Asian clam

Corbicula fluminea


Photo credit: Colette O'Flynn


Habitat: Freshwater lakes and streams of all sizes with mud, silt, sand and gravel benthic substrate.


Description: Typically this bivalve grows up to 25 mm in length but larger forms are know which can grow up to 50 to 65 mm. C. fluminea has a yellowish brown to black shell with concentric, evenly spaced ridges on the shell surface.


Origin and Distribution: Originated in China, Korea, southeastern Russia, and the Ussuri Basin. Now widespread in Europe and the United States.



  • Asian clam reaches high densities and colonises suitable substrates. 
  • It has similar impacts to the zebra mussel, competing with other species for food and space. 
  • Water based industries, such as hydroelectric power stations and water abstraction for household use may be faced with higher costs due to the clogging of intake pipes by this species. In the US one estimate from 1980 put the costs of correcting this problem at an estimated 1 billion dollars annually (ISSG). 
  • They can also negatively impact on sand/gravel abstraction.


Where is it found in Ireland? Corbicula fluminea was first recorded in Ireland in 2010 within the Barrow Navigation.


See the National Invasive Species Database for more information on the distribution of this species in Ireland.


How did it get here? Corbicula could have been introduced to Ireland in boat bilge water as live bait or as a result of escapes from the aquarium trade. C. fluminea are known as "pygmy" or "gold" clams in the aquarium trade.


Prevent Spread

  • Do not use Corbicula as bait.
  • Do not transfer water from one waterbody to another.
  • Do not bring Corbicula with you when you travel to Ireland.
  • Report all sightings.



Invasive Species Ireland

Invasive Species Ireland