Divergent thermal sensitivities among different life stages of the pulmonate limpet Siphonaria japonica

Abstract

The different life-history stages of organisms may have divergent thermal limits and thus respond differently to global warming. For comprehensive understanding of the ecological impacts of global warming, it is crucial to determine thermal limits among different life stages and to understand how close an organism lives to its thermal limits at different life stages. Here, we measured the effect of temperature on hatching and the lethal temperature (LT50, lethal temperature of 50%) of larvae to explore effects of high temperature on the encapsulated and planktonic stages of the pulmonate limpet Siphonaria japonica. We measured cardiac performance to determine adult limpets’ thermal limit. At the encapsulated stage, heat shock at 34.5 °C affected larval hatching significantly. Pelagic larvae showed a high LT50 (45.03 °C), indicating a high thermal tolerance for the pelagic larval stage. For the adults, the Arrhenius break temperature and flatline temperature were 38.49 ± 1.27 and 44.27 ± 1.08 °C, respectively. The integrated study of environmental temperatures and thermal sensitivities at different life stages of S. japonica indicates that the egg ribbon and adult stages are potentially most sensitive to the future temperature increases on subtropical shores.