van Aardt W J, Frey B J
Comp Biochem Physiol A Comp Physiol. 1986;83(2):397-400. doi: 10.1016/0300-9629(86)90595-5.
For Labeo capensis (Smith) the increase in blood organic phosphates (ATP, GTP) in winter fish exceeds the increase in summer fish. Blood chlorides, blood osmotic pressure, hematocrit and hemoglobin concentration decrease significantly in winter fish when compared to summer fish. Four effectors, viz. temperature, organic phosphates, H+ and Cl-, could lower the oxygen affinity of whole blood, especially in summer fish.