Whole blood-oxygen binding properties of four cold-temperate marine fishes: blood affinity is independent of pH-dependent binding, routine swimming performance and environmental hypoxia.

The relationship between whole blood-oxygen affinity (P_{50}) and pH-dependent binding (i.e., cooperativity and the Bohr [Φ] and Root effects) was examined statistically under standardized conditions (10.0°C) in four unrelated cold-temperate marine fishes that differ widely in their swimming perform...

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Bibliographic Details
Published in:Physiological and Biochemical Zoology
Main Authors: Herbert, NA, Skov, PV, Wells, RMG, Steffensen, JF
Format: Article in Journal/Newspaper
Language:unknown
Published: The University of Chicago 2006
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Online Access:http://hdl.handle.net/2292/16296
https://doi.org/10.1086/506000
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Summary:The relationship between whole blood-oxygen affinity (P_{50}) and pH-dependent binding (i.e., cooperativity and the Bohr [Φ] and Root effects) was examined statistically under standardized conditions (10.0°C) in four unrelated cold-temperate marine fishes that differ widely in their swimming performance and their expected responses to hypoxia: cod (Gadus morhua), herring (Clupea harengus), mackerel (Scomber scombrus), and plaice (Pleuronectes platessa). An unexpected difference in blood-oxygen affinity was found (herring> plaice> mackerel> cod)), and this was independent of both swimming performance and the predicted low O_{2} response of each species. The ecotype of the four marine species was also unrelated to pH-dependent binding because no difference in the Bohr effect was apparent (Φ varied insignificantly from -0.90 to -1.06), and differences in the magnitude of the cooperative binding reaction were associated only with the presence of the Root effect. Although several reviews propose a generalized link between blood-oxygen affinity and pH-dependent binding, our results advise against overestimating the adaptive functional properties of hemoglobin across unrelated species.