Potential distribution of the endangered spider Macrothele calpeiana (Walckenaer, 1805) (Araneae, Hexathelidae) and the impact of climate warming (In English)

摘要

The aims of this contribution are i) to identify major climate correlates of the distribution of Macrothele calpeiana (Walckenaer, 1805) in the Iberian Peninsula in order to predict its potential distribution; ii) to elaborate a hypothesis for the distribution of the spider in the Iberian Peninsula; iii) to identify suitable places for the species in both North Africa and the entire Mediterranean region through extrapolation of model predictions; and iv) to predict the impact of climate warming on the potential spider distribution. Generalized Linear Models were used to develop a potential distribution predictive model. Potential Iberian Peninsula distribution extends through a large part of Portugal where the spider has not been found. Historical factors are proposed as contributors to the absence of M. calpeiana from suitable areas. Existence of suitable conditions for the species in North Africa , and the absence of the genus there, favours the oriental origin of a Macrothele ancestor. Extrapolation to the Mediterranean region highlighted suitable territory in the Aegean area, where M. cretica Kulczynski, 1903, the other European Macrothele species, is found. Climate warming will negatively affect the existing Iberian M. calpeiana populations because it will reduce and fragment potential North African habitat. Confirmation of species presence, or absence, in much of Portugal and North Africa is a priority, as well as the development of phylogenetic studies of the genus to establish a solid hypothesis of Macrothele origin and dispersion history [ Acta Zoologica Sinica 53( 5 ): 865 – 876, 2007] .