Endangered Species
Clams are bivalve mussels that live in rivers. The Duck River is a habitat for many species of mussel. The pearl lining inside the dark shells of pearlymussels are the source for mother-of-pearl. Three species found in Tennessee are the riffleshell, tan, the monkeyface, cumberland (pearlymussel) and the wartyback, white (pearlymussel). These clams may be found as far north as Illinois and as far south as Alabama. All three of these species are on the federal endangered species list. Commercial demand for mussels historically led to the extinction and loss of many species in Tennessee.
Zebra Mussels
Zebra mussels (Dreissena polymorpha Pallas,1769) are known for their striped shells which usually have dark concentric rings and are pale near the hinges. Zebra mussels are exotic to the U. S. and native to the Black Sea, Caspian Sea and the Azov Sea. These invasive mussels are found in Tennessee and other parts of the U.S. and are believed to have been introduced to the waterways by a single commercial cargo ship traveling from the Black Sea. They invade water supply pipes and hydroelectric power plants, restricting water flow. They multiply and attach themselves to any surface. Zebra mussels also invade fire fighting equipment and home air conditioners.
Commercially Harvested Mussels
Of the 170 freshwater mussels found in Tennessee, only 10 species can be harvested commercially. Strict regulation of the species and size for harvesting is in place in Tennessee waters. The species available for harvesting are listed in the Tennessee Wildlife Resource Agency Mussel Report as the pink heelsplitter, washboard, river pigtoe, lake pigtoe, mapleleaf, southern (snootnose) mapleleaf, three ridge, elephant ear, ebony and monkeyface.The U.S. Fish and Wildlife Service states that certain monkeyface mussels are on the threatened and endangered species list.