More precisely, the miniscule archaea attach themselves to the cell membranes of their heat-loving or “thermophilic” Acidilobus hosts. Over time, the little thieves steal all the nutrients they need that are cycling through the host’s cell membrane, which keeps them alive and healthy for as long as the host remains alive.
ORNL explain how they cultured the fragile, demanding extremophiles in their laboratory. Oak Ridge National Laboratory via YouTube
When the host dies, the N. acidilobi can detach from it, drift around for a while, and eventually find a new host to latch on to. No benefit to the host could be seen, which means that this relationship is either commensal, where the host gives up some of its nutrients but isn’t harmed doing so, or ectoparasitic, wherein some harm is done to the host over time. Currently, it’s not clear which is more appropriate, although both are possible depending on the zealousness of the little piggybacker.
- N. acidolobi is compared by the researchers to Nanoarchaeum equitans, another type of marine archaea discovered in a hydrothermal vent off the coast of Iceland back in 2002. Both are thermophilic and survive in very acidic environments, which makes them extremophiles – organisms that do not just survive, but thrive in extreme settings. In fact, it’s thermophiles like these that actually help produce some of the bright colors of Yellowstone’s most famous hot springs.
- Yellowstone's Grand Prismatic Spring, whose bright colors are mostly down to the thermophilic microbes hiding within it. Jim Peaco, Naitonal Park Service