Fig. 3. Chemical diversity of coral reef holobiont sample types and genera show the degree of host specificity at both phylum and generic levels.

Venn diagrams illustrate chemical richness among hosts: a Counts of common and unique ion features among coral (n = 42), CCA (n = 37), and macroalgae (n = 24). b Comparison between Porites (n = 16), Monitipora (n = 13), and Pocillopora (n = 13) coral genera and c Comparison between Halimeda (n = 7), Galaxaura (n = 4), and Jania (n = 4) macroalgae genera (“other” refers to the less sampled algae genera (n = 9)). Ordinations (nonmetric multidimensional scaling of Bray-Curtis dissimilarity matrices from 8054 ion feature relative abundances) illustrate compositional differences among d metabolites from each sample type (PERMANOVA R² = 0.16; p < 0.001) and metabolites from genera of coral (e) and macroalgae (f).