• Mississippi National River and Recreation Area


    National River & Recreation Area Minnesota


(Lasmigona costata) Rafinesque, 1820
A Fluted-Shell mussel
K.S. Cummings, Illinois Natural History Survey
Other Common Names:
Sand mussel, squawfoot.
Lives in sand, mud, or fine gravel in medium to large rivers where the flow of water are slow to moderate.
Up to 7 inches (17.8 cm).
Outer Shell Color:
Green to yellowish brown in younger individuals and becomes chestnut or dark brown as the shell matures.
Inner Shell Color:
White, bluish white, and often salmon-colored.
Shell Thickness:
Moderately thick.
Shell Outline:
Longer than wide and slightly inflated. Both the two ends of the mussel are sharply curved. The top and bottom are also both straight to slightly curved.
Shell Surface:
Shell is smooth on end closest to where the two halves meet and contains noticeable ridges on the opposite end.
Scientific Description:
Yellow, green, or brown shell often with green rays. Shell elongate, subrectangular and compressed. Ridges or "flutes" on posterior scope.
Similar Looking Mussels:
Host Fish:
Widespread but relatively uncommon.
Minnesota State Listing:
Special Concern
Federal Listing:

Did You Know?

Lock and Dam Number 1 from a long distance.

At Lake Itasca, the elevation of the Mississippi River is 1,475 feet above sea level. It drops to sea level at the Gulf of Mexico. More than half of that drop occurs within the state of Minnesota.