Arctic cisco (Coregonus autumnalis) is an anadromous species of freshwater whitefish that inhabits the Arctic parts of Siberia, Alaska and Canada. It has a close freshwater relative in several lakes of Ireland, known as the pollan, alternatively regarded as conspecific with it, or as a distinct species. The freshwater omul of Lake Baikal, formerly considered a subspecies Coregonus autumnalis migratorius of the Arctic cisco, has no close genetic relationship to it and is now classified as a separate species, Coregonus migratorius.