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Pink Mucket

Lampsilis abrupta
Family: 
Unionidae (freshwater mussels) in the phylum Mollusca
Description: 

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-colored 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.

Size: 
Adult length: 3 to 5 inches.
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.
Foods: 
Water-borne nutrients such as diatoms and other algae, protozoans, plant and animal debris and other tiny particles are drawn into the body of the mussel via the incurrent siphon. The nutrients are trapped by mucus in the mussel's gill and are swept into the mouth via cilia. Excess water, carrying indigestible and waste materials, flows out the excurrent siphon.
Distribution in Missouri: 
In Missouri, the pink mucket lives primarily in the Meramec, Gasconade, and Black rivers, and stretches of the Osage River.
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. Scientists don’t know which fish species host 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.
Shortened URL
http://mdc.mo.gov/node/5080