• Mississippi National River and Recreation Area

    Mississippi

    National River & Recreation Area Minnesota

Spectaclecase

(Cumberlandia monodonta) Say, 1829
A Specaclecase mussel
U.S. Army Corps of Engineers
Other Common Names:
None.
Habitat:
Found among boulders, in patches of sand, and cobble of large rivers with fast moving currents. In areas of slower moving current, can be found in gravels.
Length:
Up to 8 inches (20.3 cm).
Outer Shell Color:
Brown when younger shells, becomes darker to black as shell matures.
Inner Shell Color:
White.
Shell Thickness:
Thin in young, becomes thicker as the shell matures.
Shell Outline:
Longer than it is wide. Both the ends (farthest and closest to where the two halves meet) are round. The bottom of the shell is usually pinched or arched, but may sometimes be straight.
Shell Surface:
The shell ranges from being smooth to somewhat rough.
Scientific Description:
Shell brown or black, very elongate, usually curved, gaping slightly at both ends. Sexes alike. Incurrent papillae aborescent; excurrent aperture entire (fused) without papillae.
Similar Looking Mussels:
Host Fish:
Unknown.
Distribution:
Widely distributed but absent from many areas where it formerly occured.
Minnesota State Listing:
Threatened.
Federal Listing:
None.

Did You Know?

Headwaters of the Mississippi

The Mississippi River is approximately three feet deep at its headwaters at Lake Itasca and has an average surface speed of 1.2 miles per hour.