Reproductive activity of Bombina pachypus from southern Italy

Seasonal changes in gonadal morphology, secondary sexual characters, and pl asma sex steroids were studied in male and female Bombina pachypus from sou thern Italy. In this species, frogs are active and breed from May to Septem ber. During the long breeding season, sperm were always present in the test es. However, the testes did not always exhibit all stages of spermatogenesi s. In July, spermatogenesis did not exceed the stage of spermatocyte II whe reas in August it included all stages. It is possible that males use sperm originating from the preceding fall for the earliest spring matings. Throug hout the breeding season, females showed many follicles in advanced or comp lete vitellogenesis and many atretic vitellogenic follicles. Postovulatory follicles, if any, were rare. Females laid few eggs at each oviposition. Co ncerning male sex steroids, testosterone was at comparable levels from May to September, and it markedly decreased in October. In females. wide variat ions in plasma estradiol and progesterone levels were observed only in indi viduals with postovulatory follicles Emphasis is given to the prolonged and opportunistic reproductive activity of this species.