SPECIES ID / Invertebrates

Mussels

Western Pearlshell

Margaritifera falcata

• Found from California to southern British Columbia west of Rocky Mountains

• Isolated populations in Oklahoma

• In decline across much of its range

 

 

Phylum:Mollusca
Class:Bivalvia
Order:Unionoida
Family:Margaritiferidae

Identification Tips:

• Thick, dark shell
• Tooth-like protrusions form interlocking hinge
• to 15 cm

Life History:

• Prefer fast flowing rocky-bottom streams
• Burrower, most of the population is typically under the surface
• Larvae are parasitic on gills of salmonids

POLLUTION TOLERANCE
Very SensitiveSomewhat SensitiveFacultativeSomewhat TolerantVery Tolerant
  SomeMost 

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Primary Information Source:
Voshell, J. Reese. 2002. A Guide to Common Freshwater Invertebrates of North America. McDonald and Woodward Publishing Company. Blacksburg, Virginia.