Extended Data Fig. 5: Influence of keystone environmental bacteria in animal-associated microbiomes isolated from macroalgae and water.

SPIEC-EASI co-occurrence network of key environmental ASVs found in Quadra Island a, macroalgae (n = 253 ASVs) and b, water column (n = 228 ASVs) samples. Each node represents a single ASV. Lines connecting two nodes (edges) indicate an association between the two ASVs. Node size is scaled to eigen-centrality, which considers the number of connecting nodes as well as their subsequent connections. c,d, prevalence and abundance (both as %) of the same environmental ASVs (respective of each habitat) in animals from the same habitat and location. Individual ASVs (on the x axis) are ordered according to their eigen-centrality in the environmental network, and may be represented by multiple datapoints in the abundance plot (on the right) to reflect their varying abundance in multiple host phyla. Grey arrowheads in prevalence plots indicate environmental ASVs that are absent in host-associated microbiomes. Point colour indicates host phyla. As is the case in sediments from the same location (see text), keystone environmental bacteria are not particularly abundant nor prevalent in animal-associated microbiomes.