From September 14th to 21st 2026, Fabien Chevalier, Ellyne Liégeois, Liz Cooney, Johan Decelle and Laia Burgues Palau went to the Bay of Villefranche-sur-Mer (NW Mediterranean) for a sampling campaign as part of our ERC project and EMBO Project (Liz). We were hosted by EMBRC at the marine station of Villefranche (CNRS – Sorbonne University). Most mornings we collected plankton from the boat with fine-mesh nets close to shore. We focused on acantharia and dinoflagellates, single-celled marine organisms that can live in symbiosis with microalgae. Back in the lab, we kept the cells alive and studied them using time-lapse, confocal, light-sheet and expansion microscopy. We also tested oxygen microsensors to measure how this photosymbiosis works in living cells. These samples will support Laia’s PhD research on how the host and its symbionts interact.

We are grateful to all the team members of EMBRC at the host institute (Julien Lopez Pardo, Alessandra Contento and the boat captain Cyril Debost), as well as the imaging facility (Margaux Failla) for the fantastic images produced during this campaign.

We also deeply thank our funders – the ERC SymbiOCEAN (EU), the EMBO fellowship and MITI funding for Liz.