‘Post-sex differentiational’ sex reversal in the female common carp (Cyprinus carpio)
Gonadal plasticity after sex differentiation has been verified in the female common carp. One-year-old genetically controlled female (XX) carps were fed with Fadrozole, an aromatase inhibitor (AI), and the gonads were subjected to histological analysis. Testicular lobule-like structures and cysts of spermatocytes began to appear after 8 weeks of treatment, and spermatozoa were initially observed at week 16 and then spread to the whole gonad in some individuals by week 18. These observations show that sexual bipotentiality is maintained after sex differentiation in the ovary of the common carp.