Freshwater Mussels Pacific Northwest - The Xerces Society

The Yukon floater is found in lakes and rivers of northwestern Canada and Alaska.
Yukon Floater
Anodonta beringiana Middendorff, 1851
Description 15,18
Size: Up to 8.25 inches.
Shape: Elliptical or elongate; L:H ratio near 2. Posterior narrowly rounded.
Laterally inflated over the anterior half of the shell. Valves thin but relatively
strong. No wings on the dorsal posterior slope.
Beaks: Inflated and raised above the hinge line. Beak sculpture consists of a
series of straight, irregular bars parallel to the hinge line.
Periostracum: Olive-green in juveniles to nearly black in older individuals.
Surface roughened by growth lines.
Hinge Teeth: None
Nacre: Lead-color to dull blue.
Range
A. beringiana is a northern species of the Yukon Territory, Alaska, Aleutian Islands,
and Kamchatka in eastern Asia 15,18 . It was historically thought to occur
in the Fraser and Columbia River systems of British Columbia 39 , but recent
records have not confirmed this. There are historical museum specimens of
A. beringiana from Oregon and Washington 47 , but the problems associated
with identifying western Anodonta based on shell morphology alone makes it
Freshwater Mussels of the Pacific Northwest 29