Fire amoeba discovered in California breaks eukaryotic heat limit

Researchers from Syracuse University have discovered a new species of amoeba, named ‘Incendiamoeba cascadensis’ or the ‘fire amoeba’, that thrives in extreme heat. Found in the geothermal springs of Lassen Volcanic National Park in California, the organism sets a new upper temperature limit for eukaryotes, which are complex organisms with specialized cells.

While it was previously believed that eukaryotes could not reproduce at temperatures exceeding 60°C, this amoeba can successfully divide at 63°C and remains motile at up to 64°C. The organism can survive temperatures as high as 70°C by becoming immobile and forming a protective outer layer, though it does not feed or reproduce at that level.

Genetic analysis revealed that the amoeba possesses a suite of genes specifically related to DNA stabilization, environmental sensing, and proteostasis. This discovery expands the scientific understanding of the thermal limits of complex life and suggests that eukaryotic diversity in extreme environments may be more widespread than previously thought.