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What are zebra mussels and why should we care about them?

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Welcome to CoreFacts, where we're always short on time and big on science. I'm Jessica Robertson. Today's question is a good one.

What are zebra mussels and why should we care about them?

The zebra mussel is an invasive species and is very adaptable to new environments. It has the potential to inhabit most of the fresh waters of the U.S. and may impact a variety of native aquatic species and eventually entire ecosystems. They also have had a large economic impact already. Many power plants and water users have had to spend millions of dollars cleaning out zebra mussels from their facilities. In addition, more money has been spent on retrofitting facilities with devices to keep zebra mussels out and to monitor for them.

So, what is a zebra mussel? They are a type of mollusk, which also include a wide variety of organisms such as squids, octopuses, snails, oysters, scallops, and clams. Generally, zebra mussels live for four to five years and average about an inch in length. Mussels are also called "bivalves," which means they have two shells or valves. The zebra mussel gets its name because of the dark, striped pattern on each valve. Usually the shell is a light color, either tan or beige, with zig-zag stripes.

And now you know. Join us again every weekday for a new CoreFact. For other CoreFacts, or for CoreCast, our in-depth science podcast, go to If you'd like to have a question featured on our show, give us an email at or a phone call at 703-648-5600. Remember, long distance fees do apply.

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