Figure 1

(A) Four main types of stress responses depending on the amplitude and the time course, involved in hardening have been described in Conrath et al. 28 and Hilker et al. 18: (a) an earlier stress response (type I response), (b) a faster stress response (type II response), (c) a stronger stress response (type III response) and (d) a higher sensitivity hardening stress response (type IV response). Continuous lines indicate primed response to stress while dashed lines indicate non-primed response to stress. (B) Effect of water temperature (24, 26 and 28 °C) on the mortality of heat hardened (H) and non-hardened (C) Mytilus galloprovincialis compared to control at 18 °C.