Ciclo reproductor y de cuerpos grasos en los machos de Lacerta monticola cantabrica. Comparación entre dos poblaciones situadas a diferente altitud

Abstract

Male reproductive and fat body cycles were studies both in a mountain and a lowland population of the lizard Lacerta monticola cantabrica. Specimens were collected at two localities in Asturias (Northern Spain): Vegadeo (100 m a.s.l.) and Aramo (1450 m a.s.l.). General patterns of spermatogenesis in both populations were similar, and agree with the mixed type proposed by Saint Girons (1963). Spermatogenesis and testicular growth start in August and spermiogenesis begins in early autumn; before hibernation (October) spermiogenesis ceases earlier in the mountain than in the lowland population. The culminative phase of spermatogenesis and the testis weight peak occur after the onset of spring activity; there is then a progressive decrease that lasts until the end of the female's ovulation cycle in July. Recrudescence of epididymides occurs mainly in late winter-early spring, with a pronounced development just after emergence from wintering; there is a delay in the epididymis peak of the mountain population. Both populations show an abrupt epididymal decline in the summer, between June and August. Fat bodies begin to increase in summer, just after the end of the reproductive period, reaching maximum weights in autumn prior to wintering. Pre-hibernation fat body weights for males at the two elevations are nearly the same (about 2% of body weight on average), but winter consumption is much larger in the lowland population in which there is some activity during this period. Fat bodies are not depleted at emergence and the remaining stores are utilized during the spring reproductive period, leading to minimum levels in June in both populations.