Figure 4
A pH–bicarbonate diagram comparing the main acid-base variables in the haemolymph of Cancer pagurus exposed to the 4 treatments: SW = seawater S = 33 (grey symbols); DW = dilute seawater S = 25 (black symbols); CCO2 = control pCO2 (closed circles); HCO2 = elevated pCO2 (open circles). Continuous curved lines represent pCO2 isopleths for Cancer pagurus haemolymph in SW. The associated dotted lines represent the shift in pCO2 isopleths in DW, resulting from salinity-related changes in dissociation constants for carbonic acid. The broken line represents the non-bicarbonate buffer line (β = 12 mmol l−1 pH−1) taken from78 adjusted for the protein levels measured in Cancer pagurus haemolymph. Values given as means ± SEM (n = 32 in SW + CCO2; n = 31 in SW + HCO2; n = 29 in DW + CCO2; n = 27 in DW + HCO2).
