Latitudinal pattern of the thermal sensitivity of running speed in the endemic lizard Liolaemus multimaculatus

STELLATELLI, OSCAR ANÍBAL; VEGA, LAURA E.; BLOCK, CAROLINA; ROCCA, CAMILA; BELLAGAMBA, PATRICIO; DAJIL, JUAN ESTEBAN; CRUZ, FÉLIX BENJAMÍN

Integrative Zoology

Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Lugar: Sydney; Año: 2022 vol. 17 p. 619 - 637

1749-4877

Physiological performance in lizards may be affected by climate across latitudinal or altitudinal gradients. In thecoastal dune barriers in central-eastern Argentina, the annual maximum environmental temperature decreases upto 2°C from low to high latitudes, while the mean relative humidity of the air decreases from 50% to 25%. Liolaemusmultimaculatus, a lizard in the family Liolaemidae, is restricted to these coastal dunes. We investigated thelocomotor performance of the species at 6 different sites distributed throughout its range in these dune barriers.We inquired whether locomotor performance metrics were sensitive to the thermal regime attributable to latitude.The thermal performance breadth increased from 7% to 82% with latitude, due to a decrease in its critical thermalminimum of up to 5°C at higher latitudes. Lizards from high latitude sites showed a thermal optimum, that is, thebody temperature at which maximum speed is achieved, up to 4°C lower than that of lizards from the low latitude.At relatively low temperatures, the maximum running speed of high-latitude individuals was faster than that oflow-latitude ones. Thermal parameters of locomotor performance were labile, decreasing as a function of latitude.These results show populations of L. multimaculatus adjust thermal physiology to cope with local climatic variations.This suggests that thermal sensitivity responds to the magnitude of latitudinal fluctuations in environmentaltemperature.