Figure 1From: Physiological responses of Daphnia pulex to acid stressHemolymph buffer curves and non-bicarbonate buffer values. (A) Hemolymph buffer curves of animals raised at 20°C at pH 7.8 (open symbols), pH 6.0 (grey-filled symbols), and pH 5.5 (filled symbols). The symbols represent the mean of a three-fold determination. The error in the concentration of chemically bound CO2 arises from the standard error in the calculation of CO2 partial pressure (PCO2) for a given pH (Table 1). The solid lines were calculated using the equations 1–3 and the means of the individual (curve-specific) parameter values given in Table 1. Dotted lines represent the PCO2 isobars. The triangles indicate the in vivo acid-base state of the respective acclimation groups. (B) Non-bicarbonate buffer values (βA) calculated from equation 4.Back to article page