A rounded to slightly elongated mussel. The posterior end is bluntly pointed in males. Females are shorter and may be nearly square.
The shell is thick, inflated, and smooth. Growth-rest lines produce ridges and dark-stained grooves. The outer layer of the shell is yellowish brown to chestnut in mature individuals. Broad, faint, green rays may cover the shell but are usually absent from adult shells.
Beaks (raised structures located externally near the hinge of the shell) are slightly raised above the hinge line. Beak sculpture, which is often difficult to discern, consists of six to ten fine, wavy, double-looped bars. The teeth (located dorsally within the shell) are large and well developed. The shell's inner lining (nacre) is white to a light salmon or pink and commonly salmon to orange in the beak cavities.
Adult length: 3 to 5 inches.
In Missouri, the pink mucket lives primarily in the Meramec, Gasconade, and Black rivers, and stretches of the Osage River.
Habitat and Conservation
Pink muckets live in the large stream reaches where flowing water covers beds of cobble, gravel, and sand. The depth of the water can vary from one inch to five feet deep. Because mussels are so intimately connected with their aquatic environment, drawing water in and out of their bodies, they are extremely sensitive to pollution and changes in water quality. Conservation efforts include habitat protection and improvement, and zebra mussel control.
Food
Algae, bacteria, and fine particles of decaying organic matter; extracts nutrients and oxygen from water drawn into the body cavity through a specialized structure called the incurrent siphon; sediment and undigested waste are expelled through the excurrent siphon.
Status
Listed as endangered by both the Missouri Department of Conservation and the U.S. Fish and Wildlife Service. Current threats include loss of habitat, competition from exotic zebra mussels, and overharvesting and illegal collection.
Life Cycle
Under certain conditions, males release sperm directly into the water. Females living downstream siphon the sperm into the gill chamber, where eggs are fertilized. The eggs mature into larva, which eventually discharge into the water and attach to a host fish. Eventually, the tiny mussel breaks away and floats to the bottom of the stream. Each mussel species parasitizes only certain species of fish. Black basses and walleye are the host fishes for pink muckets.
Human Connections
In the late 1800s and early 1900s, the Midwest had a flourishing industry based on the making of buttons from the shells of freshwater mussels. That industry has collapsed, but today our plastic buttons often are manufactured to resemble shell.
Ecosystem Connections
A diverse group of animals prey on mussels, including muskrat, mink, raccoon, fishes, turtles, and water birds.
