ABSTRACT
Zebra and quagga mussels, Dreissena polymorpha and Dreissena bugensis, respectively, received much attention since their introduction to United States waterways in the 1980s. The zebra mussel signi‘cantly populated the eastern half of the United States over a10-year period. However, the quagga mussel was ‘rst discovered in the Colorado River system in 2007 and has since spread to other western waters.
