The influence of temperature on the hemolymph CO2 solubility coefficient (αco2) and the apparent dissociation constant of carbonic acid (pKapp) in Mytilus coruscus was investigated. Mytilus coruscus hemolymph was equilibrated with standard CO2 gas mixtures to obtain expressions for αco2 and pKapp as a function of temperature.The relationship between αco2 and temperature (T) is expressed as follows: αco2 = 138.247 – 11.253 • T + 0.554 •T2 − 0.0140 • T3 + 0.000138 • T4. The following relationship between pKapp and temperature was found: pKapp =6.6407 – 0.01589 • T . The parameter units are ℃ for T and µM/L/torr for αco2. These equations enable estimation of hemolymph αco2 and pKapp at arbitrary temperatures and simple calculation of Pco2 and HCO3–.
Handa et al. (Fri,) studied this question.