Taxonomic affiliation of the clones representing the bacterial OTUs, sorted per Bryopsis sample.

1Chloroplast 16S rRNA gene sequences were derived from clones MX19.1, MX90.9, MX164.1, MX263.48 and MX344.10 with an OTU library percentage of, respectively, 79.7, 93.5, 20.7, 68 and 97.8 percent per sample.2All bacterial OTUs containing clones derived from different Bryopsis strains had minimal intra-OTU sequence similarities of ≥97% ranging from exactly 97% in OTU-4, over 99.3% and 99.7% in, respectively, OTU-2 and OTU-1, to no less than 99.9% pairwise similarity in OTU-3.3Especially noteworthy is the abundance of OTU-5 in the MX164 sample's clone library. While the bacterial OTUs 1, 3, 4 and 6 have a low occurrence of 0.8–7.1% and OTU-2 a considerable presence of 14.2–22.6% in their respective clone libraries, OTU-5 amounts to a substantial percentage (63.6%) of the MX164 sample's clones. In addition, only Bryopsis sample MX263 comprised chimeric Flavobacteriaceae-Bryopsis chloroplast 16S rRNA gene sequences which made up 4% of the sample's clone library.