Ruffe, << ruhf, >> is a small freshwater fish that is a major pest in North America. Ruffe are native to Europe and Asia. But they appeared in the Great Lakes of North America in the 1980’s and quickly became plentiful. Their explosive growth threatened the food supply of many fish native to the Great Lakes. Ruffe further endangered these native fish by eating the fishes’ eggs and larvae (young).
Ruffe grow up to 10 inches (25 centimeters) in length and have a drooping, scaleless head. Their bodies are brownish-green in color on the back and yellowish on the belly. Sharp spikes stick out of both the dorsal (back) fin and the bones that cover the gills. Ruffe live in lakes and slow-moving rivers. In addition to eggs and larvae of other fish, the ruffe’s diet includes a variety of insects and shellfish.
Ruffe were first discovered in Lake Superior in 1987. Ships probably transported ruffe larvae from Europe to North America. The larvae may have been trapped in the ships’ ballast (water kept in the hold of a ship to stabilize the vessel). Once the ships reached Lake Superior, they unintentionally released the young fish with the ballast.
