As many as 10,000 zebra mussels have been found on one unionid. Perched atop the posterior of the unionid shell, they remove food from the water before it can reach the unionid, remove male gametes before they can encounter a female, and result in the beaching of unionids during storms. Most of the unionids in western Lake Erie have been extirpated by these exotics. Largely a lake species, it may not do well in running rivers. How much of our already stressed unionid fauna will be eliminated by zebra mussels is unknown, but many experts fear the worst.
Freshwater mussels are one of North America's main claims to fame in terms of natural history.
I have a creek just twenty miles away from where I sit that contains more species of mussels than the entire continents of Europe and Australia combined. It is a resource and a heritage that is rapidly slipping away. The author wishes to thank Dr. David Stansbery, Ohio State University Museum of Zoology, Columbus, for permission to photograph many of the specimens used in this article. This is an official COA Conch-Net Web Page hosted by the Academy of Natural Sciences, Philadelphia. This page has been accessed 7103 times since 19 October 1996.