This paper describes reproductive anatomy, female reproductive cycle, potential clutch size, seasonal activity, and sexual dimorphism of a population of the Amaral’s blind snake in southeastern Brazil. Females grow larger than males. Male testes are spermiogenic in early spring, when the sexual segment of the kidney is hypertrophied, and the ductus deferentia are packed with sperm. Mating likely occurs in spring and is therefore synchronous with spermiogenesis, which is considered the ancestral state of Squamata. After mating in spring, females may store sperm in their reproductive tract until late spring and early summer, when they ovulate and lay 3-5 eggs.
