Characteristics of populations of narrow-clawed crayfish Pontastacus leptodactylus in three Belarusian lakes of the Baltic sea catchment area

The population characteristics of narrow-clawed crayfish were studied in three Belarusian lakes of the Baltic Sea catchment area. The life history of crayfish is 7 years. The number of larvae I, produced by all females of the population in late spring – early summer is the highest in eutrophic lake Bobrovichskoe – 26.37 ind./m2, the lowest number of larvae I is in mesotrophic lake Ginkovo – 7.09 ind./m2. The number of individuals that survive the transition period from larvae I to the age of one year is 2.80 ± 0.46%, to sexual maturity at the age of 3 years – 0.73 ± 0.15% of crayfish individuals. In the considered populations, the annual survival rate of sexually mature females in the considered populations is 50.7 ± 1.53%. The average generation time is 4.03 ± 0.13 years.