Excess post-hypoxic oxygen consumption in Atlantic cod Gadus morhua

Atlantic cod Gadus morhua experienced oxygen deficit (D-O2) when exposed to oxygen levels below their critical level (c. 73% of pcrit) and subsequent excess post-hypoxic oxygen consumption (C-EPHO) upon return to normoxic conditions, indicative of an oxygen debt. The mean +/- s. e. C-EPHO:D-O2 was 6.9 +/- 1.5, suggesting that resorting to anaerobic energy production in severe hypoxia is energetically expensive. (C) 2013 The Fisheries Society of the British Isles