FWS Focus

Overview

Characteristics
Overview

The snuffbox is an endangered species that is declining throughout its range due to habitat modification and destruction, sedimentation, and pollution. Despite this, it remains the most widespread and abundant member of the genus Epioblasma, of which the other members are now either extinct or severely imperiled.  All remaining species in this genus are also federally listed. 

Scientific Name

Epioblasma triquetra
Common Name
snuffbox
Snuffbox mussel
FWS Category
Clams
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Life Cycle

Characteristics
Reproduction

The is currently considered extant in 85 streams across its geographical range within the states of Alabama; Arkansas; Illinois; Indiana; Kentucky; Michigan; Minnesota; Missouri; Ohio; Pennsylvania; Tennessee; Virginia; West Virginia; and Wisconsin, USA and Ontario, Canada. Historically, the snuffbox occurred in at least 213 streams and lakes, as well as occurred in the states Iowa; Kansas; Mississippi; and New York. The species range has since been reduced to the upper Great Lakes sub-basin; the lower Great Lakes sub-basin; the upper Mississippi River sub-basin; the Ohio River System; the Cumberland River System; the Tennessee River System; and the lower Mississippi River sub-basin.

Lifecycle

The snuffbox has a complicated life history that is tightly linked to freshwater fishes. Fertilized eggs develop into larvae, called glochidia, which are held by the female. Glochidia, when released from the female, must come in contact with a passing fish and attach to the gills, fins, or body of that fish. During this parasitic stage, the mussel glochidia are relatively harmless to their fish host. The mussel-host fish relationship helps disperse a basically immobile creature (the mussel), within and between aquatic systems. Snuffbox are "host specific" in that their glochidia can only survive on a specific species of fish, primarily the logperch. If a glochidium attaches to a fish that is not a suitable host species, it will not survive. After several weeks, the glochidia free themselves from the host, drift to the substrate and begin their lives as juvenile mussels.

Lifespan

The snuffbox may live up to 25 years. They reach sexual maturity at around age 3.

Characteristic category

Habitat

Characteristics
Habitat

The snuffbox is an endangered species declining throughout its range due to habitat modification and destruction, sedimentation, and pollution. Despite this, it remains the most widespread and abundant member of the genus Epioblasma, of which the other members are now either extinct or severely imperiled. All remaining species in this genus are also federally listed. 

River or Stream
Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The snuffbox has a triangular, medium-sized shell. The species is sexually dimorphic, meaning males and females differ in appearance. The shell of the male has a narrow, shallow central depression or groove and the female's shell extends outward at one end. Males can grow to 70 mm with females being considerably smaller.

Color & Pattern

The snuffbox has a yellow, green or brown shell interrupted with green rays, blotches or chevron-shaped lines. The shell becomes darker and the interruptions less clear with age. The inside of the shell is white.

Characteristic category

Food

Characteristics
Food

The snuffbox feeds by using a siphon to filter small organic particles, such as bacteria, algae, and detritus, out of the water column and into their gill chambers.

Characteristic category

Behavior

Characteristics
Behavior

The snuffbox feeds by using a siphon to filter small organic particles, such as bacteria, algae, and detritus, out of the water column.

Geography

Characteristics
Range

The is currently considered extant in 85 streams across its geographical range within the states of Alabama; Arkansas; Illinois; Indiana; Kentucky; Michigan; Minnesota; Missouri; Ohio; Pennsylvania; Tennessee; Virginia; West Virginia; and Wisconsin, USA and Ontario, Canada. Historically, the snuffbox occurred in at least 213 streams and lakes, as well as occurred in the states Iowa; Kansas; Mississippi; and New York. The species range has since been reduced to the upper Great Lakes sub-basin; the lower Great Lakes sub-basin; the upper Mississippi River sub-basin; the Ohio River System; the Cumberland River System; the Tennessee River System; and the lower Mississippi River sub-basin.

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Timeline

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