The European mink (Mustela lutreola), also known as the Russian mink, is a semiaquatic species of mustelid native to Europe.It is similar in colour to the American mink, but is slightly smaller and has a less specialised skull. Despite having a similar name, build and behaviour, the European mink is not closely related to the American mink, being much closer to the European polecat and Siberian weasel (kolonok). The European mink occurs primarily by forest streams unlikely to freeze in winter.