Variação anual do sistema reprodutor de fêmeas de Bothrops jararaca (Serpentes, Viperidae)

The morphological changes of the ovary and oviduct of 238 tropical snakes Bothrops jararaca (Wied, 1824) were determined. The ovarian mass presented a remarkable decrease in October, after ovulation, staying in low levels from November to March, during the gestational period. From April to September, it increased because of the ovarian follicles maturation. A gradual increase in oviduct weight was observed from October to March due to stages of embryonic development. A significant difference was observed between right and left ovary weight, and oviduct length, independently of the months considered.