Fig. 5

Gut microbiota structure and diversity of D. vulgaris investigated in BO (Small-scale dataset). A Principal Component Analysis ordination plot representing the gut bacterial communities of fish individuals from the seven sampling locations. The distances were obtained by calculating the Aitchinson’s distances on the CLR transformed abundances of the ASV (not agglomerated at higher taxonomical levels). B Shannon diversity index (at the ASV level) of the gut bacterial communities of individuals from the seven sampling locations. The P-value of significant pairwise differences between sampling locations (according to Dunn’s post hoc test) is reported over the boxplots (* P value < 0.05). C Linear regression calculated between the Shannon diversity index (at ASV level) and the proportion of the Posidonia oceanica meadows inferred in the home range of the individuals collected at each sampling location (Adjusted R² = 0.22, P value = 0.0002). The shaded area represents a point-wise 95% confidence level