Reaching into an electric eel's mouth is not for the faint of heart (or the ungloved hand, for that matter). These voracious hunters can deliver a 600-volt shock to their enemies and Force-choke prey from afar. But hidden just behind that toothless grin lies a tool that gives electric eels yet another advantage over other aquatic predators: a giant, bulbous lung.


Yes, electric eels can breathe air, and in fact, they have to in order to survive life in their low-oxygen habitat. Native to South America's Amazon and Orinoco basins, they can be found in murky streams, where they feed not only on fish, but also on the occasional terrestrial passer-by.

Despite their serpentine appearance, electric eels are not actually eels at all. Their scientific classification (genus Electrophorus) puts them closer to carp and catfish on the tree of life. Because they can only extract about 20 percent of the oxygen they need from the surrounding muddy water, they have to surface every 10-15 minutes. 

"Because they do this, we can actually keep them out of water for a remarkable amount of time," says University of Central Florida zoologist Dr William Crampton, who has done extensive work on electric fishes. "They don't seem to mind at all." Much like our own lung tissue, the folds in their mouths are highly vascularised and can absorb oxygen from the air that passes over them.

In this clip from Electric Amazon, our latest production for Smithsonian Channel, Crampton and his team hike into the heart of the rainforest to take us up close and personal with these incredibly well-adapted animals. 

Top header image: Leif Hinrichsen