Freshwater Invasive Clams

Common Name

Freshwater Invasive Clams (Bucket Clam, Asian Clam)

Species Name

Corbicula fluminea

Distribution / Status (Tahoe)

Established invasive; first detected 2002; widespread in Tahoe’s littoral zone

Diagnostic Features

Larger triangular shell with strong concentric ridges and anterior umbo

Commonly Confused Species

Juvenile Western Pearlshell Mussel (Margantirera falcata); Pea/Fingernail Clams (Pisidium spp.)

Shell Shape / Form

Triangular to heart-shaped; more robust and heavy

Shell Size

Much larger; 10–25 mm (occasionally > 30 mm)

Shell Thickness

Thick, solid shell

Hinge Features

Strong, coarse hinge teeth forming pronounced ridges

Shell Sculpture / Texture

Concentric ridges well defined across shell surface

Color / Patterning

Yellow-brown to dark brown, often with greenish tinge

Umbonal Position (bivalves)

Prominent, anterior umbo

Periostracum Condition

Thicker, duller periostracum; persists after death

Soft Body Features

Pale yellow foot; short paired siphons visible when extended

Habitat Type

Shallow littoral zones of lakes and rivers; warm, nearshore littoral zones and marinas

Substrate Preference

Sand, Silt or Gravel

Depth Range

0 - 5 m typically (also found as deep as 40m)

Temperature Range

Optimal 16–30 °C; dies below 2 °C for prolonged periods

Association / Behavior

Active burrowers; can migrate short distances using foot

Ecological Role / Impact

Alters nutrient cycling, promotes algal blooms, clogs infrastructure, outcompetes natives

Reproduction

Separate sexes; broadcast spawner; up to 70,000 juveniles per year/female

Growth Lines / Rings

Distinct concentric ridges/rings; prominent external ridges mark rapid growth periods; often used to differentiate Corbicula from small native clams.

References

Golden Sands RC&D Council, Inc. (n.d.). Aquatic Invasive Species Quick Guide: Asian Clam. Golden Sands Resource Conservation and Development Council, Inc. University of Wisconsin.

Nedeau, E. J., Smith, A. K., Stone, J., & Jepsen, S. (2009). Freshwater Mussels of the Pacific Northwest (pp. 31–35).

Pennsylvania Sea Grant. (n.d.). Basket clam: Aquatic invasive species fact sheet. Pennsylvania State University. Retrieved from https://seagrant.psu.edu/resources/resource-item/basket-clam-ais-fact-sheet/

Smithsonian Environmental Research Center. (n.d.). Species summary: Limnoperna fortunei (golden mussel). National Exotic Marine and Estuarine Species Information System (NEMESIS). Retrieved October 28, 2025, from https://invasions.si.edu/nemesis/species_summary/81387

University of Wisconsin Sea Grant Institute. (n.d.). Asiatic clam (Corbicula fluminea). University of Wisconsin–Madison, Sea Grant Institute. Retrieved from https://www.seagrant.wisc.edu/our-work/focus-areas/ais/invasive-species/invasive-species-fact-sheets/mollusks/asiatic-clam/

U.S. Department of Agriculture, National Invasive Species Information Center. (n.d.). Asian clam (Corbicula fluminea). U.S. Department of Agriculture. Retrieved from https://www.invasivespeciesinfo.gov/aquatic/invertebrates/asian-clam

U.S. Fish and Wildlife Service. (2024). Ecological risk screening summary: Basket clam (Corbicula fluminea) – High risk. U.S. Department of the Interior, Fish and Wildlife Service.

Wittmann, M.E. & Chandra, S. (2015). Implementation Plan for the Control of Aquatic Invasive Species within Lake Tahoe. Lake Tahoe AIS Coordination Committee, July 31, 2015. Reno, NV. 52 pp. http://dx.doi.org/10.3391/mbi.2015.6.4.01suppl

Wittmann, Marion E., Chandra, S., Reuter, J. E., Caires, A., Schladow, S. G., & Denton, M. (2012). Harvesting an invasive bivalve in a large natural lake: species recovery and impacts on native benthic macroinvertebrate community structure in Lake Tahoe, USA. Aquatic Conservation: Marine and Freshwater Ecosystems, 22, 588–597. doi:10.1002/aqc.2251

Wittmann, Marion E., Chandra, S., Reuter, J. E., Schladow, S. G., Allen, B. C., & Webb, K. J. (2012). The control of an invasive bivalve, Corbicula fluminea, using gas impermeable benthic barriers in a large natural lake. Environmental Management, 49(6), 1163–1173. doi:10.1007/s00267-012-9850-5

Supporting Partners

The Martis Fund, a collaborative project of Martis Camp landowners, DMB/Highlands Group (the developers of Martis Camp), Mountain Area Preservation (MAP), and Sierra Watch. (See martisfund.org for more information)

The Community Impact Fund, Ashley Quinn Fund & the Foresight Fund held at the Tahoe Community Foundation

Additional thanks to the Tahoe Regional Planning Agency for providing specimens for studio filming

Aquatic Invasive Species