The planet's most powerful electric eel has been discovered lurking in the waters of the Amazon basin.
Electrophorus voltai can deliver an 850 volt shock, scientists have learned, well above the previous known high of 650 volts.
To put that into perspective, defibrillators commonly zap heart failure patients with anything between 200 volts and 1,700 volts.
E.voltai is one of two new species of eel in the Amazon, tripling the number of known electric eels.
“These fish grow to be seven to eight feet long. They’re really conspicuous,” said lead researcher David de Santana at the Smithsonian National Museum of Natural History.
“If you can discover a new eight-foot-long fish after 250 years of scientific exploration, can you imagine what remains to be discovered in that region?”
About 250 species of electricity-generating fish are known to live in South America, although electric eels (which actually are fish with a superficial eel-like appearance) are the only ones that use their electricity to hunt and for self-defence.
Like other electric fishes, they also navigate and communicate with the electricity they produce.
Smithsonian scientists have been collaborating with researchers at the University of São Paulo’s Museum of Zoology in Brazil and other institutions around the world to explore the diversity of the eels and other electric fishes in South America.
E.voltai primarily lives further south on the Brazilian Shield, a similar highland region.
Electrophorus varii, the other new species, named after the late Smithsonian ichthyologist Richard Vari, swims through murky, slow-flowing lowland waters.
The long recognised Electrophorus electricus, once thought to be widely distributed across the continent, actually appears to be confined to the highlands of the Guiana Shield.
Based on genetic comparisons, de Santana and his colleagues believe the two groups of eels began to evolve some seven million years ago.
According to the analysis, E. voltai and E. electricus diverged around 3.6 million years ago, around the time the Amazon River changed course, crossing the continent and traversing highland regions.
He said Voltai's super-charge may have been developed over time to adapt to the lower conductivity of highland waters.
Because the three species of electric eels diverged from one another so long ago, they may have evolved unique systems for electrogenesis, and, in the case of E. voltai,, this system is entirely unexplored.
“It could really have different enzymes, different compounds that could be used in medicine or could inspire new technology,” added de Santana.