© Bruce McNitt/Panoramic Images (Virginia)
Appalachian Monkeyface Pearly Mussel
The Appalachian Monkeyface Pearly Mussel is a medium-sized mussel measuring about 2-3/4 inches. It is a bivalve, with its outer shell layer or periostracum, being yellow-green to brown in color with small raised greenish triangles. The shell is heavy and has numerous small tubercles on the anterior and behind the beak; the raised portion of the top of the shell. The nacre, or interior layer is composed of shingle-like crystals of calcium carbonate, is white on the monkeyface, and its beak cavity is deep. This lustrous interior is what is known as mother-of-pearl.
In Virginia, remnant populations exist in parts of the Clinch and Powell rivers.
This mussel inhabits shallow riffles, runs, and shoal areas of fast-flowing headwater streams with rubble, gravel, or sandy bottoms relatively free of silt. At one time its population was thought to be widespread in the Tennessee River drainage, but dams, pollution, and siltation have been major contributors to their demise.
Mussels are filter feeders, feeding on detritus, bacteria, phytoplankton, diatoms, zooplankton, algae and protozoa. The gills move the small food particles to the mouth.