Beware "Piranhagators"!

Piranhas are razor-toothed carnivorous fish of the Amazon waterways. In movies, piranha schools ferociously attack anything in the water. Most piranha, however, are scavengers. Global warming of the Amazon waterways causing evaporation leaves the water with increased salinity in addition to being warmer. Unfortunately, the amount of oxygen dissolved in water depends on temperature and salinity. Warmer, higher salinity water holds less oxygen. Less oxygen in the Amazon waterways means piranha and the fish they feed on will have difficulty surviving! To adapt, piranha may develop a respiratory system to breathe air from the atmosphere. It may also develop limbs from its fins to approach prey on land! Similar adaptations occurred 395 million years ago that led to the evolution of amphibians as shown in the figure. Who knows, someday piranha may walk on land and attack their prey in small groups! They might be renamed piranhagators!