Fat Pocketbook

[AR T&E Species Home]


To learn more about the life cycle and reproduction of mussels, click here.
For an interactive version, click here.

Learn more about Fat Pocketbook in the Recovery Plan (1989) and 5-Year Review (2012).

Fat Pocketbook (Potamilus capax)
Status: Endangered
June 14, 1976

For questions regarding the Fat Pocketbook, please contact Chris Davidson at chris_davidson@fws.gov or 501-513-4481.

Species Facts:
The fat pocketbook has a shiny, light tan to brown shell and no rays and can grow up to 5 inches in length. There is no pronounced difference between the males and females. It feeds like other freshwater mussels, filtering food particles out of the water column.

Reproduction is similar to other freshwater mussels, with parasitic larvae (glochidia) released into the water column to parasitize specific species of fish. Freshwater drum is the only known host fish, although 28 different species have been tested.

Habitat Summary:
The fat pocketbook prefers sand, mud, silt, and fine gravel bottoms associated with depositional areas of large rivers and ditches. This species occurs throughout its historic range in the Mississippi, Ohio, Wabash, and St. Francis Rivers. It is most abundant in the St. Francis River and larger streams and ditches that are tributaries to the St. Francis River in Arkansas.

Why is it Endangered?
Habitat loss, fragmentation, and alteration through impoundments and channelization are the primary causes for the decline of the fat pocketbook. Fragmentation also increased population vulnerability to degraded water quality from land use (logging, farming, mining, development, etc.) or localized threats (droughts, chemical spills,etc). There is some concern over the effect of non-native zebra mussels, as they compete for food and space.

Captive propagation, reintroduction, and tracking efforts have been somewhat successful. Young mussels have been found in most sites in the St. Francis River drainage and some other rivers within the range, indicating recruitment is occuring. Data suggests that fat pocketbook have been increasing in abundance within the St. Francis, Ohio, and Lower Mississipii Rivers and some of their tributaries.

For more information on Fat Pocketbook recovery, check out the Recovery Plan (1989) and 5-Year Review (2012).

Range in Arkansas:

Arkansas Field Office
110 S. Amity Road
Suite 300
Conway, AR 72032

501/513 4470 (v)
501/513 4480 (f)

Last Updated: December 30, 2015

DOI |USFWS | USA.gov | Privacy | FOIA | Webmaster

FWS Southeast Region