Thermal physiology of three sympatric and syntopic Liolaemidae lizards in cold and arid environments of Patagonia (Argentina)

DURAN, FERNANDO; KUBISCH, ERIKA; BORETTO, JORGELINA

JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTAL PHYSIOLOGY

SPRINGER HEIDELBERG

Lugar: HEIDELBERG; Año: 2018 vol. 188 p. 141 - 152

0174-1578

The thermal physiology determines the whole biology of ectotherm organisms, by limiting their acquisition and allocation of resources. Herein we aim to add knowledge on how different species use the thermal resources when they coexist in a habitat, studying the thermal physiology of three sympatric and syntopic liolaemid lizards, Phymaturus querque, Phymaturus zapalensis, and Liolaemus elongatus during the summer season. We measured the body temperatures at capture places, the operative microenvironmental temperatures in the field, and the preferred body temperature in an experimental thermal gradient in the laboratory. We found that the three species are thermoregulators, selecting cooler thermal microenvironments than the ones expected by chance, and even cooler than the temperatures they selected in a laboratory environment. Liolaemus elongatus is a more efficient thermoregulator (E = 0.671) than the two Phymaturus species, P. querque (E = 0.441) and P. zapalensis (E = 0.471), which are moderate thermoregulators and, apparently, specialists in finding specific types of shelters, since they seem to select certain types of rock crevices. Herein we found that during the summer season, although individuals have access to warm microenvironments, they spend time on cool refuges, probably to prevent overheating. This highlights the importance of an adequate spatial distribution of operative temperatures (Te), more than just a mere availability of appropriate temperatures.