Sex-reversal of male Armadillidium vulgare (isopoda, malacostraca, crustacea) following andrectomy and partial gonadectomy

Evidence is presented for the first time for the complete sex-reversal of genetic males of the terrestrial isopod Armadillidium vulgare into functional females folloing partial gonadectomy. Fifth-instar males were used. The anterior half of their rudimentary reproductive organs along with the attached androgenic glands were removed. Six months later these animals formed oostegites and laid eggs, and when bred with normal males, produced only male offspring. These results show that in the absence of the androgenic gland, female sex characteristics differentiate and oogenesis occurs in genetic males.