When invasive snakehead fish first appeared in the United States, in 2002, the secretary of interior herself called a press conference to warn of impending danger. “These fish are like something from a bad horror movie,” she told reporters. “They can eat virtually any small animal in their path. They can travel across land and live out of water for at least three days. They reproduce quickly.” What’s more, they can breathe air, and they have razor-sharp teeth. The interior department banned the importation of snakeheads to the U.S.
Meanwhile, National Geographic dubbed the snakeheads “fishzilla.” They inspired actual bad horror movies, with titles such as Frankenfish and Snakehead Terror. And as snakehead fish have continued to spread to new parts of the U.S., most recently Georgia, the advice has been blunt and unsparing: “Kill it immediately.”
But after almost two decades in the U.S, the horror of the snakehead fish has not come to pass. They’ve had little ecological impact on most of their new habitats. They definitely haven’t chased any humans around on land. (Hello, Frankenfish.) In fact, after all that hype, it’s not even clear how well the species in the U.S., the northern snakehead fish, can travel across land—if at all.
That’s how Noah Bressman, a graduate student at Wake Forest University, ended up spending the summer of 2018 catching northern snakeheads and trying to coax them out of the water. He was surprised, he told me, to find nothing in the scientific literature about how northern snakeheads move on land. The Interior Department’s ominous 2002 press conference had lumped together all snakeheads, which comprise a whole family of fish species found in Asia and Africa. Some were known to move on land. Others, such as the northern snakehead fish, were less studied.