The genus Neomys is distributed throughout the Palearctic. Neomys teres is widely distributed in the Black Sea region, whereas Neomys anomalus is narrowly distributed in the West Palearctic region. Similarly, in Turkey, Neomys anomalus shows a wide distribution, but Neomys teres is distributed in the Black Sea highlands. These two species can be differentiated from each other morphologically and karyologically. N. anomalus and N. teres are different in terms of penis structure. The karyotypes of Neomys anomalus and Neomys teres are 2n = 52. The karyotype of the Neomys teres population in Turkey is not yet known. Neomys anomalus has adapted to terrestrial habitats while Neomys teres is a semiaquatic species. Neomys teres usually prefers the water's edges, especially small streams and creeks. Terrestrial invertebrates and aquatic invertebrates occur in the diet of both species.