Race - hereditarily stable intraspecific groupings of fish, the emergence of which is due to the action of natural selection and certain habitat conditions; ensure the existence of the species. In ichthyology, there are geographical races (subspecies), which provide the species with an increase in the area of distribution, ecological races, which allow the species to develop more diverse habitats, seasonal races - development of the same biotope in different seasons of the year, temporary races that arise when changing environmental conditions.