Leung, J.Connell, S.Russell, B.2018-03-152018-03-152017Scientific Reports, 2017; 7(1):17688-1-17688-82045-23222045-2322http://hdl.handle.net/2440/111063Extreme climatic events, such as heatwaves, are predicted to be more prevalent in future due to global climate change. The devastating impacts of heatwaves on the survival of marine organisms may be further intensified by ocean acidification. Here, we tested the hypothesis that prolonged exposure to heatwave temperatures (24 °C, +3 °C summer seawater temperature) would diminish energy budget, body condition and ultimately survival of a subtidal gastropod (Thalotia conica) by pushing close to its critical thermal maximum (CTmax). We also tested whether ocean acidification (pCO2: 1000 ppm) affects energy budget, CTmax and hence survival of this gastropod. Following the 8-week experimental period, mortality was markedly higher at 24 °C irrespective of pCO2 level, probably attributed to energy deficit (negative scope for growth) and concomitant depletion of energy reserves (reduced organ weight to flesh weight ratio). CTmax of T. conica appeared at 27 °C and was unaffected by ocean acidification. Our findings imply that prolonged exposure to heatwaves can compromise the survival of marine organisms below CTmax via disruption in energy homeostasis, which possibly explains their mass mortality in the past heatwave events. Therefore, heatwaves would have more profound effects than ocean acidification on future marine ecosystems.en© The Author(s) 2017. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Marine biology; physiologyJournal article003007957010.1038/s41598-017-16341-10004182508000732-s2.0-85038440084390398Leung, J. [0000-0001-5846-3401]Connell, S. [0000-0002-5350-6852]Russell, B. [0000-0003-1282-9978]