Farming of the Juvenile Narrow-clawed Crayfish (Astacus leptodactylus) in Cages and Ponds in Polyculture With Fish in the Heated Waste Water of the Thermal Power Plantf

Abstract

Experimental research has been carried out on fanning of the narrow-clawed crayfish larvae in ponds and cages in the TPP waste water. It was shown that farming in such conditions during the first vegetation period was more effective, than in water bodies with natural temperature regime. In ponds in polyculture with fish crayfish summerlings reached 4.4-4.6 cm length and 2.69-3.34 g mass; when grown in cages with natural forage resources - 3.4-3.7 cm and 1.25- 1.53 g, accordingly. Survival rate in the ponds amounted to 2.9-3.0%, in cages - 22.0-37.3%. Density of seeding should be about 70 specimens/m2. Cages of the open-air type have been recommended.