Additional file 1: Table S1. of Wild eel microbiome reveals that skin mucus of fish could be a natural niche for aquatic mucosal pathogen evolution Carda-DiéguezMiguel GhaiRohit Rodríguez-ValeraFrancisco AmaroCarmen 2017 Metagenomes used to detect MGE. Table S2. General data for each metagenome and alpha diversity. Table S3. Contigs with MGE detected using the methodology described in Fig. 1. Figure S1. Sampling points, location and description. Figure S2. From nature to the laboratory: skin mucus sampling from wild eels and DNA extraction. Figure S3. Mobile genetic elements (MGE) detection workflow diagram. Figure S4. %GC content profiles of the eel’s SMS- and W-metagenomes. Figure S5. Wild eel’s versus farmed eel’s SMS metagenomes. Figure S6. V. metoecus M12v BLAST atlas. Figure S7. Schematic representation of VPI-2 in M12v. Figure S8. Main bacterial genera detected in eel’s SMS- and W-metagenomes. Figure S9. rtxA1 gene comparison. Figure S10. Differences in functional capacities between SMS-associated and water microbiomes. Figure S11. Differences in membrane transport functional categories between SMS-associated and water microbiomes. Figure S12. PCA analysis of hexanucleotide usage pattern (HUP) of water metagenomes. Figure S13. PCA analysis of hexanucleotide usage pattern (HUP) of metagenomes associated to different hosts. Figure S14. Hexanucleotide usage pattern (HUP) distribution of the attached microbiome to epidermal mucus of European eels in WE3 8. Figure S15. Contigs with pMGE. Genes of interest are colored differently. Figure S16. MGE in a contig of Pseudomonas. Figure S17. Distribution of an ICE identified in contigWE3 8C14 between Pseudomonas strains. Figure S18. Exchange of long DNA stretches between genera with similar %GC of the genome. (DOCX 4303 kb)