Bryan McAllister’s personal reference notebook
July 30, 2026Short & citedBlog
Civic Viewpoint.
A quiet encyclopedia with a personal desk
Field Notes • Biology

Geoduck

The geoduck is a large burrowing saltwater clam, scientifically known as *Panopea generosa*.

Updated July 30, 20261 min readCited sources

The geoduck is a large burrowing clam native to the Pacific coast of North America. It is known for its long siphon and high value as a seafood delicacy.

What it is

The geoduck (*Panopea generosa*) is a marine bivalve mollusc and the largest known burrowing clam. Its most distinctive feature is a very long siphon that can extend up to 1.3 m and cannot be fully retracted into the shell. The shell itself is rectangular to square-shaped, white to light brown, and typically reaches 180–230 mm in length.

Where it lives

Geoducks are native to the Pacific coast of North America, from Alaska to Baja California. They live buried in sand, mud, or gravel in intertidal and shallow subtidal zones, at depths from the intertidal down to at least 110 m. In Canada, they are especially common along the coast of British Columbia.

Why it matters

Geoducks are commercially harvested and farmed, particularly in Washington State and British Columbia. They are considered a high-value seafood item, often exported and sold at premium prices. In Canada, the geoduck supports a significant commercial fishery and is part of the regional seafood culture.

In short

  • Largest known burrowing clam in the world.
  • Lives buried in coastal sediments from Alaska to Baja California.
  • Siphon can extend up to 1.3 m.
  • High-value seafood, commercially harvested in BC and Washington.
Canadian angle

Geoduck is native to the Pacific coast of Canada, especially British Columbia, where it supports commercial fisheries and is part of regional seafood culture.

Quick questions

What is a geoduck clam?
A geoduck is a large burrowing marine clam, *Panopea generosa*, native to the Pacific coast of North America and known for its long siphon and large size.
How big do geoduck clams get?
Their shells are typically about 180–230 mm long, and individuals may weigh up to about 3.6 kg. The siphon can extend to about 1.3 m.
Is geoduck expensive?
Yes. Geoduck is generally considered a high-value seafood product, and prices can be high in retail and restaurant markets, especially for live or imported product.

Sources

  1. Fisheries and Oceans Canadahttps://www.dfo-mpo.gc.ca/species-especes/profiles-profils/geoduck-clam-panope-pac-eng.html
    Supports: Species identity, size description, habitat depth, and Canadian/Pacific distribution.
  2. Alaska Department of Fish and Gamehttps://www.adfg.alaska.gov/index.cfm?adfg=geoduck.printerfriendly
    Supports: Species identity, maximum shell size, weight, and distribution from California to Alaska.
  3. Encyclopaedia Britannicahttps://www.britannica.com/animal/geoduck
    Supports: Scientific classification, habitat, shell length, siphon length, and maximum weight.
  4. National Oceanic and Atmospheric Administrationhttps://www.noaa.gov/species/geoduck
    Supports: Distribution along the U.S. West Coast and commercial harvest/aquaculture context.
  5. Washington Department of Fish and Wildlifehttps://wdfw.wa.gov/species-habitats/species/panopea-generosa
    Supports: Abundance in Puget Sound, range, and commercial fishery context.
  6. BBC Newshttps://www.bbc.com/news/magazine-33261666
    Supports: High market value and examples of restaurant pricing.
  7. IFLSciencehttps://www.iflscience.com/what-is-a-geoduck-the-oceans-giant-burrowing-clam-57981
    Supports: Common preparation methods such as raw slicing and brief blanching.