THE REGULATION OF THE REPRODUCTIVE CYCLE IN PODARCIS S. SICULA RAF. (REPTILIA LACERTIDAE): INFLUENCE OF THE REFRACTORY PERIOD ON THE SPRINGTIME TESTICULAR ACTIVITY

SUMMARY From the middle of the refractory period, adult males of Podareis s. sicula Raf. (Reptilia Lacertidae) were treated with different photothermal regimes: 28 °C, combined with darkness, short or long photoperiods. The treatments were short (21–41 days) and long (exceeding 10 months). In both cases, in spring, recrudescence of testes occurred early after long photoperiods and was markedly delayed after darkness. In the latter case, moreover, the summer crisis is remarkably anticipated as compared to the controls. High temperatures, combined with short photoperiod, induce limited stimulatory effects on spermatogenesis with a poor development of the secondary sexual characteristics. A comparison between the results obtained from short and long term experiments clearly show that the autumnal refractory period is of fundamental importance in the regulation of the reproductive cycle of Podareis s. sicula. In fact, during this period, the gonadal activity is « programmed » and pre-arranged for the next spr...