Evolutionary and cardio‐respiratory physiology of air‐breathing and amphibious fishes

Air‐breathing and amphibious fishes are essential study organisms to shed insight into the required physiological shifts that supported the full transition from aquatic water‐breathing fishes to terrestrial air‐breathing tetrapods. While the origin of air‐breathing in the evolutionary history of the tetrapods has received considerable focus, much less is known about the evolutionary physiology of air‐breathing among fishes. This review summarizes recent advances within the field with specific emphasis on the cardiorespiratory regulation associated with air‐breathing and terrestrial excursions, and how respiratory physiology of these living transitional forms are affected by development and personality. Finally, we provide a detailed and re‐evaluated model of the evolution of air‐breathing among fishes that serves as a framework for addressing new questions on the cardiorespiratory changes associated with it. This review highlights the importance of combining detailed studies on piscine air‐breathing model species with comparative multi‐species studies, to add an additional dimension to our understanding of the evolutionary physiology of air‐breathing in vertebrates.