Fig. 1: Bacterial composition in samples taken from algae, PCM, and different developmental M. lignano stages.

In A, relative bacterial abundances of algae, pre-conditioned medium (PCM), eggs, immature and mature worms (IMWs and MWs). Colored rectangles are used to distinguish different families of microorganisms. In B–E, Alpha-diversity metrics, including the Dominance measure, Faith’s phylogenetic diversity, Pielou’s evenness, and Shannon’s index show the diversity of bacterial samples from different sources. In F, Bray-Curtis distances of all samples in comparison with MWs are shown. G The non-metric multidimensional scaling (NMDS) plot based on the Bray-Curtis distances analyses (stress value = 0.069). The different microbial colonizer taxa are listed with color-coded assignments. Each group employed 5 mature or 10 immature animals with five biological replicates. Asterisks denote significant differences between samples (one-way ANOVA with Turkey Post-hoc test), *p < 0.05, **p < 0.01,***p < 0.001.