Oxygen concentration affects upper thermal tolerance in a terrestrial vertebrate
| Autor: | Emily N. Taylor, Robert A. Brewster, Kiley A. Rucker, Tanner K. Shea, P. Mason DuBois, Nicolette E. Murphey, Natalie M. Claunch |
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| Rok vydání: | 2016 |
| Předmět: |
030110 physiology
0301 basic medicine Male Hot Temperature Physiology Acclimatization chemistry.chemical_element Biology Body size Biochemistry Oxygen 03 medical and health sciences Animal science Oxygen Consumption Sex Factors biology.animal parasitic diseases Animals Body Size Critical thermal maximum Molecular Biology Lizard Ecology Temperature Vertebrate Lizards body regions Cold Temperature chemistry Limiting oxygen concentration Female sense organs Metabolic demand |
| Zdroj: | Comparative biochemistry and physiology. Part A, Molecularintegrative physiology. 199 |
| ISSN: | 1531-4332 |
| Popis: | We tested the oxygen limitation hypothesis, which states that animals decline in performance and reach the upper limits of their thermal tolerance when the metabolic demand for oxygen at high temperatures exceeds the circulatory system's ability to supply adequate oxygen, in air-breathing lizards exposed to air with different oxygen concentrations. Lizards exposed to hypoxic air (6% O2) gaped, panted, and lost their righting response at significantly lower temperatures than lizards exposed to normoxic (21% O2) or hyperoxic (35% O2) air. A greater proportion of lizards in the hyperoxic treatment were able to withstand body temperatures above 44°C than in the normoxic treatment. We also found that female lizards had a higher panting threshold than male lizards, while sex had no effect on gaping threshold and loss of righting response. Body size affected the temperature at which lizards lost the righting response, with larger lizards losing the response at lower temperatures than smaller lizards when exposed to hypoxic conditions. These data suggest that oxygen limitation plays a mechanistic role in the thermal tolerance of lizards. |
| Databáze: | OpenAIRE |
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