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 [ Phi ] and Root effects) was examined statistically under standardized conditions (10.0 degrees Celsius) 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 ( Phi 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.
Herbert
Neill A
NA
Marine Biological Laboratory, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark. n.herbert@bio.gla.ac.uk
Skov
Peter V
PV
Wells
Rufus M G
RM
Steffensen
John F
JF
D000818:Animals; D003080:Cold Temperature; D017753:Ecosystem; D005399:Fishes / Q000097:blood* / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas; D010100:Oxygen / Q000097:blood* / Q000378:metabolism*; D013550:Swimming / Q000502:physiology*
D010100:Oxygen