| Full text | |
| Author(s): |
Total Authors: 3
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| Affiliation: | [1] Univ Sao Paulo, Inst Biosci, Dept Physiol, Lab Behav & Evolutionary Physiol, BR-05508090 Sao Paulo - Brazil
Total Affiliations: 1
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| Document type: | Journal article |
| Source: | Journal of Thermal Biology; v. 93, OCT 2020. |
| Web of Science Citations: | 1 |
| Abstract | |
Predicting the effects of high environmental temperatures and drought on populations requires understanding how these conditions will influence the thermoregulatory behavior and thermal tolerance of organisms. Ectotherms show proportional (fine-tuned) and all-or-none (abrupt) responses to avoid overheating. Scattered evidence suggests that dehydration alters these behavioral responses and thermal tolerance, but these effects have not been evaluated in an integrative manner. We examined the effects of hydration level on the behavioral thermoregulation and behavioral and physiological thermal limits of the ``bullfrog{''} (Rana catesbeiana), a well-studied and important invasive species. To examine the effects of dehydration on proportional responses, we compared the Preferred Body Temperatures (PBT) of frogs with restricted and unrestricted access to water. To assess the effect of dehydration on all-or-none responses, we measured and compared the Voluntary Thermal Maximum (VTMax) at different hydration levels (100%, 90%, 80% of body weight at complete hydration). Finally, to understand the effect of dehydration on physiological thermal tolerance, we measured the Critical Thermal Maximum (CTMax) of frogs at matched hydration levels. PBT, VTMax, and CTMax all decreased in response to higher dehydration levels. However, bullfrogs changed their PBT more than their VTMax or CTMax in response to dehydration. Moreover, some severely dehydrated individuals did not exhibit a VTMax response. We discuss the implications of our results in the context of plasticity of thermoregulatory responses and thermal limits, and its potential application to mechanistic modeling. (AU) | |
| FAPESP's process: | 14/16320-7 - Impacts of climate/environmental change on the fauna: an integrative approach |
| Grantee: | Carlos Arturo Navas Iannini |
| Support Opportunities: | Research Program on Global Climate Change - Thematic Grants |
| FAPESP's process: | 17/14382-3 - Interaction of behavior and physiology of anurans in response to thermal and water stress: an approach to understand the vulnerability of anurans to climate change |
| Grantee: | Estefany Caroline Guevara Molina |
| Support Opportunities: | Scholarships in Brazil - Master |