(Toxolasma parvus) Barnes, 1823
A Lilliput mussel

U.S. Army Corps of Engineers

Other Common Names:
Found in a variety of locations and conditions such as mud, sand or fine gravel in ponds, lakes, and creeks as well as large rivers.
Up to 1.5 inches (3.8 cm)
Outer Shell Color:
Ranges from dark green to brown to dark brown without any rays.
Inner Shell Color:
Silvery or bluish white and exhibits rainbow colors.
Shell Thickness:
Moderately thick.
Shell Outline:
Shell is small and elliptical with both of the long ends being round.
Shell Surface:
Has a cloth-like texture.
Scientific Description:
Juvenile shell beak sculpture includes several parallel ridges sloping away from the dorsal margin. Sexes may differ, with female more inflated and rounded postbasally, with caruncle. This beak sculpture is unique among Upper Mississippi River mussels and is not easily eroded. Caruncles are also unique and are present in most specimens suggesting that the Lilliput is hermaphroditic (exhibiting both male and female features in a single animal). Uncertain historical record due to tendency of overlooking this tiny mussel. May be mistaken for young of other species.
Similar Looking Mussels:
Purple Lilliput, Texas Lilliput, Little Spectaclecase.
Host Fish:

Green sunfish

Widespread and locally abundant.
Minnesota State Listing:
Federal Listing:

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