The project aims at investigating the vent mussel B. azoricus long term acclimatization at sea-level environmental conditions, using a transcriptomics approach to analyze the relative abundance of host-symbiont related RNA transcripts. The project provides insights into molecular mechanisms driving gill (host) –symbiont interactions and gill microbiome shifts during aquaria adaptation over 5 weeks period during which 11 RNA samples were taken from distinct time points. Results put in evidence mussel’s physiological reactions during hypothetical venting inactivity.