Some aromatizable androgens when administered at high concentrations or for
extended periods produce what has been called Aparadoxical feminizationB ŽHackmann,
1971 . Paradoxical effects of steroid administration have been reported since then in .
many vertebrates, especially in fish but also in amphibia and reptilia Norris, 1987 . Ž .
Regarding the origin of paradoxical feminization, it was shown that aromatization of the