Brown trout Salmo trutta fario is a subspecies of Sea trout Salmo trutta trutta, so it means that sea trout and brown trout belong to one species. In Latvian language Sea trout is called “Taimiņš” while in English and German it is called Sea trout thus showing that sea trout and brown trout are related. However, in Russian by word “taimeņ” is meant completely different fish species, which is not recorded in Latvia. Sea trout is an anadromous fish which spends most of its life in sea but in a river it spends first years of its life and comes back to spawn. Brown trout spends all its life in inland waters and does not do any long journeys. Genetic analysis shows that their gene pools are very similar. Besides, salmoniformes may inbreed however here we can talk only about similar forms of one species.