Nanoarchaeum equitans

Nanoarchaeum equitans is a tiny, single-celled microorganism belonging to the archaeal domain, known for thriving in extreme environments like hot springs. Remarkably small—smaller than many bacteria—it depends on another microorganism, Ignicoccus, for essential nutrients and energy. Despite its minimal size and simplified genetic makeup, N. equitans provides insights into microbial life and symbiotic relationships in extreme conditions. Its existence highlights how organisms can adapt to and survive in some of Earth’s harshest habitats, offering valuable information about the diversity and evolution of microbial life.