When a slithery fish called the northern snakehead first showed up in a Maryland pond in 2002, the public became terrified.

Some called wildlife officials to ask if their children were safe. Bizarre stories spread about a predatory fish that walked on land and ate small puppies.

Three horror movies were even made about the snakehead sighting, one called "Frankenfish" with bloodthirsty, genetically engineered fish invading the quiet waters of the Louisiana Bayou.

Since then, the snakehead population has multiplied by thousands, and it can be found in at least a dozen states.

In Missouri, at least 18 northern snakeheads have been caught in the southeastern part of the state and recorded by the U.S Geological Survey.

They have been found in Bollinger, Dunklin, Stoddard and Wayne counties, with at least 15 caught just last year.

The invasive species, actually known for its ability to survive on land, has not turned out to be the monster it was originally thought to be. In much of the world, it is an important food source.

It is, however, considered an injurious species in the United States and cannot be possessed or transported live, according to the U.S. Fish and Wildlife Service. Authorities in all 50 states have a mandate to control the population with an effort to market it as a viable target for anglers.

The story of this invasive fish is still ongoing and research in other states could help Missouri. Anglers are encouraged to report the catch to the Missouri Department of Conservation. However, the native bowfin looks similar to the northern snake head and can be mistaken for it.  

What the snakehead is

The northern snakehead can weigh up to 12 pounds and grow to a length of up to 3 feet. It has a distinctive appearance with a long, cylindrical body and generally tan coloring with dark brown mottling.

Its teeth and jaw are sharp (like a pike or pickerel). The top of its head is concave, and its eyes are located far forward. It has extended diesel and anal fins, pelvic fins near the pectoral fins and large scales atop the head. Its snake-shaped head is what gave it its name. The native bowfin are commonly mistaken for snakeheads.

Northern snakeheads are called piscivores. “Piscivores is the word we use for fish that eat other fish, and in terms of invasive species, usually the ones we're most concerned about in terms of their impact on the ecosystem,” said Allison Peasecq, the director of the Great Rivers Cooperative Ecosystem Studies Unit and assistant professor at the University of Missouri. 

One of the snakehead’s most unique characteristics is its ability to breathe air through a specialized organ called the suprabranchial chamber. This enables the animal to gulp oxygen from the air through its mouth and absorb it immediately. Because of this adaptation, snakeheads may live in a wide range of low-oxygen, stagnant water environments, including muddy rivers, canals, ponds, and swamps. It can also survive short periods without water. 

This ability makes it particularly dangerous as an invasive species, as it can traverse between bodies of water, potentially spreading to new habitats with ease.

How it was discovered

A borrow ditch within the St. Francis River levees in Dunklin County in the bootheel in 2019 was the location of the first northern snakehead recorded in Missouri.

“We had one in 2019, and then two in 2023, and then we had 20 new records in 2024. I think we're going to continue to see it [the population] grow and spread as far north as they can go, until they run into barriers,” said Dave Knuthcq, a Missouri Department of Conservation fisheries management biologist who watches the progress of northern snakeheads.

I don't think the [northern] snakehead is going to be as bad as the invasive carp. They're not as prolific, and I don't know if they're going to have the impacts on the food chain that the silver carp do,” said Knuth. "We really are unsure - it's too new into the invasion."

In Maycq, Katerina Thorntoncq saw a northern snakehead at Wappapello Lake Spillwaycq near Poplar Bluff.

It was early afternoon and her father, Steven, had cast his line and was waiting for a bite.

He felt a tug and passed the fishing rod to his 9-year-old grandson Avery, who reeled in the fish.

“That's when we saw it and realized that there was something weird about it . . . I had a sinking feeling,” said Katerina Thorntoncq.

Noticing its coloring and pattern of a snake, the Thornton family googled the fishes characteristics and reported it to the Missouri Department of Conservation.

“It's a regular ecosystem system. You got to have a balance. So I would think, as long as they're not taking out too much . . . I don't think they'll bother it [the balance] too much,” said Katerina Thornton.

There is evidence the fish are breeding. The Missouri Department of Conservation found a northern snakehead less than a year old in Mingo Duck Creekcq just south of the bootheel in 2024. Missouri's population comes from Arkansas (population found in 2008). The fish is moving north partly because of floods and seasonal movements. The fish takes advantage of Missouri's wetlands to spawn. 

Missouri Department of Conservation’s Invasive Species Coordinator Angela Sokolowski arrived on the scene in 2022 and was working when the second northern snakehead was found in 2023. “It was a pretty big cause for concern, because it indicated that the first one wasn't just the fluke, and we knew that they were coming up from Arkansas,” Sokolowski said.

The problems it has caused

“It was in everybody's mind. They were on late night TV, people making jokes about them," said John Odenkirkcq, fisheries biologist for the Virginia Department of Wildlife Resources.  

'I mean, it was all kinds of like, this weird culture of snakehead stuff going on.”

The actual impact of northern snakeheads is still unknown.

“Some biologists say that there's no impact on largemouth bass; and then there's other scientists that say that they are having impacts on some of your native fauna,” said Knuth.

Research about northern snakeheads done in other states, particularly Virginia, could be key to understanding their ecological impact. “What we've learned over more than 20 years of looking at the abundance and distribution of [northern] snakeheads, is that in the areas where they have been the longest, they seem like they maxed out . . .

They occupy the same niche as largemouth bass, so habitats overlap at times, but in terms of their trophic level, that predator and that system, they're basically equals in terms of their functional value,” said Odenkirk.

However, Missouri waters are different from Virginia waters, being more open. In an ecosystem, there exists a sort of natural checks and balances system between the predators and the prey. Every ecosystem has a capacity to carry a certain amount of life, and there is a limited amount of resources.

“If we put another species, especially another predator, in that system, somebody is going to have a smaller slice of pie, essentially. And this is a species that has some real advantages,” said Sokolowski.

Despite the state’s efforts, monitoring northern snakehead populations has proven challenging. Missouri lacks traditional techniques to target this predator. Traditional fishing gear (such as gill nets) and electrofishing (a technique that stuns the fish for dip nets to catch them) are not effective. Most of the state’s occurrences come from anglers.

Without proven strategies to control the snakehead, Knuth emphasized the importance of public cooperation and awareness. The Missouri Department of Conservation has installed signs with a QR code along likely northern snakehead habitats. This allows anglers to report sightings directly to Knuth and Sokolowski.

Another issue is its similarity to the bowfin, a desirable fish for Missouri's ecosystem.

Pease stresses the importance of keeping our native bowfin in the ecosystem in order to maintain balance. She identifies ways to tell them apart by their fins.

“The easiest one is to look at the anal fin, which is the single fin that's on the bottom of the fish in front of the tail. It's really long in the snakehead, and it's short in the bowfin. So if it has a short anal fin, release it unharmed, because it's our native bowfin,” said Pease. 

Sokolowski urges that it is a matter of potential and one must factor in the changing climate. It is unknown how species, both native and invasive, will respond to the changes. It may result in more favorable conditions to northern snakeheads, or maybe vice versa, giving the native species an advantage.

“We want to prevent any invasives from coming into Missouri or spreading to new places in Missouri, and that applies to fish or insects or plants,” said Sokolowski. “And so we just ask that people don't release pets or aquarium species or bait.”

Last summer, Maryland officially rebranded it as the "Chesapeake Channa" to sound more appetizing. As of June, it was for sale in supermarkets for $16.99 a pound.