Key to Aquatic Macroinvertebrates in Utah - Large Mussels/Clams
There are two families of large mussels native to Utah, Margaritifieridae and Unionidae. The family Corbiculidae can also be found in Utah, but is a non-native mussel.
Corbiculidae (Asiatic Clam, INASIVE)
Description: Thick, oval shell. Concentric striae feel rough when scratched. Length 10-20 mm, up to 50 mm. Yellow, green, or brown in color.
Habitat: Burrows in sediment of freshwater lakes and rivers. Corbiculidae has been collected throughout Utah from Lake Powell to Box Elder County
Margaritiferidae (Western River Pearl Mussel)
Description: Shells are thick, heavy, and typically oblong. Shell striae are concentric. Length to 160 mm, Height to 70 mm, Diameter to 40 mm. Shell color is brown, black to olive green.
Habitat: Historically occurred in streams in the Wasatch Mountains. This family has not been collected in Utah since 1930. Is common in the Snake River drainage and the Humbolt River basin.
Unionidae (Freshwater Mussel)
Description: Shells vary from thick to thin. They are generally elongated and never round. Length to 100 mm, Height to 60 mm, Diameter to 35 mm. Shell color is green, yellow or brown.
Habitat: Two genera occur in Utah - Anodonta andGonidea angulata. They are found in large rivers and reservoirs in the Great Basin.