Fig. 1

Measurements of paradoxical anaerobism. a Demonstration of induction of paradoxical anaerobism using 1% ethanol (vol/vol). Pupfish (n = 12 antibiotic-treated pupfish and 12 control pupfish) were placed in the metabolic chamber and oxygen consumption was monitored. At the time indicated by the arrow, ethanol was added to a final concentration of 1% (vol/vol). In this example, an antibiotic-treated pupfish immediately entered paradoxical anaerobism and remained in that metabolic state for the duration of the experiment. b Following addition of ethanol, pupfish oxygen consumption was monitored for ~ 1 h. Data are means ± SE of the % of that time which was spent with negligible oxygen consumption. Values are significantly different (Welch’s t-test, p = 0.037)