These Large, Snake-Like Fish Are Invading the United States—and Authorities Want You to Kill Them Invasive northern snakeheads can “walk” on land, breathe air and survive out of water for several days, and they also compete with native species in waterways Northern snakeheads were first discovered in American waters in 2002. U.S. Fish and Wildlife Service It may sound like something out of science fiction: A three-foot-long fish that can breathe air, “walk” on land and survive for days out of the water. But the northern snakehead is very real—and, perhaps more importantly, it’s very invasive. As fishing season gets underway, officials are asking anglers to keep an eye out for these scary-looking swimmers. And, if anyone does happen to catch some northern snakeheads, authorities have requested they kill the invasive creatures—by either chopping their heads off, gutting them or placing them in a sealed plastic bag. As for which method is best? “I guess it’s personal preference,” says Angela Sokolowski, the Missouri Department of Conservation’s invasive species coordinator, to the New York Times’ Victor Mather. Northern snakeheads have sharp teeth and python-like coloring and patterns. U.S. Geological Survey Originally hailing from Asia, the northern snakehead (Channa argus) has been proliferating throughout the United States for the last two decades. They have sharp teeth and scales that are similar in coloring and pattern to pythons. In 2002, the species was found in American waters for the first time in Crofton, Maryland, likely having spread from the fish market or aquarium trades. Since then, it’s been spotted in New York, Pennsylvania, New Jersey, Arkansas and beyond. In Missouri, the first northern snakehead turned up in 2019 in a ditch in the state’s southeastern region. Now, sightings of the fish in that area are reportedly on the rise. Snakeheads were previously sold in pet stores, live fish markets and some restaurants. Some “aquarium hobbyists” or snakehead connoisseurs may have released them in hopes of establishing a local source of food, per the U.S. Geological Survey. But those fish—let into the wild outside their native habitat—have become problematic. They are “aggressive predators,” according to the Missouri Department of Conservation’s recent alert to residents. They can reproduce and grow rapidly, crowding out native species by gobbling up small fish, crustaceans and other critters. This could make them a threat to commercial and recreational fishing.Their air-breathing abilities also give them some unique advantages. In addition to being able to survive on land, northern snakeheads can live in muddy, shallow waters that don’t have a lot of oxygen—ecosystems that are typically off-limits to other fish that exclusively absorb oxygen through their gills. Female northern snakeheads can carry up to 50,000 eggs, many of which will hatch one to two days after being fertilized. The fish typically shy away from humans. But once their eggs have hatched, northern snakeheads can turn nasty. Both the male and female parents guard their young—called fry—and have been known to aggressively defend them against any possible threats. Under federal law, the northern snakehead is considered an “injurious” species. That means it’s illegal to import, export, sell or purchase the fish or transport one across state lines. But after fishing and killing a northern snakehead, you are allowed to take it home and cook it—the Maryland Department of Natural Resources, for one, recommends it, and describes their filets as “mild, flaky and generous.” (The northern snakehead is one of several invasive species that wildlife authorities have encouraged people to eat as a means of population control.)Officials in several states are encouraging anglers to take photos and report any northern snakeheads they catch, making note of the location. Snakeheads are often confused with a native species—the bowfin—but anglers can tell them apart by looking at the anal fin, which is much longer on a snakehead. Bowfins have a dark splotch on their tails and lack the python-like spots of the invasive species. “Although it is doubtful that complete eradication can be achieved, control efforts have been successful,” according to the U.S. Fish and Wildlife Service. “With the help of the public, we can continue to control populations of northern snakehead where they exist, which should help minimize future negative impacts.” Get the latest stories in your inbox every weekday.