Ecological Observations on Chioglossa lusitanica (Caudata, Salamandridae)

Abstract

AbstractDuring 1977 and in October 1978 fieldwork was carried out on the Golden-striped Salamander (Chioglossa lusitanica) in the surroundings of Porto (Portugal). The occurrence of C. lusitanica appears to be limited to the northwestern part of the Iberian Peninsula; its distribution is well defined by the region with a precipitation of more than 1000 millimeters per annum and not exceeding 1500 meters altitude. Here it leads a nocturnal and secretive life along small streams in hilly and mountainous terrain. In autumn, the adults meet on their mating-sites, observations on the mating process conform with data already available. Oögenesis takes place in summer. A positive relation was found between the length of the female and its fecundity. C. lusitanica can autotomize its tail, which can regenerate completely. It was found that oögenesis proceeds at the expense of tail-regeneration. Egg-deposition takes place in September, October and November, the larvae hatch after six to nine weeks. Metamorphosis takes place from the beginning of summer onward. Some larvae postpone metamorphosis until next season, having spent two winters in the water. Adults spend the summer in hidden places and remain largely inactive. It was found that with the drying up of the brooks a part of some populations migrated to summer-refuges such as dams and deserted mine galleries, thereby sometimes covering long distances. These refuges may also serve as a place for copulation and for egg-deposition. Migration-patterns in the populations under study were markedly different, largely depending on the availability of resorts and summer-refuges. Juveniles lead a live less nocturnal than the adults. Furthermore they show a stronger tendency to stay close to the brook and to stay there in summer. The population-density along one of the brooks investigated was estimated at four to five adult specimens per section of one meter in length. Water withdrawal presents a serious danger to certain populations.