Shift in the gastrointestinal bacterial community of Theodoxus fluviatilis in response to changing salinity

Differences in salinity are boundaries acting as barriers to dispersal for many animals but also bacterial species. This creates distinctive biota on freshwater vs brackish water environments. To test how saline boundaries influence the diversity and composition of host-associated microbiota we analyzed the microbiome of Theodoxus fluviatilis, an organism able to cross the boundaries between freshwater and brackish water realms. We investigated the response of the bacterial communities in the gastrointestinal tract of T. fluviatilis in situ samples from different salinities combined with in vivo salinity manipulations.