“Thunder fish” is a common name rather than one universal scientific species name. In U.S.-related searches, it can refer to the northern snakehead (Channa argus), an invasive freshwater fish. “Thunderfish” is also documented as a name for the European weatherfish (Misgurnus fossilis) and the electric catfish (Malapterurus electricus).
What Is a Thunder Fish?
Thunder fish is a common name, not a single scientific classification. That distinction matters because common fish names can describe different species depending on the country, source, or context.
For U.S. readers, the most important interpretation is the northern snakehead, scientifically known as Channa argus. Business Queensland lists “thunder fish,” “raigyo,” and “snakehead” as names for this species.
However, the spelling “thunderfish” has other established meanings. Wiktionary lists it as a common name for the European weatherfish (Misgurnus fossilis) and the electric catfish (Malapterurus electricus).
So if someone says “thunder fish,” the safest approach is to ask which fish and which region they mean.
Why “Thunder Fish” Can Mean Different Things
Fish often have several common names. These names can come from local languages, historical usage, appearance, behavior, or regional fishing traditions.
Scientific names solve much of this confusion. For example, Channa argus identifies the northern snakehead specifically, while Misgurnus fossilis identifies the European weatherfish.
That is why a search for “thunder fish” should not automatically be treated as a search for one species.
Thunder Fish vs. Thunderfish
The two spellings are closely related but can produce different search results.
“Thunder fish” is documented as another name for northern snakehead in some sources. “Thunderfish” is also recorded as a common name for European weatherfish and electric catfish.
If your search is about a fish caught in the United States, identifying the scientific name, appearance, and location is much more reliable than relying on the common name alone.
What Fish Is Called Thunder Fish?
There are several real-world fish associated with the term.
| Fish | Scientific name | Why it matters |
| Northern snakehead | Channa argus | “Thunder fish” is listed as another name |
| European weatherfish | Misgurnus fossilis | “Thunderfish” is a documented common name |
| Electric catfish | Malapterurus electricus | “Thunderfish” is also documented as a common name |
Northern Snakehead Channa argus
The northern snakehead is the most important interpretation for a U.S.-focused article. U.S. Fish & Wildlife Service identifies Channa argus as the scientific name for northern snakehead, while U.S. Geological Survey describes snakeheads as air-breathing freshwater fishes that are not native to North America.
The species is native to parts of Asia, including China, Russia, and Korea, and has established introduced populations in parts of the United States.
European Weatherfish Misgurnus fossilis
The European weatherfish is a different animal. FishBase identifies Misgurnus fossilis as weatherfish and places it in the loach family Cobitidae. It is a freshwater and brackish species found across parts of Europe and Asia.
FishBase reports a maximum recorded total length of about 30.7 cm for the species. It commonly lives in slow-flowing rivers, ponds, pools, and ditches and can burrow into mud.
Electric Catfish Malapterurus electricus
The electric catfish is another completely different fish.
FishBase identifies Malapterurus electricus as an African freshwater electric catfish. It occurs in several African river and lake systems and uses an electric organ for prey capture and defense.
This species is capable of producing substantial electrical discharges, so it should not be confused with the northern snakehead simply because both can appear under related common-name terminology.
Is Thunder Fish the Same as a Snakehead?
In some sources, yes. “Thunder fish” is listed as another name for the northern snakehead (Channa argus). Business Queensland lists snakehead, raigyo, and thunder fish as other names for the species.
But not every use of “thunderfish” means snakehead. Dictionary sources also use the term for European weatherfish and electric catfish.
For a U.S. search, therefore, it is useful to investigate whether the person means northern snakehead.
Northern Snakehead Scientific Name
The scientific name is Channa argus.
U.S. Fish & Wildlife Service lists:
- Common name: Northern snakehead
- Scientific name: Channa argus
- Genus: Channa
- Family: Channidae
Using the scientific name is the best way to remove ambiguity.
Why Is It Also Called Raigyo?
Raigyo is another common name associated with northern snakehead. Business Queensland lists both raigyo and thunder fish among the species’ other names.
Common names can vary considerably between regions. That is why an article or fishing report using “thunder fish” should ideally provide the scientific name when discussing a specific species.
What Does a Northern Snakehead Look Like?
Northern snakeheads have a long, streamlined body and a relatively large, flattened head. Their bodies can show distinctive dark, python-like markings, which is one reason the fish received the name “snakehead.” U.S. Fish & Wildlife Service also notes the species’ long anal fin and scales on top of the head.
