Asian clam

Corbicula fluminea · Aquatic life

Whole animal · Photo: Samuel Brown / CC BY

InvasiveMollusk (mussel, clam, snail)

Also called Corbiculidae, Gold clam, Corbicula, Asiatic clam

State listing

Idaho: Prohibited invasive species
Oregon: Prohibited
Wyoming: Game and Fish aquatic invasive species

How to identify Asian clam

Small, thick, triangular to rounded clam usually under 1 inch
Strong, evenly spaced raised rings (ridges) on the shell
Yellow green to brown outside; light purple to white inside
Serrated teeth along the hinge

Similar species

Native fingernail clams are smaller, thin and smooth or finely ridged. Native mussels (floaters) are much larger and thin with no ridges.

Profile

Season	Present all year; spawns in spring and summer, sometimes again in fall.
Starts	Spawns when water is above about 60 F
Depth	Bottom sediments from shallow edges to deep water
How it spreads or reproduces	Self fertilizing, so one clam can start a population; larvae drift in water and are moved in bait buckets, live wells, sand and gravel
Habitat	Sand and gravel bottoms of rivers, reservoirs, canals and lakes; in the region mainly larger river systems such as the Snake and Columbia, and in eastern Wyoming reservoirs and rivers.

Why it matters in a lake

Clogs irrigation pipes, pumps, screens and cooling systems and can die off in large numbers that foul the water. Listed as a prohibited or aquatic invasive species in Idaho, Oregon and Wyoming, so do not move clams, bait or untreated water between waters.