Extremophile algae "Euglena Mutabilis" in the source of the river "Rio Tinto" in Spain. Euglena Mutabilis can survive in the highly acidic and toxic water of this river. Rio Tinto river, located in Spain, has been a very interesting research location for NASA, due to similarities to the Mars planet environment. Highly acidic environments are relatively scarce worldwide and are generally associated with volcanic activity and mining operation. Río Tinto is an unusual ecosystem due to its size (100 km long), rather constant acidic pH (mean value 2.3), high concentration of heavy metals (Fe, Cu, Zn, As, Mn, Cr, etc.) and high level of microbial diversity.

Javier Montero