The study by Roeseler et al. investigates the gut microbial communities of zebrafish, both those recently caught from their natural habitat and those reared in laboratory facilities. The researchers used 16S rRNA gene sequencing to compare the gut microbiota of these two groups of zebrafish. They found that the gut microbiota of domesticated zebrafish varied across different lab facilities, reflecting historical connections between these facilities. However, the gut microbiota of recently caught zebrafish was strikingly similar to that of domesticated zebrafish, suggesting a shared core gut microbiota. The study also identified specific bacterial taxa, particularly members of the γ-Proteobacteria and Fusobacteria classes, that were consistently present in the gut microbiota of zebrafish and other teleost fish species. Phylogenetic analysis revealed a diverse set of Fusobacteria sequences, many of which were closely related to *Cetobacterium sonerae*. The findings suggest that the gut microbiota of zebrafish is shaped by selective pressures within the host gut habitat, despite differences in host provenance and domestication status. This research highlights the potential of zebrafish as a model for studying host-microbiota interactions and the development of effective strategies for manipulating gut microbial communities to promote host health.The study by Roeseler et al. investigates the gut microbial communities of zebrafish, both those recently caught from their natural habitat and those reared in laboratory facilities. The researchers used 16S rRNA gene sequencing to compare the gut microbiota of these two groups of zebrafish. They found that the gut microbiota of domesticated zebrafish varied across different lab facilities, reflecting historical connections between these facilities. However, the gut microbiota of recently caught zebrafish was strikingly similar to that of domesticated zebrafish, suggesting a shared core gut microbiota. The study also identified specific bacterial taxa, particularly members of the γ-Proteobacteria and Fusobacteria classes, that were consistently present in the gut microbiota of zebrafish and other teleost fish species. Phylogenetic analysis revealed a diverse set of Fusobacteria sequences, many of which were closely related to *Cetobacterium sonerae*. The findings suggest that the gut microbiota of zebrafish is shaped by selective pressures within the host gut habitat, despite differences in host provenance and domestication status. This research highlights the potential of zebrafish as a model for studying host-microbiota interactions and the development of effective strategies for manipulating gut microbial communities to promote host health.