# Incendiamoeba cascadensis, a new amoeba, divides at 63°C in a California hot spring

- Published: 2026-11-06 02:38 UTC
- Section: Life & Health › Biology & biochemistry
- Tags: Incendiamoeba cascadensis, fire amoeba, extremophile amoeba, eukaryote heat limit, Angela Oliverio, Lassen Volcanic National Park, geothermal spring organisms, Methanopyrus kandleri, cyst formation
- URL: https://realtech.media/news/rt-b6746dcdefd83208750b2ebd_incendiamoeba_cascadensis_a/

**Researchers led by Angela Oliverio found a eukaryote in Lassen Volcanic National Park that grows at 63°C, above the 60°C limit long assumed for such organisms.**

![Incendiamoeba cascadensis, a new amoeba, divides at 63°C in a California hot spring](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/0a4c6aa78696ec83.jpg)
*James St. John, Wikimedia Commons, CC BY 2.0*

American researchers have found an amoeba in a geothermal spring in Lassen Volcanic National Park, California, that lives and reproduces at 63°C, Kursor reports, citing Science Alert. [1] The organism was named Incendiamoeba cascadensis, the "fire amoeba of the Cascades". [1]

## Heat limit for eukaryotes

Eukaryotes are organisms whose cells contain a formed nucleus and organelles. The group includes animals, plants, fungi and protists. Until now they were considered highly sensitive to strong heat, and 60°C was regarded as their upper temperature limit. [1]

Prokaryotes, meaning bacteria and archaea, tolerate much harsher conditions. The archaeon Methanopyrus kandleri, which lives near deep-sea hydrothermal vents, stays viable at 122°C. [1] For eukaryotes, the discovery of the Cascade amoeba moves the previously accepted boundary of heat tolerance. [1]

## Laboratory tests of endurance

In laboratory experiments, a team led by biologist Angela Oliverio determined the limits of the new species. At 63°C the amoeba continued asexual division (mitosis). Above this threshold, cell growth stopped completely. [1]

At temperatures above 64°C the organism entered a protective state: it curled its single-celled body into a dense ball and formed a cyst. [1] After brief exposure to 70°C, the amoeba was able to recover and return to normal growth once cooled to 60°C. [1]

The absolute lethal limit for the species was 80°C, after which cellular structures are destroyed irreversibly. [1] The researchers suggest that other eukaryotes capable of surviving even higher temperatures may be hiding in unexplored corners of the planet. [1]

## Sources

1. [Курсор](https://cursorinfo.co.il/interest/uchenye-otkryli-ekstremofilnuyu-amebu-v-ssha-chem-ona-porazhaet)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-b6746dcdefd83208750b2ebd_incendiamoeba_cascadensis_a/