Incorporating environmental variability into physiological experiments: rationale and resources

Our understanding of how environmental variability shapes animal physiology and behaviour is rapidly evolving. This is largely facilitated by a new wave of physiology research that has embraced environmental variability by simulating real-world conditions in experimental designs. While the move away from classical static holding conditions offers promising insights into environmental physiology, it can also be logistically challenging, time-intensive and expensive. Here, we review when and where variability arises in aquatic environments and highlight exemplary studies that demonstrate how embracing variability can help us better understand organismal performance. We also discuss challenges associated with various types of manipulations and summarize technological advances, considerations and tips that we hope will make it less daunting for researchers to investigate the effects of environmental variability. This article is part of the theme issue 'Embracing variability in comparative physiology: why it matters and what to do with it'.