Ovarian activity and reproduction in the frog, Rana esculenta

摘要: Rana esculenta specimens were collected, during the last 13 years, in well-defined areas around Naples. The annual ovarian cycle shows distinct phases of recrudescence (starting September; vitellogenesis), breeding (late March-early July; egg deposition and active oogenesis) quiescence (July-August; no follicular growth). Previtellogenic follicles are recruited for vitellogenesis early September between two successive ovulatory waves. Breeding congregations generally formed after a heavy rain fall eggs laid standing waters, temporary or permanent. A maximum three clutches is produced season, at roughly monthly intervals. All mature females reproduce to some extent. Ovarian weight clutch size positively correlated body weight. Depending upon size, potential ranges from 1000 3500 first wave ovulation it notably smaller wave(s) ovulation. Egg masses tadpoles left unprotected mortality high. life fertilized completion metamorphosis 2 months oogenesis ovary starts larva before onset metamorphic climax. Young hatching may reach sexual maturity breed May following year; those require nearly 20 maturity. importance endocrine exocrine factors regulation activity reproduction discussed.