Key to Aquatic Macroinvertebrates in Utah - Small Clams

Picture Description Habitat


Asiatic Clam


Thick, oval shell.

Concentric striae feel rough when scratched.

Length 10-20 mm, but can grow up to 50 mm

Yellow, green, or brown in color.

Burrows in sediment of freshwater lakes and rivers.  Cobiculidae has been collected throughout Utah from Lake Powell to Box Elder County.


Zebra and Quagga mussel


Distinct triangular shaped shell, striped patterns.

Exotic species from Eastern Europe

up to 50 mm in length

Zebra mussels are not yet found in Utah, Quagga mussels can be found in Sand Hollow Reservoir


Fingernail Clam

Shells are thin, smooth, and generally oval.
Yellowgreen or white in color
> 25 mm in length, generally less than 10 mm

Found in nearly all aquatic habitats.

Back to my organism has a double shell