Results of investigations on induced gynogenesis and polyploidy in common carp are presented. The main part of the experiments dealt with ''temperature shock method'' optimization with emphasis on precise heat shock (h.sh.) timing during the 2nd meiotic division and the 1st cleavage. Time of shock initiation was expressed in relative unit of embryological age (τ0) for standardization of this parameter. Absolute time for shock initiation after insemination was calculated from one (τ0) duration at a pre-shock water temperature of 20oC (29.4 min) or 24oC (20.4 min). According to 2n-gynogenetic and polyploid larvae production, optimal shock timing corresponds to 0.15 (0.10-0.25) τ0 and 1.5 (1.4-1.6) τ0 in the 2nd meiotic division and the 1st cleavage (respectively), independently of pre-shock water temperature. Thousands of meiotic gynogenetic and triploid larvae (h.sh.: 39-39.5oC for 2-2.5 min at 0.10-0.20 τ0) and mitotic gynogenetic and tetraploid larvae (h.sh.: 39.5-40oC for 2-2.5 min at 1.4-1.5 τ0) were obtained in Israeli common carp Dor-70.
Results of investigations on induced gynogenesis and polyploidy in common carp are presented. The main part of the experiments dealt with ''temperature shock method'' optimization with emphasis on precise heat shock (h.sh.) timing during the 2nd meiotic division and the 1st cleavage. Time of shock initiation was expressed in relative unit of embryological age (τ0) for standardization of this parameter. Absolute time for shock initiation after insemination was calculated from one (τ0) duration at a pre-shock water temperature of 20oC (29.4 min) or 24oC (20.4 min). According to 2n-gynogenetic and polyploid larvae production, optimal shock timing corresponds to 0.15 (0.10-0.25) τ0 and 1.5 (1.4-1.6) τ0 in the 2nd meiotic division and the 1st cleavage (respectively), independently of pre-shock water temperature. Thousands of meiotic gynogenetic and triploid larvae (h.sh.: 39-39.5oC for 2-2.5 min at 0.10-0.20 τ0) and mitotic gynogenetic and tetraploid larvae (h.sh.: 39.5-40oC for 2-2.5 min at 1.4-1.5 τ0) were obtained in Israeli common carp Dor-70.