The aim of the study was to obtain information regarding the spontaneous formation of gynogens in ide, Leuciscus idus (L.). Oocytes obtained from orfe and activated with the milt of dace, Leuciscus leuciscus (L.), were used for the study. Several control groups were established to determine the quality of gametes and the quality of the diluted semen. Ploidy in the offspring was determined by analyzing the number of nucleoli in the cells. Spontaneous diploid individuals appeared in groups in which the biological quality of the oocytes was poor. The percentage of these individuals was not large, and the average was a maximum of 0.4%.
