Metabolomic profiling
The metabolome of Daphnia samples were analysed at the Natural Environment Research Council (NERC) Biomolecular Analysis Facility at the University of Birmingham (UK). The metabolome of Daphniasamples were analysed using nano-electrospray ionization - direct infusion mass spectrometry (nESI-DIMS) as described by Southam et al. (2017). The detailed methods for the nESI-DIMS was in the supporting information. Briefly, polar metabolites were first extracted from D. magna samples using a biphasic method. Then, all samples were analysed in both positive and negative ionisation modes using an Orbitrap Elite mass spectrometer (Thermo Fisher Scientific, Bremen, Germany) with a direct infusion, chip-based nano-electrospray ionization source (Triversa, Advion Biosciences, Ithaca, NY, USA). The data processing was done using the Galaxy online platform using the selected ion monitoring (SIM) stitching algorithm (Southam et al. 2017) (see supporting information for details). The processed data matrices were used for statistical analyses.