| In some gonochoristic Teleosts, the sexual phenotype seems likely to be inverted in relation to the genotype, in some specific experimental conditions (cf. review by T. Yamamoto, 1969). Up to now, the best way to obtain such a result has been the administration of exogenous steroid sexual hormones in the fries' diet, before the normal gonad differentiation period. This way, T. Yamamoto (1953, 1958) obtained some total sexual inversions for the first time, either in the male direction, or in the female one, through the action of methyltestosterone and estrone in the Medaka (Japanese Killifish) Oryzias Latipes, then in the goldfish Carassius auratus (T. Yamamoto and T. Kajishima, 1968). |