Business Queensland describes the northern snakehead as a long, slender fish with a torpedo-shaped body, a single dorsal fin extending along much of the body, and brown coloration with dark blotches.
Key Identification Features
Look for these characteristics:
- Long, slender body
- Flattened head
- Large mouth
- Dark, irregular or python-like body markings
- Scales on the top of the head
- Long dorsal and anal fins
- Pelvic fins positioned close behind the pectoral fins
The exact appearance can vary with age and conditions, so identification should not rely on one feature alone.
Thunder Fish vs. Bowfin
One of the most important U.S. identification issues is distinguishing a northern snakehead from the native bowfin.
| Feature | Northern Snakehead | Bowfin |
| Status in U.S. | Invasive/non-native | Native |
| Body pattern | Strong, python-like patterning | Usually less patterned |
| Head scales | Present | Absent |
| Anal fin | Long | Short |
| Pelvic fins | Close to pectoral fins/gills | Set farther back |
| Native range | Asia | Eastern North America |
U.S. Fish & Wildlife Service specifically warns that snakeheads can be confused with native bowfin and provides these identifying differences.
Do not remove or report a native bowfin as a snakehead based on appearance alone. If you are unsure, photograph the fish and contact the appropriate state wildlife agency for identification.
Where Is Thunder Fish Found in the USA?
If by “thunder fish” you mean northern snakehead, the species has established populations in several parts of the United States.
U.S. Fish & Wildlife Service’s current ecological-risk summary reports established Channa argus populations in Delaware, Virginia, Maryland, Pennsylvania, New York, New Jersey, and Arkansas. It also notes that individual fish have been collected in several other states without established populations being confirmed there.
The species is particularly associated with the Mid-Atlantic, including the Potomac River system. U.S. Fish & Wildlife Service describes the northern snakehead as primarily found in the Mid-Atlantic among its U.S. invasive-fish information.
Chesapeake Bay and the Potomac River
Northern snakeheads became nationally prominent in the United States after captures in Maryland, including the famous 2002 Crofton pond discovery and subsequent findings in the Potomac River. USGS records the 2002 Maryland discovery and the later Potomac River detections in Maryland and Virginia.
The Potomac River and its connected waters remain an important area for northern snakehead management and monitoring.
Recent Expansion Into the Mississippi Basin
The U.S. distribution story is still developing.
A January 19, 2026 USGS publication documented a reproductive population of northern snakeheads in Missouri’s Saint Francis River drainage. Researchers described increasing captures in the Mingo Basin and identified the area as connected to the Upper Mississippi River system.
This matters because an old list of states should not be treated as a permanent map. Snakehead distribution can change as populations expand or are detected.
Is Thunder Fish an Invasive Species?
The answer depends on which fish you mean.
The phrase “thunder fish” itself is not an invasive-species classification. However, northern snakehead (Channa argus) is considered an invasive species in the United States. USGS states that snakeheads are non-native to North America and have the potential to threaten native fishes, recreational fishing, and aquatic ecosystems.
Northern snakeheads have several biological traits that help them persist in new environments.
They can:
- Breathe atmospheric air
- Tolerate poorly oxygenated water
- Live in ponds, swamps, streams, canals, reservoirs, lakes, and rivers
- Reproduce successfully in suitable habitats
- Tolerate a relatively broad range of environmental conditions
USGS’s Nonindigenous Aquatic Species database describes Channa argus as an obligate air-breather capable of surviving in poorly oxygenated waters.
Why Does That Matter?
A non-native predatory fish can interact with native species and food webs in ways that may be difficult to predict or manage.
That does not mean every body of water containing a snakehead will experience the same ecological effect. Local habitat, population size, prey availability, and management actions all matter.
The important point is that U.S. agencies treat established northern snakehead populations as an invasive-species management concern.
Can Thunder Fish Breathe Air?
If you mean northern snakehead, yes.
Northern snakeheads are air-breathing freshwater fish. Their ability to use atmospheric oxygen allows them to survive in poorly oxygenated water and contributes to their ability to persist in challenging aquatic environments.
U.S. Fish & Wildlife Service also reports that snakeheads can survive out of water for extended periods and can move across land under suitable conditions.
This ability is one of the reasons snakeheads are so unusual compared with many familiar North American freshwater fish.
It also means anglers should never assume that leaving a suspected snakehead on the bank will prevent it from returning to the water.
What Should You Do If You Catch a Northern Snakehead?
If you catch a fish you believe is a northern snakehead, do not automatically release it.
U.S. Fish & Wildlife Service advises anglers to:
- Do not release the fish.
