Don't throw the fish out with the respirometry water

Dr Wood's Commentary ([Wood, 2018][1]) provides six reasons to question the usefulness of P crit and proposes alternative Ṁ O2 versus P O2 analyses as its replacement. While we agree with some of Dr Wood's arguments, we feel that none of them warrant abandoning P crit, especially in favour of

[1]  J. Alexander,et al.  Assessment of oxygen consumption in response to progressive hypoxia , 2018, PloS one.

[2]  K. A. S. Mislan,et al.  Ocean deoxygenation and zooplankton: Very small oxygen differences matter , 2018, Science Advances.

[3]  C. Wood,et al.  The fallacy of the Pcrit – are there more useful alternatives? , 2018, Journal of Experimental Biology.

[4]  J. Richards,et al.  Evolution of Cytochrome c Oxidase in Hypoxia Tolerant Sculpins (Cottidae, Actinopterygii) , 2017, Molecular biology and evolution.

[5]  J. Richards,et al.  Calorespirometry reveals that goldfish prioritize aerobic metabolism over metabolic rate depression in all but near-anoxic environments , 2017, Journal of Experimental Biology.

[6]  G. Claireaux,et al.  Responses by fishes to environmental hypoxia: integration through Fry's concept of aerobic metabolic scope. , 2016, Journal of fish biology.

[7]  J. Richards,et al.  Mechanisms and evolution of hypoxia tolerance in fish , 2009, Proceedings of the Royal Society B: Biological Sciences.

[8]  J. Richards,et al.  The Osmorespiratory Compromise in Sculpins: Impaired Gas Exchange Is Associated with Freshwater Tolerance , 2008, Physiological and Biochemical Zoology.

[9]  G. Nilsson,et al.  Hypoxia induces adaptive and reversible gross morphological changes in crucian carp gills , 2003, Journal of Experimental Biology.

[10]  J. Childress,et al.  Life at stable low oxygen levels: adaptations of animals to oceanic oxygen minimum layers. , 1998, The Journal of experimental biology.

[11]  G. R. Ultsch,et al.  Physiological Regulation and Conformation: A BASIC Program for the Determination of Critical Points , 1989, Physiological Zoology.