Mississippi River Mussels

Winged Mapleleaf

Winged Mapleleaf (Quadrula fragosa)

Courtesy of INHS

Believe it or not, humans and freshwater mussels have had a long history together. From mussel shell tools, to buttons, to jewelry, mussels have played a big part in human society. Worldwide, there are roughly 500 distinct species of freshwater mussel. The North American continent has the most diverse population in the world, with around 300 species.

These unassuming mollusks have a very unique life cycle. To make it to adulthood, freshwater mussel larvae require a host fish to feed from for a short period of time. Many species have devised ingenious ways of attracting a host fish. Some grow lures that look like minnows, some spray their offspring at passing fish, and some even trap fish until their larvae have had a chance to attach to their hostages. The mussel larvae attach to the gills and fins of their host fish and feed off the fish's blood for a few weeks. After this period, they fall off and begin their quiet life on the river bottom. Check out our Mussel Introduction page for more general information.

Because mussels spend all of their time in the water, the health of mussels is intimately tied to the health of our rivers and streams. As river systems change by the introduction of dams, increased sedimentation, pollution, channelization, the introduction of non-native species to rivers, and a host of other factors, change also comes to the plants and animals that inhabit those environments. Many of these changes have not been good for native mussel populations. The Nature Conservancy estimates that 66% of mussel species in North America are at risk or already extinct. To put it another way, 2/3 of the 300 different kinds of mussels we should be able to find in North American lakes, rivers and streams are either declining or extinct. In Minnesota alone, 25 species of mussels are regarded as endangered, threatened, or of special concern.

But not all is gloom and doom for mussel populations. Recently, there have been some surprising and encouraging finds of rare species thriving where none were expected. As riverside environments are restored, mussel populations seem to be rebounding. New techniques for reproduction and re-introduction of mussel species to particular habitats are finding a ready and interested audience.

These pages consist of mussels that have been found in the 72-mile stretch of river within the boundaries of the Mississippi National River and Recreation Area, along with species that we hope to find and, unfortunately, some that once populated these waters but will not likely be seen again. The National Park Service is working with the Minnesota Department of Natural Resources to identify the kinds and numbers of mussels that make this part of the river their home.

Did You Know?