Sciences marines : recherche et développement

Abstrait

Ecological, Biological, Behavioral and Genetic Adaptation to Xeric Habitats of Triturus Vittatus Vittatus (Urodela) on the Southern Border of its Distribution

Gad Degani

In the present mini-review, the results and unpublished data that were collected on Triturus vittatus vittatus in Israel on the southern border of its distribution, and on its adaptation to the Mediterranean semi-arid climate and to arid climate environments on the southern border of its distribution were presented. The contribution of the present paper is in building a model based on the results collected on the distribution, life cycle, behaviour and genetic variations among different populations in northern Israel down to the central coastal plains and near the desert of this species. More specifically, this model is based on the morphology, biology, behaviour and life cycle of T. v. vittatus adaptation. By considering these many parameters, one hypothesis was raised and is supported. The adaptation to and selection of habitats depends mainly on the terrestrial phase and less on the aquatic phases. There are various breeding places in all of the habitats, however, the newts are mainly used to winter ponds, many of which dry up in summer where the larvae can grow and complete metamorphosis. The adaptation of the breeding ponds is not under ecological conditions during larvae growth and complete metamorphosis, but the time of adult breeding and larvae growth occur year-round. The molecular genetic variation in the different areas support our hypothesis that climate is affected by altitude and proximity to the desert. During the life cycle the newts have two habitats aquatic and terrestrial and the adaption to terrestrial habitats is more affected on the newts distribution than the aquatic habitat. The quality model of fitness T. v. vittatus to extreme conditions was suggested.