Lampreys belong to the family Lampreys of the order Lampreys.
It is found in northeast China, Europe, northern Asia, Korea, Japan and North America. Its body is slender, eel-shaped, and its skin is bare and scaleless; The eye is sensitive to light; The inner ear has two semicircular canals, which are bisexualism. Its early habitat in the sea, as they grow up to swim to freshwater rivers to spawn.