Zebra Mussel

Dreissena polymorpha

The zebra mussel is an invasive, non-native bivalve mollusk with D-shaped shells striped with dark- and light-colored concentric bands. Zebra mussels can grow to about 2 inches, but are usually less than an inch.

Where does the zebra mussel live?

Zebra mussels have been found in lakes, rivers and reservoirs in the central and eastern United States. They will attach to any solid underwater surface, including buoys, rocks, pilings, boat hulls and other mollusk shells.

In the Chesapeake Bay watershed, zebra mussels have been found in parts of Maryland, New York, Pennsylvania and Virginia.

What does the zebra mussel eat?

Zebra mussels are filter feeders.

• Water and food particles are brought in through a siphon and filtered by the mussel's gills.
• Particles not used by the mussel are ejected through a second siphon.

How does the zebra mussel reproduce?

Zebra mussels spawn once water temperatures warm to 54 degrees. They are prolific spawners; females can release more than one million eggs over a single spawning season.

• Free-swimming larvae can live in the water column for five days to three months. During this time, water currents easily transport larvae throughout river systems.
• Once zebra mussel larvae settle, they attach themselves to the bottom with strong, thin threads secreted from a gland on the foot.
• Young zebra mussels often settle on top of older, bigger mussels, creating large colonies.

Other facts about the zebra mussel:

• Zebra mussels typically live three to five years, with some living up to 15 years.
• Freshwater drums, yellow perch, sturgeon, crayfish and diving ducks all prey upon zebra mussels.