We’re excited to announce that our manuscript “Hidden genomic diversity drives niche partitioning in a cosmopolitan eukaryotic picophytoplankton” has been published in The ISME Journal (https://doi.org/10.1093/ismejo/wrae163). Xu et al recovered and analyzed 37 genomes from the picophytoplankton genus Bathycoccus, revealing four distinct evolutionary clades with well-differentiated ecological niches and biogeographic distributions shaped by environmental factors. The study uncovered clade-specific genomic traits contributing to niche adaptation, highlighted temperature as a major driver of genome diversification, and identified potential cold-adaptation mechanisms in polar-adapted clades, providing insights into the microdiversity and adaptive evolution of this crucial marine eukaryotic phytoplankton.