Zebra mussels, species Dreissena polymorpha, are freshwater bivalve mollusks that typically have a dark and white (zebra-like) pattern on their shells, but may be any combination of colors from off-white to dark brown (hence the Latin name "polymorpha").
The History of the problem?
When was introduced into US? The Zebra Mussel was observed in North America in 1988 in Lake St. Clair ( a body of water that is on the border between Michigan, USA, ans Ontario, Canada ).
Effects of its nonnative environment
What environmental and damage has it caused? Zebra Mussel are know to have caused alarming declines in population of fish, Zebra Mussel are also damage of boat hulls, plug water systems used in boat motors, air conditioners and heads and cause navigation buoys to bind.