The marine cave‐dwelling mysid H emimysis margalefi is distributed over the whole M editerranean S ea, which contrasts with the poor dispersal capabilities of this brooding species. In addition, underwater marine caves are a highly fragmented habitat which further promotes strong genetic structuring, therefore providing highly informative data on the levels of marine population connectivity across biogeographical regions. This...

Summary Osedax worms are whale‐fall specialists that infiltrate whale bones with their root tissues. These are filled with endosymbiotic bacteria hypothesized to provide their hosts with nutrition by extracting organic compounds from the whale bones. We investigated the diversity and distribution of symbiotic bacteria in Osedax mucofloris from shallow‐water whale‐falls in the North Atlantic using comparative 16S rRNA sequence...