What is "zebra mussel"

n. A striped mussel, (taxlink Dreissena polymorpha species noshow=1), originating in Russia.

n. inch-long mollusk imported accidentally from Europe; clogs utility inlet pipes and feeds on edible freshwater mussels [syn: Dreissena polymorpha]

The zebra mussel (Dreissena polymorpha) is a small freshwater mussel. This species was originally native to the lakes of southern Russia, being first described in 1769 by the German zoologist Peter Simon Pallas in the Ural, Volga, and Dnieper rivers. These mussels are still found nearby, as Pontic ( Black Sea) and Caspian species. However, the zebra mussel has been accidentally introduced to numerous other areas, and has become an invasive species in many different countries worldwide. They were invasive to the Great Lakes but in the 1990s, they invaded the Hudson River. They are commonly found on the bottom of ships and eat the algae that is food for fish. Without food, fish starve. Inspectors check ships for the mussels before they leave port. Scientists are trying to control the mussels.

Zebra mussels get their name from a striped pattern commonly seen on their shells, though it is not universally present. They are usually about the size of a fingernail, but can grow to a maximum length of nearly . Shells are D-shaped, and attached to the substrate with strong byssal threads, which come out of their umbo on the dorsal (hinged) side.