INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Fever in the cold: the case of the southernmost lizards of the world, Liolaemus sarmientoi, from Patagonia, Argentina
Autor/es:
BORETTO, J.; IBARGÜENGOYTÍA N. R; FERNANDEZ, JIMENA BEATRIZ; DURAN, F; IBÁÑEZ-MOLINA, M
Lugar:
Hangzhou
Reunión:
Congreso; 8th World Congress of Herpetology; 2016
Resumen:
Poleward distribution shifts of species due global warming represent a threat of new parasites, viral infections and bacteria for the resident populations. Health condition could affect running performance, stamina, thermoregulation behavior and field body temperature (T b ). Lizards develop hypothermia or hyperthermia through thermoregulation to enhance their immune system and counteract the effects of parasites and infection. The aim of this study was to characterize the immunological state and its? relationship with the thermal biology, locomotor performance, stamina and body condition of one of the southernmost lizards of the world Liolaemus sarmientoi, from the southern Patagonian steppe of Argentina, South America. We studied 22 males captured in 2011 at 50°S, 72°W and 51ºS, 70ºW (133 m asl). Blood smears stained with May-Grünwald Giemsa were used to determine the proportion of white cells and to compare with T b , body condition index, stamina, running performance and preferred temperature (T pref ). Juveniles and adults show similar leukocyte profile (25% heterophils, 70% lymphocytes, 3% basophils, 1% eosinophils and < 1% monocytes). In adults, the mean and minimum T pref increase with a higher proportion of basophils and eosinophils, respectively. But juveniles seem to not be able to modify their T pref according to leukocyte profile. The body condition related negatively with the increment of basophils in adults but, sprint speed, long run performance or the stamina seem to not be related with the lizards healthiness. Notwithstanding, the function of white cells still not certain in reptiles, the increment in basophils and eosinophils can be associated with the parasites, allergic reactions, and with the modulation of inflammation processes. The understanding of the mechanisms of the lizard immune system and the reaction norms to infections opens a new perspective about thermal physiology and vulnerability of populations to climate change.