Gynogenesis occurred in eggs of grass carp (Ctenopharyngodon idella) treated with X-irradiated milt from goldfish (Carassius auratus). Gynogenetic offspring were females, which indicates functional female homogamety in grass carp. Five of these gynogenetic fish were used as an egg source for a second generation of artificially gynogenetic fish. The percentage yield in this second generation was about the same as in the first, which suggests that the tendency to become diploid is not strongly heritable