Omnibus Kruskal-Wallis one way analysis of variance results of mean (n = 2–4) ΔO2, ΔH+ and ΔCa2+ measured during three pCO2 treatment incubations (432, 1141, 2151 µatm) for different factors.

Significant effects at the Bonferroni corrected 0.83% levels are indicated in bold.


Δ denotes the difference in O2, H+ and Ca2+ respectively between the surface of shell and the bulk seawater determined by microsensor profiling (n = 2–4), averaged over each individual.


levels: photosymbiotic, heterotrophic.


levels: diatoms (Amphistegina radiata, Heterostegina depressa), dinoflagellates (Marginopora vertebralis), red algae (Peneroplis sp.), no symbionts (Quinqueloculina sp., Miliola sp.).


treatment groups represent each combination of species, pCO2, and light phase, according to box-plots represented in Figure 5, 6 and Figure S4.