Speckled Pocketbook

Lampsilis streckeri

Description

The speckled pocketbook is a thin mussel, with a dark-yellow or brown shell with chevron-like spots and chain-like rays. The shape of its shell is elliptical, about 3.1 in (80 mm) long. Female mussels have a broader shell that is more evenly rounded in the back. There is a minnow-shaped mantle flap with a small pigment spot and five triangular markings.

Behavior

The life history and reproductive cycle of the speckled pocketbook are not known, but are presumed to be similar to those of other freshwater mussels. During spawning, the males discharge sperm into the water, and females siphon them into their gills where their eggs are fertilized. The fertilized eggs develop into larvae that are discharged into the water column, where they may attach to a fish host. The parasitic larvae encysts and develops into a juvenile mussel, after which it drops off the fish and settles to the bottom to adopt the sedentary adult lifestyle. The specific host fish for the speckled pocketbook is not known. The mussel filter-feeds on algae, tiny zooplankton, and suspended organic matter.

Habitat

The speckled pocketbook occurs in coarse to muddy sand in water depths up to 1.3 ft (0.4 m). It occurs in well-oxygenated water with a steady flow.

Distribution

The speckled pocketbook is an endemic species that is restricted in range to the Little Red River, in Stone and Van Buren Counties, Arkansas.

Threats

The speckled pocketbook originally probably occurred throughout most of the Little Red River system. However, it lost most of its original habitat when the impoundment creating the Greers Ferry Reservoir altered most of the Little Red River through flooding and changes in hydrology, water chemistry, and temperature. Some of its habitat was also damaged by channel modifications for flood control undertaken by the U.S. Army Corps of Engineers. In the early 1990s, only a few hundred specimens of the speckled pocketbook were known from a 6-mi (10-km) reach of the Middle Fork of the Little Red River, between its confluence with Tick and Meadow Creeks. The rare mussel once also occurred in Archey and South Forks of that river, but these populations have disappeared. The only surviving population of the speckled pocketbook is threatened by intermittent water pollution from an unidentified source in the Tick Creek's confluence. Recent surveys have only found dead mussel shells, and no live animals, downstream of Tick's Creek, suggesting a pollution problem in the Middle Fork.

Conservation and Recovery

The surviving habitat of the rare speckled pocketbook must be conserved and protected from pollution and other damages. Its populations should be monitored, and research undertaken to determine management practices that could be used to improve conditions for the endangered mussel. Once its population increases, additional ones should be established by transplanting animals into suitable habitat elsewhere within its natural range. The apparent source of pollution to the Tick Creek's confluence should be abated, which would allow the habitat to recover and again become suitable for the speckled pocketbook. Archey and South Forks should also be restored as suitable habitat for this endangered mussel.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
http://southeast.fws.gov/

U. S. Fish and Wildlife Service
6578 Dogwood View Parkway, Suite A
Jackson, Mississippi 39213-7856
Telephone: (601) 965-4900
Fax: (601) 965-4340

References

U. S. Fish and Wildlife Service. 1990. "U. S. Fish and Wildlife Service, Division of Endangered Species, Species Accounts: Speckled Pocketbook Mussel(Lampsilis streckeri)." U. S. Fish and Wildlife Service, Endangered Species Program. (http://endangered.fws.gov/i/f/saf0z.html). Date Accessed: July 6, 2000.

U. S. Fish and Wildlife Service. 1989. "Endangered and Threatened Wildlife and Plants: Endangered Status for the Speckled Pocketbook (Lampsilis streckeri)." Federal Register 54 (38): 8339-8341.