The influence of temperature on the hemolymph CO2 solubility coefficient (αco2 , µM/L/torr) was investigated in the marine bivalves, akoya pearl oyster Pinctada fucata martensii, Pacific oyster Crassostrea gigas and noble scallop Mimachlamys nobilis. Hemolymph samples were equilibrated with standard CO2 gas mixtures to obtain expressions for αco2 as a function of temperature. Relationships between hemolymph αco2 and temperature (T) were expressed as follows: αco2 = 76.88145 − 2.62637 ･ T + 0.036203 · T2 (for P. fucata martensii), αco2 = 94.2109 – 3.6252 · T + 0.0554 · T2 (for C. gigas), αco2 = 70.4591 – 1.5253 · T + 0.0103 · T2 (for M. nobilis). In the distribution of hemolymph αco2 values, there was no statistical significance across an interspecies comparison of αco2 . From this result, the regression was fitted using all values of αco2 and temperature across the species, and the relationship was expressed as follows: αco2 = 182.3717 – 24.3932 · T + 1.6396 · T2 – 0.0492 · T3 + 0.000536 · T4. This polynomial is versatile equation and would yield the hemolymph αco2 at arbitrary temperature, even with different species.
Handa et al. (Thu,) studied this question.