Fig. 1

Metabolome (polar extracts) characterization of marine annelids Platynereis spp. reciprocally transplanted between high or low pCO₂ conditions (four treatments, CC = collected in low pCO₂ and transplanted to low pCO₂, CA = collected in low pCO₂ and transplanted to high pCO₂, AA = collected in high pCO₂ and transplanted to high pCO₂, and AC = collected in high pCO₂ and transplanted to low pCO₂). (a) Principal Components Analysis 2D score plot of the four groups with 95% confidence intervals, (b) Sample cluster analysis using Euclidean distance and Ward’s clustering algorithm, (c) Principal Components Analysis 2D score plot of the metabolome of annelids according to regime of origin (control, including group CC and CA; and acidified, including group AA and AC) with 95% confidence intervals, (d) Principal Components Analysis 2D score plot of the metabolome of annelids according to transplant type, namely between the same environment (SE, which includes CC and AA annelids), or different environment (DE, which includes CA and AC annelids) with 95% confidence intervals. (e) Volcano plot representing differentially abundant metabolites (n = 129, coloured as red dots) according to worm regime of origin (control vs. acidified), based on t-tests with 250 randomizations, FDR 0.05 and s 0.1. (f) Volcano plot highlighting that there are no differences in the metabolome of annelids according to transplant type, based on t-tests with 250 randomizations, FDR 0.05 and s 0.1.