The tench or doctor fish (Tinca tinca) is a fresh- and brackish-water fish of the cyprinid family found throughout Eurasia from Western Europe including the British Isles east into Asia as far as the Ob and Yenisei Rivers. It is also found in Lake Baikal. It normally inhabits slow-moving freshwater habitats, particularly lakes and lowland rivers. In Germany, the tench is called Schlei.