More Than Breathing Air: Evolutionary Drivers And Physiological Implications Of An Amphibious Lifestyle In Fishes

Amphibious and aquatic air-breathing fishes both exchange respiratory gasses with the atmosphere, but these fishes differ in physiology, ecology, and possibly evolutionary origins. We introduce a scoring system to characterize inter-specific variation in amphibiousness and use this system to highlight important unanswered questions about the evolutionary physiology of amphibious fishes.