Pupfish Microbiome and Paradoxical Anaerobism

The Devils Hole Pupfish (Cyprinodon diabolis) frequently enters paradoxical anaerobism in response to endogenously produced or exogenously supplied ethanol in a dose-dependent manner. We speculate that members of gut microbiota may consume ethanol through secondary fermentation and therefore regulate transitions from paradoxical anaerobism to aerobic respiration, thereby playing a critical role in regulating the metabolic status of these fish. This study reports the first characterization of gut microbial communities of critically endangered pupfish, suggests the microbiome may play a critical role in regulating metabolic strategies employed by the fish to survive in extremes of temperature and oxygen concentration.