Studies on the Variability of Carp Populations in Ponds

Summary

The investigations on the variability of Polish carp reared in ponds proved that there exists a phenomenon called the stabilizing effect of variability. It consists in the initial diminution of the coefficient of variation and its later stabilization on certain levels. The diminution can be sometimes sharp. The diminution occurs from the first to the third year of growth. The stabilizing effect occurs from the fourth year of life, sometimes from the third. On the basis of the stabilizing tendency in the variability of carp populations a method of selecting spawners is proposed.