New research shows that Candidatus Nanohaloarchaeum antarcticus, a DPANN archaeon from an Antarctic hypersaline lake called Deep Lake, behaves like a parasitic predator that rapidly kills its host, Halorubrum lacusprofundi. Electron microscopy showing Candidatus Nanohaloarchaeum antarcticus attached to its host, Halorubrum lacusprofundi. Image credit: Joshua N. Hamm. “Archaea is one of three lineages of life, alongside Bacteria and Eukarya (organisms...