Arapaima fish synchronize their breathing to survive predators

The arapaima is one of the world's largest freshwater fish, but as juveniles, they face a lethal paradox. Because they possess both gills and a primitive lung, they must periodically surface to gulp air. This necessity makes them easy targets for birds and other terrestrial predators waiting at the water's edge. To mitigate this risk, these fish have evolved a sophisticated form of collective behavior known as cluster synchrony.