"Fire Amoeba" Sets New Heat Tolerance Record Among Eukaryotes
Researchers have discovered what may be the most heat-tolerant eukaryotic organism ever documented. The newly described amoeba, named Incendiamoeba cascadensis, can not only survive but actively replicate at temperatures reaching 145°F (approximately 63°C), shattering the previous heat tolerance record for organisms with nucleated cells.
The discovery is notable because eukaryotes—the domain of life encompassing plants, animals, and fungi—have generally been understood to face stricter thermal limits than simpler organisms like bacteria or archaea. Most eukaryotic life thrives far below such extreme temperatures, with human cells beginning to fail around 107°F.
Incendiamoeba cascadensis was found in geothermal regions, suggesting it evolved adaptations that allow its cellular machinery—including proteins, membranes, and genetic material—to remain functional under conditions that would denature the biology of most known life forms. Understanding these adaptations could inform studies ranging from astrobiology to biomedical research.
The findings expand the known boundaries of eukaryotic biology and raise questions about how life persists in extreme environments on Earth—and potentially elsewhere in the solar system.