Escape temperature of the intertidal zone porcelain crab Petrolisthes cinctipes does not acclimatize to temperature, but is dependent on body condition, reproductive status and injuries

Temperature influences population distribution, body size and metabolism, making it a driving ecological and evolutionary factor. Due to global climate change, sea surface temperatures are expected to increase by 1.8 - 3.5 degrees C and extreme weather is anticipated to be more intense and frequent by the end of the century. These changes will impact many organisms, especially those exposed to steep environmental gradients and living near their environmental tolerance limits, such as organisms living in intertidal zone habitats. Therefore, climate change is expected to have a large effect on intertidal zone species and such effects have already been demonstrated in several locations across the globe. During a one-year study, we examined how seasonal habitat temperature variation and body condition influence the temperature sensitivity of intertidal zone porcelain crabs. The temperatures that elicited avoidance behavior (i.e., escape temperatures) were measured in the field to capture the physiological state of crabs acclimatized to the natural habitat. Seasonal microhabitat temperature did not influence escape temperature, nor did maximum microhabitat temperatures during the 4 days prior to assay, indicating a lack of thermal plasticity for escape temperature. Escape temperatures were positively correlated with body condition and influenced by the presence of injuries. Overall, this research contributes to an understanding of thermal acclimatization of intertidal zone marine invertebrates and how they may behaviorally respond to thermal pressures brought on by climate change.