Quadrula intermedia

Cumberland Monkeyface

FWS Focus

Overview

Characteristics
Overview

The Tennessee and Cumberland River basins historically contained the greatest diversity of freshwater mussels anywhere in the world.  Species specific to this area are referred to as “Cumberlandian”.  The Cumberland monkeyface is a Cumberlandian species restricted to the middle and upper Tennessee River system and has always been considered rare. It was placed on the federal threatened and endangered species list in 1976 as endangered. 

 

There are currently two populations of Cumberland monkeyface – one in the Powell River, crossing the Virginia-Tennessee state line, and one in the Duck River, entirely in Tennessee. Once known from Tennessee’s Elk River, it hasn’t been seen there in more than 40 years. Initial steps have been taken for it to be reintroduced to the Tennessee River in Alabama and the lower Holston and French Broad rivers, both in Tennessee. 

 

All surviving populations continue to be threatened by many of the same factors identified at the time of listing e.g., habitat fragmentation, loss, and alteration resulting from impoundments; operation of hydroelectric dams; mining; wastewater discharges; water withdrawal; competition and displacement by non-native species; and the runoff of silt and other pollutants from ground disturbance activities. 

Endangered Status for 159 Taxa of Animals, 41 FR 24062 24067 (June 14, 1976) 

Ortman, A.E. 1924. The naiad fauna of Duck River in Tennessee. American Midland Naturalist 9(1)18-62. 

Simpson, C. T. 1914. A descriptive catalog of the naiades, or pearly freshwater mussels. Bryant Walker, Detroit, MI, 3 vols, 1540 pp. 

U.S. Fish and Wildlife Service, 1982. Cumberland Monkeyface Pearly Mussel Recovery Plan. U.S. Fish and Wildlife Service, Atlanta, Georgia, 59 pp. 

U.S. Fish and Wildlife Service, 2021. Cumberland Monkeyface Five-Year Review. U.S. Fish and Wildlife Service, Asheville, North Carolina, 30 pp. 

Scientific Name

Quadrula intermedia
Common Name
Cumberland monkeyface
Cumberland monkeyface pearly mussel
Cumberland monkeyface (pearlymussel)
FWS Category
Clams
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Habitat

Characteristics
Habitat

The Cumberland monkeyface is associated with clean, fast-moving water with relatively stable cobble, gravel, and sand substrates free of siltation.  The mussel is usually found buried in the substrate in shallow riffle and shoal areas. 

U.S. Fish and Wildlife Service, 1982. Cumberland Monkeyface Pearly Mussel Recovery Plan. U.S. Fish and Wildlife Service, Atlanta, Georgia, 59 pp. 

River or Stream

A natural body of running water.

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

A medium-sized mussel roughly 2 inches in size, triangular to rectangular in shape with rounded corners.  The valves are flat and display a deep beak cavity.  

Bogan, A. am P. Panralee. 1983. Tennessee's Rare Mollusks, IN: Tennessee's Rire Wildlife, Final Report: TWRA, Tennessee’s Rare Wildlife: Final Report. TWRA, Tennessee Deparment of Conservation and Tennessee Heritage Program June 1979. Univ. of Tenn., Knoxville. 360 pp. 

Color & Pattern

The outer shell is a greenish yellow with spots, chevrons, zigzags, and rays, and is marked with numerous bumps and knobs.  The inner shell surface is white, straw-colored, or salmon.

Bogan, A. am P. Panralee. 1983. Tennessee's Rare Mollusks, IN: Tennessee's Rire Wildlife, Final Report: TWRA, Tennessee’s Rare Wildlife: Final Report. TWRA, Tennessee Deparment of Conservation and Tennessee Heritage Program June 1979. Univ. of Tenn., Knoxville. 360 pp. 

Characteristic category

Life Cycle

Characteristics
Reproduction

The lifecycle of Cumberland monkeyface is similar to other river mussels.  Males produce sperm which are discharged into the water and dispersed by currents.  Any downstream female of the same species obtains these sperm during filter feeding.  Fertilization of the female’s eggs by the sperm occurs within the gills of the female.  The fertilized eggs are retained in brood pouches, which are a modified section of the gills, to develop into larvae called glochidia.  Once developed the females release the glochidia into the water.  The glochidia must attach themselves to an appropriate fish host. After riding around on the fish for several weeks the glochidia will fall off the fish and settle on the bottom of river.  

Stein, C. B. 1971. Naiad life cycles: Their significance in the conservation of the fauna. IN: Rare and endangered mollusks (naiads) of the United States, USDI (Fish and Wildlife Service), Region 3, Federal Building, Fort Snelling, Twin Cities, MN. Pp. 19-25.  

Geography

Characteristics
Range

The Cumberland monkeyface is presently known only from the Duck and Powell Rivers.   

U.S. Fish and Wildlife Service, 2021. Cumberland Monkeyface Five-Year Review. U.S. Fish and Wildlife Service, Asheville, North Carolina, 30 pp.