The slime covered, mottled brown ruffe is common along Finnish shorelines and inland waters, except for the northernmost part of Lapland. It likes staying at bottoms, at depths of two to 30 meters. At dusk, it searches for food in large schools at bottoms. Its diet consists of mosquito larvae, gastropods and isopods. When threatened, it spreads its spiky fins and gill covers, which usually make its predator, leave and seek an easier meal. Ruffe grows to about 15 centimetres in inland waters and slightly more in coastal areas. Many people have unpleasant memories of ruffe, because due to its spikiness it can stick tightly to the nets, and since it is slimy, it is difficult to disentangle it from the net. Ruffe’s meat is very tasty, but the small size and difficulty to handle it limit its use.