The araneomorph spiders Loxosceles laeta and Scytodes globula have greater daily variations in preferred temperatures at twilight and during the night, which are set to the nocturnal activity rhythms of these species. For example in the mygalomorph high-altitude spider Paraphysa parvula the preferred temperature is similar to that of the lowland spider Grammostola rosea but while P. Preferred temperatures and critical temperatures of Chilean spiders vary among species and individuals and may be adjusted by phenotypic plasticity.

In this review we focus on body design, energetic, thermal selection, and water balance characteristics of some spider species present in Chile and correlate our results with ecological and behavioral information. These impose three main problems: (i) terrestrial habitats have large fluctuations in temperature and humidity (ii) the internal concentration of water is higher than the external environment in spiders, which exposes them continually to water loss and (iii) their small body size determines a large surface/volume ratio, affecting energy exchange and influencing the life strategy. Spiders are small arthropods that have colonized terrestrial environments. 3Departamento de Ciencias Biológicas Animales, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile.2Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.1Departamento de Medicina and Programa de Salud Ambiental, Escuela de Salud Pública, Facultad de Medicina, Universidad de Chile, Santiago, Chile.

Mauricio Canals 1 * Claudio Veloso 2 Rigoberto Solís 3

System shock 2 spiders