Catania published his findings in the Proceedings of the National Academy of Sciences on Monday.
Despite laying to rest two-century-old mystery, Catania still has questions about the eels' behavior.
"For example, why would electric eels take the offensive, rather than retreating from a potential threat?" Catania wrote in the study. "Why would not hundreds of volts delivered to the surrounding water be a sufficient defense, without the need for a directed attack? What is the likely effect of this behavior on a potential predator? How might the behavior have evolved? Finally, what do these findings suggest about Humboldt's account from 1800."
In addition, scientists still do not understand how eels manage to avoid electrocuting themselves.