Pearl oyster bacterial community structure is governed by location and tissue-type, but Vibrio species are shared among oyster tissues

Diseases of bivalves of aquacultural importance, including the valuable Australian silver-lipped pearl oyster (Pinctada maxima), have been increasing in frequency and severity. The bivalve microbiome is linked to health and disease dynamics, particularly in oysters, with putative pathogens within the Vibrio genus commonly implicated in oyster diseases. Previous studies have been biased towards the Pacific oyster because of its global dominance in oyster aquaculture, while much less is known about the microbiome of P. maxima. We sought to address this knowledge gap by characterising the P. maxima bacterial community, and we hypothesised that bacterial community composition, and specifically the occurrence of Vibrio will vary according to the sampled microenvironment.