Anodonta sp.

• Widely distributed from Baja California (Mexico) to Alaska

• Generally west of Rocky Mountains

• Great uncertainty about species identification

• 2 main clades (groups) of species are distinguished by the shape of the shell



Identification Tips:

• To 20 cm length, but 10-15 cm common
• Shells are thin and fragile
• No tooth on inside of shell at hinge
• Usually brownish in colour in Fraser Valley
• White fleshy nacre visible on shell margin when open
• 'Wing' at hinge may be present

Clade 1: Ratio of length to height of shell is less than 1.5
Clade 2: Ratio of length to height of shell is greater than 1.5

Life History:

• Rapid growing
• Sexually mature in 4 to 5 years
• Short-lived (10-15 years) compared to most mussels
• Found in high densities in mud or sand bottoms of lakes, ponds and slow moving streams
• Can occur in protected sites within fast rivers

Very SensitiveSomewhat SensitiveFacultativeSomewhat TolerantVery Tolerant

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