“…[22][23][24][25][26][27][28] For example, 1D 31 P NMR was extensively used to investigate the physiology of Balanus nubilis, Clarias batrachus embryo, and larvae of plaice under in vivo conditions, where various important energy molecules, such as ATP or ADP, were identified based on their unique 31 P chemical shifts signatures. [21,23,[29][30][31][32] Recently, in vivo 1 H NMR spectroscopy was successfully applied to whole aquatic organisms, namely, D. magna and Hyalella azteca, illustrating the applicability of this approach for in vivo applications. [5,[33][34][35] Lastly, with an improvement in NMR sensitivity and isotopic enrichment, 2D 1 H- 13 C heteronuclear NMR spectroscopy has been performed on living multicellular organisms including Caenorhabditis elegans, [36] D. magna, [2,6,37] and H. azteca, [5,19] where the additional spectral dispersion afforded by 1 H-13 C 2D NMR spectra allows more metabolites to be identified in vivo, compared with a 1D 1 H NMR spectrum, and stress processes to be monitored with unprecedented molecular resolution.…”