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Mississippi National River and Recreation AreaThe hard-working Mississippi River spills over the Coon Rapids Dam.
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Mississippi National River and Recreation Area
Washboard
(Megalonaias nervosa) Rafinesque, 1820
A Washboard mussel
U.S. Army Corps of Engineers
Other Common Names:
Washboard; Bald-pate; Board.
Habitat:
Primarily large rivers with a good current; occasionally medium-sized streams in mud, sand, or gravel.
Length:
Up to 11 inches (27.9 cm).
Outer Shell Color:
Heavy brown or black.
Inner Shell Color:
White, often with purple or copper-colored blotches.
Shell Thickness:
Heavy.
Shell Outline:
Large. Looks somewhat rectangular (imagine a rectangle blown up, like a balloon).
Shell Surface:
Rough and wavy. Many V-shaped, pimple-like bumps on the beak (the point were the two shell halves meet), which develop into numerous wide ridges on the adult shell.
Scientific Description:
Very large, heavy brown or black subrectangular shell. Sexes alike. Beak sculpture extends onto disc as chevron patterned (V-shaped)tubercles, which develop into numerous wide ridges on adult shell. Sexes alike.
Similar Looking Mussels:
Host Fish:
Freshwater Drum (Sheephead), Black Bullhead, Gizzard Shad, Channel Catfish, Green Sunfish
Distribution:
May be common in its preferred habitat.
Minnesota State Listing:
None.
Federal Listing:
Threatened.
The mississippi river at night.  

Did You Know?
According to the Environmental Protection Agency, more than 50 cities rely on the Mississippi River for daily water supply.

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Last Updated: September 20, 2006 at 14:54 EST