurants and seafood markets across the country, demand for live geoducks plummeted. Divers in Southeast Alaska who typically see prices of $11 to $22 per kilogram or $5 to $10 per pound for live geoducks reported prices as low as $2.2 per kilogram or $1 per pound, leading many to stop fishing temporarily.[23]

Environmental impact

Geoduck farming grow-out and harvest practices are controversial,[24] and have created conflicts with shoreline property owners,[25][26][27][28] and concerns from nongovernmental organizations.[29] However, the Environmental Defense Fund has found that bivalves (oysters, mussels, and clams) are beneficial to the marine environment.[30] The water must be certifiably clean to plant geoducks commercially.[31] Regulation was mandated in 2007.[32][33] Studies have been funded to determine short- and long-term environmental and genetic impacts.[34] In southern Puget Sound, the effect of geoduck farming on large mobile animals is ambiguous.[35] A 2004 draft biological assessment, commissioned by three of the largest commercial shellfish companies in the Puget Sound region, identified no long-term effects of geoduck farming on threatened or endangered species.[36]

Culinary uses

The large, meaty siphon is prized for its savory flavor and crunchy texture. Geoduck is regarded by some as an aphrodisiac because of its phallic shape.[3] It is very popular in China, where it is considered a delicacy,[3] mostly eaten cooked in a fondue-style Chinese hot pot. In Korean cuisine, geoducks are eaten raw with spicy chili sauce, sautéed, or in soups and stews. In Japan, geoduck is prepared as raw sashimi, dipped in soy sauce and wasabi. On Japanese menus in cheaper sushi restaurants, geoduck is sometimes substituted for Tresus keenae, a species of horse clam, and labeled mirugai or mirukuigai. It is considered to have a texture similar to an ark shell (known in Japanese as akagai). Mirugai is sometimes translated into English as "giant clam", and it is distinguished from himejako sushi, which is made from Tridacna gigas.

In popular culture

Evergreen State College in Olympia, Washington, has a geoduck as its mascot named Speedy.[37][38]

Geoducks have also earned some internet infamy due to the phallic appearance of their siphons.[39]


  1. ^ Panopea generosa Gould, 1850. Retrieved through: World Register of Marine Species on 28 December 2010.
  2. ^ a b c Vadopalas, B.; T. W. Pietsch; C. S. Friedman (2010). "The proper name for the geoduck: resurrection of Panopea generosa Gould, 1850, from the synonymy of Panopea abrupta (Conrad, 1849) (Bivalvia: Myoida: Hiatellidae)" (PDF). Malacologia. 52 (1): 169–173. doi:10.4002/040.052.0111. S2CID 84189390. Retrieved 2 March 2012.
  3. ^ a b c Morgan, James (19 July 2015). "The 'phallic' clam America sells to China". BBC. Retrieved 20 July 2015.
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  5. ^ a b Edge, David; Reynolds, David; Wanamaker, Alan; Griffin, Daniel; Bureau, Dominique; Outridge, Christine; Wang, Richard; Stevick, Bethany; Black, Bryan (2021). "Multicentennial Proxy Record of Northeast Pacific Sea Surface Temperatures From the Annual Growth Increments of Panopea generosa". Paleoceanography and Paleoclimatology. 36 (9). Bibcode:2021PaPa...36.4291E. doi:10.1029/2021PA004291. S2CID 239151578. Retrieved 13 September 2022.
  6. ^ Kastelle, Craig R.; Helser, Thomas E.; Black, Bryan A.; Stuckey, Matthew J.; C. Gillespie, Darlene; McArthur, Judy; Little, Diana; D. Charles, Karen; Khan, Reziah S. (15 October 2011). "Bomb-produced radiocarbon validation of growth-increment crossdating allows marine paleoclimate reconstruction". Palaeogeography, Palaeoclimatology, Palaeoecology. 311 (1): 126–135. Bibcode:2011PPP...311..126K. doi:10.1016/j.palaeo.2011.08.015.
  7. ^ Black, Bryan A.; Gillespie, Darlene C.; MacLellan, Shayne E.; Hand, Claudia M. (December 2008). "Establishing highly accurate production-age data using the tree-ring technique of crossdating: a case study for Pacific geoduck (Panopea abrupta)". Canadian Journal of Fisheries and Aquatic Sciences. 65 (12): 2572–2578. doi:10.1139/F08-158.
  8. ^ Black, Bryan A.; Copenheaver, Carolyn A.; Frank, David C.; Stuckey, Matthew J.; Kormanyos, Rose E. (15 July 2009). "Multi-proxy reconstructions of northeastern Pacific sea surface temperature data from trees and Pacific geoduck". Palaeogeography, Palaeoclimatology, Palaeoecology. 278 (1): 40–47. Bibcode:2009PPP...278...40B. doi:10.1016/j.palaeo.2009.04.010.
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  12. ^ "geoduck". Unabridged (Online). n.d. Retrieved 29 March 2007.
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  14. ^ Chappell, Hilary M. (2015). Diversity in Sinitic Languages. Oxford University Press. p. 171. ISBN 978-0-19-103573-9.
  15. ^ "Geoduck Aquaculture Research Program" (PDF). Geoduck Aquaculture Research Program, Washington Sea Grant. Retrieved 18 April 2014.
  16. ^ Willner, Georgina B. (June 2006). The Potential Impacts of the Commercial Geoduck (Panope generosa) Hydraulic Harvest Method on Organisms in the Sediment and at the Water-Sediment Interface in Puget Sound (PDF) (Master thesis). Olympia, Washington: The Evergreen State College. Retrieved 1 January 2023.
  17. ^ Palazzi, David C.; Goodwin, Lynn; Bradbury, Alex; Sizemore, Bob; Washington (state) (23 May 2001). Espy, Leigh; Sturges, Susan; Ladenburg, Candis; Sabottke, Blanch (eds.). Final Supplemental Environmental Impact Statement: State of Washington Commercial Geoduck Fishery (PDF) (Report). Olympia WA: State of Washington Department of Natural Resources: Department of Fish and Wildlife. p. 5. Retrieved 1 January 2023.
  18. ^ a b Rumble, JM; Hebert, KP; Siddon, CE (2012). "Estimating Geoduck Harvest Rate and Show Factors in Southeast Alaska". In: Steller D, Lobel L, Eds. Diving for Science 2012. Proceedings of the American Academy of Underwater Sciences 31st Symposium. Archived from the original on 29 September 2013. Retrieved 29 September 2013.((cite journal)): CS1 maint: unfit URL (link)
  19. ^ Vedder, Tracy (3 March 2011). "Chinese mafia rakes in millions from 'Puget Sound gold'". Archived from the original on 6 June 2011. Retrieved 6 March 2011.
  20. ^ Welch, Craig, 2012. NW geoducks fetch top dollar in China, and as prices soar, so do concerns about illegal harvesting in Puget Sound, The Seattle Times, 22 April 2012, pp 1 & 10.
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  22. ^ Ess, Charlie. "Toxin test gives live market a boost; quota also gets a significant bump". National Fisherman. Archived from the original on 14 November 2006. Retrieved 1 August 2008.
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  36. ^ "Programmatic Biological Evaluation" (PDF). Retrieved 23 May 2017.
  37. ^ "Speedy, Evergreen's Geoduck Mascot". Retrieved 20 September 2019.
  38. ^ "10 Weird And Hilarious College Mascots". 11 November 2011. Retrieved 20 September 2019. 2. Evergreen State - The Geoduck
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