Aquatic environments comprise the largest habitat on the planet. Over the last 4 billion years, microbes have evolved to become an integral component of aquatic ecosystems by developing complex trophic interactions known as aquatic food webs. In a natural ecosystem all trophic constituents evolve in the context of these interactions; while prey/host develops resistance the predators/parasites continuously develop strategies to bypass these resistances, resulting in a co-evolutionary arms race. Parasites fine-tune the dynamics, abundance, and micro-diversity of their host in the ecosystem. Moreover, they facilitate the transfer of carbon via their top-down control over host and hence play a role in biogeochemical cycles. Many of these mechanisms are unknown but represent potential tools that can be harnessed for environmental management and biotechnology. Despite our remarkable advances in understanding the diversity of aquatic bacteria and archaea via high throughput sequencing technologies, we are still far from fully comprehending their interactions with other constituents of the food web and this must be elucidated. My overarching research interest is to understand the functional and evolutionary basis of multipartite parasitic interactions specifically in freshwater ecosystems. My approach is to combining integrated analysis of freshwater multi-omics datasets with experimental strategies on cultured host-parasite model systems. I follow this research line within the scope of my Formas project and my incoming ERC starting grant.