The Ruffe or pope (lat. Gymnocephalus cernuus) is a small member of the perch family found in temperate regions of northern Europe and Asia. It has been introduced into the Great Lakes of North America.
An adult ruffe is about five to six inches long. It never exceeds 10 inches in length, but is a very aggressive fish for its size. The ruffe mature quickly, in 2-3 years and have an average lifespan of 7 years. Ruffe consume a variety of different food and have very few predators because large, spiny dorsal fin likely distasteful to its predators and make them difficult for other fishes to eat.
Ruffe can very quickly become the most dominant fish in local areas because of their rapid reproductive and growth rates. A single ruffe female has the potential to lay from 130 to 200 thousands eggs annually.