By Watershed Protection Program Co-op Sally Ehlers
The northern snakehead (Channa argus) is a type of fish that is originally from Asia which has made its way to Pennsylvania and is causing problems in local streams. In 2004, an angler found a northern snakehead in Meadow Lake in FDR Park in Philadelphia County. This was the first confirmed sighting of this type of fish in Pennsylvania.
About a year later, there was a recorded catch in the Delaware River. They have since spread through canals, reservoirs, lakes, and rivers along the East Coast and as far west as the Mississippi River. The presence of the northern snakehead is worrisome because it can be harmful to other fish and their homes. The northern snakehead is a voracious predator and eats other fish. This aggressive behavior can reduce the number of other fish in a waterway. Northern snakeheads will compete with other fish for food and habitat.
One thing that makes the northern snakehead unique is its ability to survive in water with many different levels of dissolved oxygen. Even if there is not a lot of dissolved oxygen in the water, the northern snakehead can still survive. This is because it has a special organ called a suprabranchial organ, or primitive lung. This organ allows the northern snakehead to breathe air directly from the atmosphere. They can even survive out of water for up to four days if they stay moist. This adaptation, in combination with its ability to move across land for short distances by wriggling on its fins, allows it to easily travel from one body of water to another.
To stop the northern snakehead from spreading, the Pennsylvania Fish and Boat Commission has made some rules:
- Do not keep or sell northern snakeheads.
- Do not release them into other bodies of water.
This ensures the northern snakehead does not continue to spread.
The Pennsylvania Fish and Boat Commission is also working hard to teach people how to identify the northern snakehead. If people know what to look for, they can help make sure it doesn’t spread to other areas. The northern snakehead has some distinctive features, such as a long body with a single fin running along the length of the back, a somewhat flattened head, and a brown body with dark blotches.
The northern snakehead can be confused with the native North American Bowfin (Amia calva). In the western part of Pennsylvania, northern snakeheads may also be confused with burbot (Lota lota). These species have similar body shapes and coloration, however, there are some key differences. As the name implies, the northern snakehead has enlarged snake-like scales on its head. The Northern American Bowfin does not have scales on its head, rather it has bony plates between its lower jaw bones. The burbot has a scaly head, but unlike the northern snakehead, it has two fins on its back.
If you catch a northern snakehead, it is essential to report it to the Pennsylvania Fish and Boat Commission by calling 815-359-5163 or visiting their website. You are also encouraged to kill it, freeze it, and record the location where you found it. This information is useful for figuring out the geographic range of the northern snakehead and possibly finding ways to control its spread.
“California’s Invaders: Snakehead,” California Department of Fish and Wildlife,
“Northern Snakehead,” Chesapeake Bay Program,
“Northern Snakehead,” Pennsylvania Fish and Boat Commission,
“Northern Snakehead,” Pennsylvania Sea Grant, https://seagrant.psu.edu/sites/default/files/snakehead2013_reduced_0.pdf
“Northern Snakehead Fish,” Smithsonian’s National Zoo and Conservation Biology Institute, https://nationalzoo.si.edu/animals/northern-snakehead-fish