The Tendencies of Fish Selection Development in the Terms of Tolerance

In any period of economic development of a country, food production in the agricultural complex, with fisheries incorporated in, is of paramount importance. Fish production seems to be the most economically profitable protein raw material. However, pisciculture and fishing development has some problems under up-to-date conditions.Increased stocking fish densities in aquaculture and their high concentration in small areas influenced fish physiological state, their viability and resistance to diseases at artificial reproduction. Environment pollution decreases fish resistance to different diseases agents, promotes accumulation of toxic matters in fish tissues.Works are reviewed concerning resistance (tolerance) of natural and artificial fish populations to environmental factors¿ affect including pollution. Improvement possibility for aquaculture objects has been shown owing to selection works conducting.