One Volta’s electric eel — able to subdue small fish with an 860-volt jolt — is scary enough. Now imagine over 100 eels swirling about, unleashing coordinated electric attacks.
Such a sight was assumed to be only the stuff of nightmares, at least for prey.
“This is hugely unexpected,” says Raimundo Nonato Mendes-Júnior, a biologist at the Chico Mendes Institute for Biodiversity Conservation in Brasilia, Brazil who wasn’t involved in the study. “It goes to show how very, very little we know about how electric eels behave in the wild.”
Group hunting is quite rare in fishes, says Carlos David de Santana, an evolutionary biologist at the Smithsonian’s National Museum of Natural History in Washington, D.C. “I’d never even seen more than 12 electric eels together in the field,” he says. That’s why he was stunned in 2012 when his colleague Douglas Bastos, now a biologist at the National Institute of Amazonian Research in Manaus, Brazil, reported seeing more than 100 eels congregating and seemingly hunting together in a small lake in northern Brazil.
Two years later, de Santana’s team returned to the lake to make more detailed observations. The nearly 2-meter-long eels lethargically lay in deeper waters during much of the day, the researchers found. But at dusk and dawn, these long streaks of black come together, swirling in unison to form a writhing circle over 100 strong that herds thousands of smaller fish into shallower waters.
Such a sight was assumed to be only the stuff of nightmares, at least for prey.
“This is hugely unexpected,” says Raimundo Nonato Mendes-Júnior, a biologist at the Chico Mendes Institute for Biodiversity Conservation in Brasilia, Brazil who wasn’t involved in the study. “It goes to show how very, very little we know about how electric eels behave in the wild.”
Group hunting is quite rare in fishes, says Carlos David de Santana, an evolutionary biologist at the Smithsonian’s National Museum of Natural History in Washington, D.C. “I’d never even seen more than 12 electric eels together in the field,” he says. That’s why he was stunned in 2012 when his colleague Douglas Bastos, now a biologist at the National Institute of Amazonian Research in Manaus, Brazil, reported seeing more than 100 eels congregating and seemingly hunting together in a small lake in northern Brazil.
Two years later, de Santana’s team returned to the lake to make more detailed observations. The nearly 2-meter-long eels lethargically lay in deeper waters during much of the day, the researchers found. But at dusk and dawn, these long streaks of black come together, swirling in unison to form a writhing circle over 100 strong that herds thousands of smaller fish into shallower waters.
