Find monkeyface information at Animal Diversity Web
Monkeyfaces are mussles with thick, round, or squarish shells. They get their name because the back edge of the shell looks like the face of a monkey. Their shells are green, light brown, or dark brown on the outside with green zig-zags. Younger monkeyfaces often have v-shaped markings, too. The shells also have bumps along the back edge. Inside, the shell is white on one side and iridescent on the other.
Monkeyface mussels live in the United States. They live in the Mississippi River, the Ohio River, the Tennessee River, and the rivers that drain into them. They used to be found in the Minnesota River, but are not found there anymore.
Monkeyface mussels live in medium and large rivers and streams. They mostly live mostly in places with sand and gravel or all gravel bottoms.
Monkeyface eggs develop into larvae called glochidia inside the gills of their mother. Females might have larvae in their gills from May to July. The females release the larvae, and they attach to the gills or fins of fish. They stick themselves on the fish and keep growing until they become juveniles. Later, they let go of the fish and settle on the bottom of the stream or river, where they grow into adults.
Monkeyfaces reproduce once a year in the spring. Males release reproductive cells into the water. Females take up these cells to fertilize their eggs.
Monkeyface mussels breed once yearly.
Monkeyface mussels breed from May to July in Minnesota.
Males release their reproductive cells into the water, and females downstream take them up to fertilize the eggs. The eggs hatch into larvae inside the gills of their mothers. They stay there for just a few months in the summertime. After a few weeks or months, they are released into the water and attach to a host fish. The larvae grow and develop attached to the host, and then let go and settle on the bottom.
Monkeyface larvae grow in the gills of their mother for a few months until they are released into the water.
Scientists don't know the lifespan of monkeyfaces in particular. Freshwater mussels can live 20 to even 100 years or more.
Monkeyface mussels mostly stay in the same place, but are able to move around on the bottom. They move using a muscle that they stick out from between their two shells.
Scientists don't know the size of the area where monkeyfaces live. Most mussels don't move very much after they grow into adults.
Mussels can probably respond to chemical signals that cause them to reproduce or other behaviors.
All mussels are filter feeders, meaning that they strain bits of food out of the water. They pull water through pores and into their gills using cilia, which look like tiny hairs. The bits of food get trapped in their gills and then mucous moves the food to their digestive system. This way, they eat on algae, bacteria, protozoans and other bits of plants or animals found in the water.
Freshwater mussels filter and clean the water where they live, and cycle nutrients through streams. They provide a surface for insects living in the water. Some of the fish their larvae attach to are sunfish, saugers, and bluegills.
No negative economic impacts are known for monkeyface mussels.
Mussels are used by researchers to test water quality. They don't move around much and live for a long time, so scientists can check their bodies for contaminants. When the water quality declines, the number of mussels might also decline. Mussels are also used for pearl oysters.
body parts are source of valuable material.
Monkeyface mussels are endangered in Ohio, threatened in Wisconsin and Minnesota, and under special concern in Arkansas. Their numbers might be decreasing because the water quality is getting worse.
Jordy Veit, Minnesota State University Mankato
Robert Sorensen, Minnesota State University Mankato
Renee Mulcrone, Special Projects
Catherine Kent, Special Projects
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