Abstract

Over 1 000 Amazon fish species have a fascinating adaptation that enables them to live in extremely acidic lakes. François-Étienne Sylvain set out to understand the mechanism that led to the adaptation, which continues to stump experts today. Is the action of the beneficial bacteria that live in natural symbiosis with the fish the key to their resistance to extreme environmental conditions? The recent findings identify bacterial species that co-evolved with the fish living in the acidic lakes. The discovery is the first step to elucidate one of the fundamental mechanisms behind the vast biodiversity of Amazon fish species and could have significant impacts for disturbed ecosystem conservation.