Missouri's Freshwater Mussels

Missouri's freshwater pearly mussels live in the bottoms of rivers and streams near you. They sit quietly in the water and never utter a sound. They offer culinary and cleaning services, without lifting a finger. (They don't have any.) They tell us if our water is clean enough for people and livestock to drink. They can live longer than most humans.

Nearly 300 species of freshwater mussels live in North America, approximately 65 of which live in Missouri waters. The iridescent whites, brilliant purples and beautiful pinks of the nacre lining the inside of freshwater mussel shells are as colorful as the common names of mussels--washboard, pimpleback, elephant ear, rabbitsfoot, ladyfinger and pink heelsplitter, to name just a few.

Freshwater mussels live throughout Missouri in a variety of aquatic habitats. Some species, like the giant floater, are widespread and likely to be found throughout Missouri. Other species, like the purple wartyback, may live in several regions but are found in greatest numbers in areas with particular physiographical characteristics. Four main types of these areas or "aquatic regions" are found in Missouri.

More commonly known as clams or shellfish, freshwater mussels have been an important source of food, tools, buttons and jewelry. Native Americans relied heavily on mussel meat during the winter months when other food was scarce. They carved mussel shells and shaped them into tools. They also made pottery and jewelry from the mother-of-pearl shell interior, also called nacre (nay-ker).

In the early 1900s, the only type of button available was one punched from the shell of a freshwater mussel. The button industry originated here in the Midwest because a rich mussel fauna existed in the Mississippi River. At the time, it seemed an unlimited resource, but as barge-loads of mussels were plucked daily from the river bottoms, mussels began to decline rapidly. The long-lived, thick-shelled commercial freshwater mussel species couldn't reproduce as quickly as they could be harvested. In the 1940s, however, plastic was invented. The shell button industry eventually folded, and the mussels began to recover.

It wasn't long, though, before humankind discovered another commercial use for freshwater mussel shells. The pearly white nacre of some North American mussel species makes excellent starting nuclei for what will eventually become cultured pearls. Small blanks are cut from shells, formed into beads and tucked into oysters. Because it is an irritant, the oyster lays down a thick coating of secretions over the mussel bead. After