Snuffbox Mussel

Common Name - Snuffbox Mussel

Category - Mussels and Clams

ScientificName - Epioblasma triquetra

Kingdom - Animalia

Phylum - Mollusca

Class - Bivalvia

Order - Unionacea

Family - Unionidae

Genus - Epioblasma

Species - triquetra


Description - Has two hinged halves to shell (bivalve); small solid shell with green rays or blotches; front end rounded; shell hump (umbo) swollen and slightly above hinge; female’s shell is smaller and more inflated, in proportion to its height, than male

Size - Male 2.4 in. (6.0 cm) long; female 1.9 in. (4.8 cm) long

Ecological Role - The snuffbox mussel is a filter feeder, extracting microscopic food from the water it takes in through its intake tube (siphon). Its natural predators include raccoons, turtles, otters, minks, muskrats, and some birds. The fish hosts for the glochidial stage are the logperch and the banded sculpin. The gills of the fish host provide nourishment and transportation for the glochidia.

Fun Facts - The snuffbox mussel is a biological indicator of stream health because it can not tolerate pollution or excessive siltation. It is one of the first species to disappear from a system when habitat changes occur. The snuffbox mussel is the only one of 25 species of the genus Epioblasma in the United States that is not listed on the Federal Endangered Species List. It is, however, on state endangered lists in Illinois, Illinois, Wisconsin, Virginia, and Michigan. It is threatened on Ohio and Tennessee’s lists, and rare on Missouri’s list.

Food - Decaying plant and animal material, floating microorganisms





Habitat - Clear, shallow riffles in medium to large rivers; swift current with gravel and sand substrate

Kentucky Distribution - Ohio, Green, Kentucky, Tennessee, and Cumberland Rivers

Life Cycle - Egg, larva, adult; larvae (glochidia) formed early September, released late May; glochidia held inside female’s gills through winter, then released to attach to the gills of a fish host; become free-living as adults

Life Span

Life Stage


Seasonal Changes


Status - Rare




What We Can Do


Diagnosis and Control

Interesting Facts

Contributed By - Guenter A. Schuster, Ph.D., Dept. of Biological Sciences, Eastern Kentucky University

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