摘要：SummaryBacteroidetes bacteria are frequently found in association with sponges, but their roles in host development are poorly understood. In this study, thirteen bacterial species (12 genera) isolated from the spongeTedaniasp. revealed a common ability to significantly promote sponge larval settlement at rates 30.00–53.33% higher than controls (p < 0.05). Three effective strategies were adapted: (i) two strains formed biofilms enhancing the settlement rate to 56.67–63.33% within three days. (ii) Five strains secreted hydrosoluble molecules improving larval settlement, reaching 59.17%. (iii) Six species produced extracellular vesicles (EVs) that significantly improved settlement by up to 86.67% (p < 0.05). The EV fluorescence demonstrated that they migrated inside the sponge larvae from the planktonic to metamorphosis stage. Generally, marine sponges specifically enrich Bacteroidetes bacteria because of the important player in host development, establishing the basis for reciprocal adaptive co-evolution between the microbial community and animals, even including higher organisms.Graphical abstractDisplay OmittedHighlights•Bacteroidetes strains positively affected spongeTedaniasp. settlement•Bacteroidetes strains forming three strategies interacted with sponge•Bacteroidetes extracellular vesicles (EVs) can promote sponge larval settlement•Bacteroidetes EVs were internalized by sponge larva and migrated inside itMarine organism; Ecology; Microbiology;
