Ruffe

The Scientific name for the Euroasian Ruffe is // Gymnocephalus Cernuus. It has the average length of 4 to 6 inches and // spiny dorsal and anal fins  //. They are // olive brown coloring on the back and pale sides and is very easy to spot from the other fish. The Ruffe starts reproducing soon after the ice melts and until july. Ruffe mature in one to two years. Some males can even fully mature in a year or less. They produce rapidly and are even able to reproduce in their first year. Females can lay up to 45,000 to 90,000 eggs in one year. Due to their rapid reproduction they are successful invasive species. They also do not have any big predators to kill them off so they just keep reproducing. The Ruffe also can survive in a wide range of temperatures and habitats then its other competitors.   The Eurasian Ruffe dwells in the water of the great lakes such as Michigan, Wisconsin, and Minnesota and is spreading up Minnesota to the coast of Canada. They prefer fresh or brackish waters but adapt easily to their environments. The impact of this species is getting out of hand. The native species in the great lakes are rapidly declining in number and the Ruffe is taking over. It eats other fish eggs, competes against the benthos, and is competing with the other fish for food. The only positive is that they are a food source for a few species such as the heron, northern pike, and, yellow perch.  It doesn’t only affect the environment but also affects people. The owners of fisheries are suffering because some of there main commercial fishes are slowly declining in numbers, therefore making those specific fishes more expensive. The Eurasian Ruffe come from Europe and Asia area they were introduced by bringing ships in and out of the Ballast water in the Duluth Harbor in 1986. It is now mandatory if you catch the Ruffe while fishing you must kill and dispose of it properly. The UMESC scientists are conducting research on various types of chemicals that kill fish. They are attempting to develop chemicals that will kill Ruffe but leave other fish unharmed. Recent studies have explored the effectiveness of using existing registered chemicals to control Ruffe.