Table 3.

Examples of application of metabolomics to environmental and biological studies of marine organisms

Organisms	Analytical method	Pattern recognition		Finding	References
		Unsupervised	Supervised
Coral Pocillopora damicornis	UHPLC-ESI-Q-TOF–MS and GC-EI-TOF–MS	No	OPLS-DA	Exposure to different conditions of temperature and pCO2 shift metabolic pathways including carbohydrate metabolism, cell structural maintenance, defense mechanisms among others	Sogin et al. (2016)
Coral Sarcophyton spp., Lobophytum pauciflorum, and Sinularia polydactyla	UHPLC-ESI-LCQ-MS and 1H NMR	PCA	OPLS	Coral growth in the wild exhibit higher levels of cembranoids, the most common group of diterpenes reported for soft corals, while corals growing in an aquarium have a higher content of oxylipins	Farag et al. (2016)
Alga Fucus vesiculosus and Fucus serratus	GC-EI-TOF–MS	MDSa	dbRDAb	For two algae belonging to Fucus genus changes in the surface chemistry during different season was observed. Compounds such as, saccharides, hydroxy acids and fatty acids were found to be up regulated during the summer and environmental conditions such light were found to be related with these metabolic changes	Rickert et al. (2016)
Bacteria Persicivirga (Nonlabens) mediterranea TC4 and TC7 Pseudoalteromonas lipolytica TC8 and Shewanella sp. TC11	UHPLC − ESI-Q-TOF–MS	PCA and molecular networking	PLS-DA	Different culture conditions are reflected in the metabolome of the four bacteria studied. Compounds of the family of hydroxylated ornithine lipids, diamine lipids and glycine lipids are putative biomarkers	Favre et al. (2017)
Alga Ulva mutabilis	GC-EI-TOF–MS and UHPLC-ESI-TOF–MS	PCoAc	CAPd	The exo-metabolome and development of Ulva mutabilis is changed by the presences of symbionts	Alsufyani et al. (2017)
Clams Ruditapes philippinarum	1H NMR	No	PLS-DA	The analysis of R. philippinarum gills after been exposed to hypoxia showed changes in the concentration of some amino acids and energy related metabolites	Zhang et al. (2017c)
Sea snail Haliotis diversicolor	1H NMR	PCA	OPLS-DA	The exposure of H. diversicolor to organotin contaminant cause changes in the energy metabolism, osmotic balance oxidative stress. Moreover, the metabolic response is different depending on the sex and the tissue analyzed	Lu et al. (2017)
Mussels Mytilus galloprovincialis	1H NMR	PCA	No	The exposure of M. galloprovincialis to drospirenone has no effect in their sexual development but disrupt energy, amino acids, and glycerophospholipid metabolism	Cappello et al. (2017)
Macroalga Asparagopsis taxiformis Coral Astroides calycularis	UHPLC–ESI-QTOF-MS	PCA	No	The interaction between a coral and an invasive alga revealed no changes in the metabolome of the coral while the metabolome of the alga was changed when in contact with the coral	Greff et al. (2017)
Fish Salvelinus alpinus	1H NMR	PCA	PLS-DA	The metabolic changes caused by a test diet were reflected in the metabolome of the plasma, liver and muscle. Based on this, improvements in the diet were proposed	Cheng et al. (2017)
Sponge Haliclona mucosa and Haliclona fulva	UHPLC-ESI-Q-TOF	PCA	No	Differences in the metabolome between the two species were observed. Additionally, a decrease in the diversity of the metabolome during the period between April and May was observed and variation due to the location was detected over a 200 km ratio in the Mediterranean Sea	Reverter et al. (2018)
Fish Thunnus thynnus	1H NMR	PCA	No	Study of the liver tissue of bluefin tuna show differences in the metabolic changes according to the gender, caused by the accumulation of environmental contaminant. Energy-related metabolites, amino acids and lipids were identified as the most affected metabolites	Cappello et al. (2018)
Dinoflagellate Karenia brevis Diatom Asterionellopsis glacialis	1H NMR	PCA	PLS and OPLS-DA	It was found that the allelopathic effect of K. brevis was variable and, in some conditions, it could also be no-allelopathic or even stimulate the growth of A. glacialis. Signal related with aromatic and polyunsaturated alkenes were increased in the allelopathic samples but also in the one with no allelopathy or stimulatory activity, this suggest specific compounds and not a family of compounds are responsible for this effect	Poulin et al. (2018b)

^aMulti-dimensional scaling

^bdistance-based redundancy analysis

^cPrincipal coordinate analysis

^dCanonical analysis of principle coordinates