Fig. 5. Oxygen consumption of snails cutaneously respiring in either PW or CE. (A) Total averaged data (means ± 1 s.e.m.) demonstrating oxygen depletion in a closed chamber for snails in either CE (top red trace) or PW (bottom blue trace) measured as percentage O₂ saturation. The two traces are significantly different (repeated measures analysis for time-linked measurements on each snail, N=9, P<0.001). (B) The ratio of CE to PW O₂ consumption for each snail at each time interval, reference line at 0.