Abstract The 1986 Chernobyl disaster created a distinct ecological niche characterized by ionizing radiation fluxes lethal to most higher life forms. Yet, within the darkened, highly radioactive interior of the destroyed Reactor No. 4, a specific guild of filamentous fungi has not only survived but thrived. First documented during the "Complex" expedition of the early 1990s by researchers employing remotely operated robotic platforms, these organisms—primarily Cladosporium sp