Linking body condition and thermal physiology in limping crickets: Does limb autotomy incur costs concerning behavioral thermal tolerance?

Abstract

Many ectotherms have the ability to voluntarily detach a body part, known as autotomy, usually in response to predator attacks. Autotomy can have an immediate benefit for survival, but it can also involve costs related to the individual's body condition. Even though the effects of autotomy have been studied in many ecophysiological aspects, its short-term costs on the ability to tolerate high environmental temperatures are still unexplored. Herein, we evaluated the effects of autotomy on the behavioral thermal tolerance (VTMax) in the cricket Gryllus assimilis. We hypothesized that, due to the increased energetic costs to maintain homeostasis, autotomized crickets have a lower VTMax than intact ones. Additionally, we investigated differences in VTMax between sexes, as well as the effects of heating rates and body mass on their VTMax. Contrary to our hypothesis, we found no differences between VTMax of autotomized and intact individuals. However, we observed that females have a higher VTMax than males, regardless of their condition (i.e., autotomized and intact). Moreover, we detected significant effects of body mass and heating rate on behavioral thermal tolerances. The results of our study indicate that costs associated with limb autotomy at high environmental temperatures might be intricate and not immediately impactful. Furthermore, important aspects of reproduction and ecology might be responsible for differences in VTMax between males and females. Our results contribute to understanding the ecological and physiological aspects of ectotherms and how they respond to changing climatic conditions.