The role of nest surface temperatures and the brain in influencing ant metabolic rates |
| |
| Institution: | 1. Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia;2. Department of Conservation Ecology and Entomology, Centre for Invasion Biology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland, 7602 Stellenbosch, South Africa;1. Department of Oral Health Sciences, University of Washington, Seattle, WA, USA;2. Division of Biological Sciences, School of STEM, University of Washington, Bothell, WA, USA;1. Department of Biology, University of Florence, via Madonna del Piano 6, Sesto Fiorentino, Italy;2. South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in ?eské Budějovice, Záti?í 728/II, 389 25, Vodňany, Czech Republic;3. Department of Earth Sciences, University of Florence, via G. La Pira 4, Firenze, Italy;4. Institute of Geosciences and Earth Resources (IGG), National Research Council of Italy (CNR), via G. La Pira 4, Firenze, Italy;1. IMT School for Advanced Studies Lucca, Lucca, Italy;2. National Research Council, Institute for Complex Systems Studies, Rome, Italy;3. University of Toronto, Canada;4. Enel Foundation, Rome, Italy;1. Department of Ecology and Evolution, Biophore, UNIL-Sorge, University of Lausanne, 1015 Lausanne, Switzerland;2. School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK;1. Laboratoire Mer-Molécules-Santé (MMS-BiOSSE), Le Mans Université, 72000, Le Mans, France;2. Institute of Ecology and Environmental Sciences (iEES-Paris), Sorbonne Université, 75005, Paris, France;3. Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa, Japan;4. Radcliffe Institute for Advanced Study, Harvard University, Cambridge, MA, 02445, USA |
| |
| Abstract: | Thermal limits of insects can be influenced by recent thermal history: here we used thermolimit respirometry to determine metabolic rate responses and thermal limits of the dominant meat ant, Iridomyrmex purpureus. Firstly, we tested the hypothesis that nest surface temperatures have a pervasive influence on thermal limits. Metabolic rates and activity of freshly field collected individuals were measured continuously while ramping temperatures from 44 °C to 62 °C at 0.25 °C/minute. At all the stages of thermolimit respirometry, metabolic rates were independent of nest surface temperatures, and CTmax did not differ between ants collected from nest with different surface temperatures. Secondly, we tested the effect of brain control on upper thermal limits of meat ants via ant decapitation experiments (‘headedness’). Decapitated ants exhibited similar upper critical temperature (CTmax) results to living ants (Decapitated 50.3±1.2 °C: Living 50.1±1.8 °C). Throughout the temperature ramping process, ‘headedness’ had a significant effect on metabolic rate in total (Decapitated V?CO2 140±30 µl CO2 mg?1 min?1: Living V?CO2 250±50 CO2 mg?1 min?1), as well as at temperatures below and above CTmax. At high temperatures (>44 °C) pre- CTmax the relationships between I. purpureus CTmax values and mass specific metabolic rates for living ants exhibited a negative slope whilst decapitated ants exhibited a positive slope. The decapitated ants also had a significantly higher Q10:25–35 °C when compared to living ants (1.91±0.43 vs. 1.29±0.35). Our findings suggest that physiological responses of ants may be able to cope with increasing surface temperatures, as shown by metabolic rates across the thermolimit continuum, making them physiologically resilient to a rapidly changing climate. We also demonstrate that the brain plays a role in respiration, but critical thermal limits are independent of respiration levels. |
| |
| Keywords: | Meat ants Formicidae Neural control Thermal stress Thermolimit respirometry |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
