The Geoduck (Trunk Clam)

The geoduck 

The geoduck (pronounced /ˈɡuː.iːdʌk/ "gooey duck"^[1]), Panopea abrupta, is a species of very large saltwater clam, a marine bivalve mollusk in the family Hiatellidae.

The shell of this clam is large, about 15 to over 20 cm in length (about 7 to 9 inches), but the extremely long siphons make the clam itself very much longer than this: the "neck" or siphons alone can be one meter in length.

The unusual name of the clam is derived from a Lushootseed (Nisqually) word gʷídəq^[2] meaning "dig deep", and its phonemically counterintuitive spelling is likely the result of poor transcription rather than anything having to do with ducks. Alternate spellings include gweduc, gweduck and goiduck. It is sometimes known as the king clam, or when translated literally from the Chinese characters 象拔蚌, the elephant trunk clam.

 

Biology

Native to the northwest coast of the United States and Canada (primarily Washington and British Columbia), the geoduck is the largest burrowing clam in the world, weighing in at an average of one to three pounds (0.5–1.5 kg) at maturity, but specimens weighing over 15 pounds (7.5 kg) and as much as 2 meters (6 ft) 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 were harvested in one year.

Geoducks are one of the longest-living organisms in the Animal Kingdom. They have a life expectancy of about 146 years, with the oldest recorded at over 160 years. Scientists speculate that the geoduck's longevity is the result of low wear and tear. A geoduck sucks plankton down through its long siphon, filters them 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—in comparison, a human female produces about 500 viable ova during the course of her life.