what is a zebra mussel?
The zebra mussel (Dreissena polymorpha) is a small, non-native mussel originally found in Russia. In 1988, this animal was transported to North America in the ballast water of a transatlantic freighter and colonized parts of Lake St. Clair. In less than 10 years, zebra mussels spread to all five Great Lakes and into the Mississippi, Tennessee, Hudson, and Ohio River Basins. Many inland waters in Michigan are now infested with zebra mussels. Only one lake was infested in 1992; today there are over 100. Zebra mussels are very successful invaders because they live and feed in many different aquatic habitats, breed prolifically (each female produces 1 million eggs per year), and have both a planktonic larval stage and an attached adult stage. Young zebra mussels are planktonic. They are the size of the diameter of a human hair and are invisible to the naked eye. Because young zebra mussels are so small, they are spread easily by water currents and can drift for miles before settling. Adult
Zebra mussels (Dreissena polymorpha) are freshwater bivalves (clams) native to the Caspian, Black, and Azov seas of eastern Europe. Since the zebra mussel’s initial discovery in the United States in 1988, this bivalve has quickly spread throughout the Great Lakes and Mississippi River Basin states. Reproducing zebra mussel populations currently occupy waters in or adjacent to 25 states and extend westward into Nebraska, Kansas, and Oklahoma. For more information on zebra mussels, how they are different from native species, and the damage they can cause, please see the zebra mussels section of our Web site.
The zebra mussel, scientific name Dreissina polymorpha, is a type of mollusk. The mollusk family also includes clams, snails, oysters, squid, and the octopus. Why should you care about zebra mussels? They are one of many invasive species that are disrupting the natural balance of our ecosystems. Zebra mussels are specifically causing problems in the Great Lakes and connecting waterways. Physical Description Zebra mussels are bivalves. This means they are composed of two shells, a left and right valve. They are small (about the size of a fingernail) ranging from one to two inches in length. The shells are triangular shaped and beige colored with brown stripes. This coloration explains why they are called zebra mussels. Extending from the shells are byssal threads. A zebra mussel can have up to 100 byssal threads. They are strong proteins strands that allow the zebra mussel to attach itself to just about anything in the environment including other organisms. The byssal threads are so str
Zebra mussels are small shellfish named for the striped pattern of their shells. They are typically found attached to objects or each other by threads underneath the shells. Zebra mussels are native to the Black, Caspian, and Azov Seas. Each Zebra Mussel spawns 40,000 to 60,000 eggs a year that float as microscopic plankton until they find a secure place to attach. How and where have they spread? By the late 18th and early 19th centuries, zebra mussels had spread to most all major drainages of Europe because of widespread construction of canal systems. They first appeared in Great Britain in 1824 where they are now well established. Since then, zebra mussels have expanded their range into Denmark, Sweden, Finland, Ireland, Italy, and the rest of western Europe. Zebra mussels were first discovered in North America in 1988 in the Great Lakes. The first account of an established population came from Canadian waters of Lake St. Clair, a water body connecting Lake Huron and Lake Erie. A rel
The Zebra Mussel, Dreissena polymorpha (Pallas 1771), is a small clam-like animal (mollusk) about the size of an adult’s fingernail. Its shell is shaped somewhat like a letter D with dark- and light-colored stripes, hence the name “zebra.” The Zebra Mussel is not native to the United States, but rather is native to the colder streams and rivers of Europe. It has been speculated that these mussels were introduced into the United States from the ballast, or waste water, of a European cargo ship traveling in the Great Lakes area.
