Viruses infecting phytoplanktonic algae are known to trigger and/or accelerate the end of these algal blooms in the natural environment (Flynn et al. 2022). Knowledge about these viruses is very fragmented, and their diversity seems to be vaster than imagined just a few years ago. Beyond the host-virus specificity, which is not proven, the mechanisms of infection and the modes of action of viruses remain poorly documented. Recent observations (Véron et al. 2023) highlight the presence of viral particles in cells within a new group of algae, the Pavlovophyceae, previously considered non-infected by viruses (Sandaa et al. 2022). These unicellular algae are cultured for feeding the early larval stages of molluscs (Ponis et al. 2006a,b). In biomass production cultures, also intended for the extraction of molecules of interest, maintaining a stationary growth phase is rarely achievable for periods of several months, forcing professionals to use discontinuous culture rotations and ultimately resulting in erratic production, leading to additional costs and production uncertainties. Furthermore, correlations are beginning to emerge between the warming of water masses and the viral infection of phytoplanktonic cells. This last point remains to be linked to the revealed effects of climate change on marine viruses (Danovaro et al. 2011, Demory et al. 2017).