The invasive northern snakehead fish is spreading through Missouri.
A fourth snakehead was caught late last month by an angler in Wayne County, according to the state’s Department of Conservation. The department on Tuesday received a confirmed fifth snakehead sighting, which was witnessed on May 24 in the Mingo National Wildlife Refuge.
Native to Asia, the invasive species is an aggressive predator that preys on native species and competes with them for resources.
Dave Knute, a fisheries biologist with the Missouri Department of Conservation, said that while he doesn’t think the snakeheads will have harmful effects as significant as those of other invasive species, like the silver and bighead carp, they may still cause problems to native ecosystems.
“They are a ferocious predator that eats almost anything,” Knute said. “They are very good at being invasive, they have high parental care, they have a lot of young they can produce. They’re going to be competing for food and space with our native fishes.”
The invasive species isn’t yet confirmed to be established in Missouri waters, since only a few have been spotted and there aren’t major signs of reproduction. To keep the species from getting out of control, Knute said it’s important to keep the public informed about the issue.
“These fish, they like shallow, muddy substrate, lots of vegetation. They’re very hard to either angle or sample, so with our conventional fishery gear, they are hard to capture,” he said. “I think our best defense is education.”
Northern snakeheads can grow up to three feet long, have a head that resembles a snake and can breathe air, allowing them to survive for days on land. They have a python-like coloration and pattern. They can move across land to return to water.
Knute said the snakeheads are coming from Arkansas, which has been battling them since 2008. He said he expects them to travel to other states in the Midwest through the Mississippi River.
Katie O’Reilly, an aquatic invasive species specialist with the Illinois-Indiana Sea Grant and the Illinois Natural History Survey at the University of Illinois, said there have been no sightings of the northern snakehead in Illinois since 2004, but she’s not ruling out the possibility of more appearing in the future.
“We do have a big concern that they could get into the Great Lakes, which have already had their own issues with invasive species,” O’Reilly said. “We’re trying to prevent that from ever being the case.”
She said that native ecosystems already have stressors, including pollution from humans and changes in weather patterns, and that invasive species, like northern snakeheads, add to that stress.
“In order to have a balanced ecosystem, you want to try and minimize the impacts of those stresses,” O’Reilly said. “Like any invasive species, if the northern snakehead gets out of control or gets really firmly established somewhere, we can see cascading impacts on aquatic ecosystems and the things that we really value about our rivers and lakes.”
Both O’Reilly and Knute said that the northern snakehead often gets confused with the bowfin, a native species that’s beneficial to Missouri’s rivers and lakes, and that people should educate themselves on the differences between the fish before capturing them.
The Missouri Department of Conservation said it will monitor the spread of northern snakeheads. The first was captured in the state in 2019, and two more were caught last year.
When a northern snakehead is caught, the department advises against releasing it back into the water or leaving it on land, since it can breathe air. The department recommends killing the fish or placing it in a sealed plastic bag, photographing it and noting the location where it was caught. Any catches or sightings of the fish should be reported to the department’s Southeast Regional Office at 573-290-5730, officials say. More information can be found on its website.
