zebra mussel

from The American Heritage® Dictionary of the English Language, 4th Edition

• n. A small freshwater mussel (Dreissena polymorpha) with a usually striped shell, native to Eurasia but widely established since the late 1980s in the Great Lakes and other North American waterways.

from Wiktionary, Creative Commons Attribution/Share-Alike License

• n. A striped mussel, Dreissena polymorpha, originating in Russia.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• n. inch long mollusk imported accidentally from Europe; clogs utility inlet pipes and feeds on edible freshwater mussels