Fig. 2. A typical normoxic—anoxic—normoxic respirometry recording for Cormocephalus morsitans at 20 °C in dry air. The markers indicate when the airflow was changed from normoxic (21 % O₂, balance N₂) to anoxic (pure N₂) and back to normoxic again. The large bursts of CO₂ emission indicate the end of the closed phase, when the centipede initiates a flutter phase (functionally equivalent to those observed in insects) to maintain O₂ partial pressure sufficient for cellular respiration.