- Do not simply throw it onto the bank, because it may survive and return to the water.
- Photograph the fish when possible.
- Record useful information such as the location, size, and number of fish.
- Contact the appropriate state conservation agency or U.S. Fish & Wildlife Service for guidance and identification.
Rules can vary by state, so follow the current regulations and instructions for the location where the fish was caught.
The most important step is correct identification. A native bowfin can resemble a snakehead, and mistakenly treating a native fish as an invasive one is exactly the problem good identification is designed to prevent.
What Is a Weatherfish?
The European weatherfish (Misgurnus fossilis) is a freshwater or brackish fish in the loach family Cobitidae.
FishBase reports the species across parts of Europe and Asia, where it can inhabit slow-flowing rivers, ponds, pools, and ditches. It can burrow into mud during unfavorable conditions and is a facultative air-breather.
FishBase lists a maximum recorded total length of approximately 30.7 cm.
This fish is not the northern snakehead.
The connection comes from common-name terminology: “thunderfish” is listed as a name for the European weatherfish.
What Is the Electric Catfish?
The electric catfish (Malapterurus electricus) is another species associated with the word “thunderfish.”
It is an African freshwater catfish found in several river and lake systems. FishBase describes it as a nocturnal predator that uses an electric organ for prey capture and defense.
Its electric organ can produce substantial discharges, which makes the species biologically very different from the northern snakehead and European weatherfish.
So when you see “thunderfish” in a dictionary or historical common-name source, don’t automatically assume the writer means a snakehead.
Is the Thunderfish From How to Train Your Dragon Real?
No. The Thunderfish from How to Train Your Dragon is fictional.
In Dragons: Race to the Edge, the Thunderfish is revealed to be a Scauldron, a fictional water dragon. The character appears in the episode “In Plain Sight.”
That is a separate use of the word from the real fish discussed in biology and fishing resources.
This distinction is important because searches for “Thunderfish” can mix real-world fish information with entertainment-related results.
How to Interpret the Name “Thunder Fish” Without Misidentifying the Fish
A simple way to handle the term is the Name → Scientific Name → Region method.
1. Start with the name
If someone says “thunder fish,” don’t assume there is only one species.
2. Find the scientific name
If the fish is Channa argus, you’re dealing with the northern snakehead.
If it is Misgurnus fossilis, you’re dealing with the European weatherfish.
If it is Malapterurus electricus, you’re dealing with the electric catfish.
3. Check the region
Location provides another useful clue.
A U.S. fishing report mentioning a long, patterned invasive fish is much more likely to require investigation as a northern snakehead than as a European weatherfish.
This three-part check—Name → Scientific Name → Region—is more reliable than treating a common name as a taxonomic identity.
Conclusion
“Thunder fish” is a common name with more than one meaning. For U.S. readers, one important interpretation is the northern snakehead (Channa argus), an invasive freshwater fish that can breathe air and has established populations in several states. But “thunderfish” can also refer to the European weatherfish or electric catfish, so the scientific name and location should always be checked before identifying a fish.
FAQs
What is a thunder fish?
“Thunder fish” is a common name that can refer to different fish. In some sources, it is another name for the northern snakehead (Channa argus), while “thunderfish” is also documented for European weatherfish and electric catfish.
Is thunder fish a real fish?
Yes, but the name does not identify one universal species. It can describe different real fish depending on the source, including northern snakehead, European weatherfish, and electric catfish.
Is thunder fish the same as snakehead?
It can be. Business Queensland specifically lists thunder fish as another name for the northern snakehead, Channa argus. However, “thunderfish” has other documented meanings, so context matters.
What is the scientific name of thunder fish?
There is no single scientific name for every fish called thunder fish. If the term refers to northern snakehead, the scientific name is Channa argus. Other documented thunderfish meanings include Misgurnus fossilis and Malapterurus electricus.
Where are northern snakeheads found in the USA?
Established northern snakehead populations have been documented in states including Delaware, Virginia, Maryland, Pennsylvania, New York, New Jersey, and Arkansas. Recent USGS research published in 2026 also documented a reproductive population in Missouri’s Saint Francis River drainage.
Are thunder fish dangerous to humans?
If you mean northern snakehead, the main U.S. concern is ecological, not that the fish is a dangerous predator of people. U.S. agencies focus on its invasive status, potential effects on native fish and ecosystems, and appropriate handling and reporting.
Can snakeheads breathe air?
Yes. Northern snakeheads are air-breathing freshwater fish and can survive in poorly oxygenated water. This adaptation contributes to their ability to persist in a range of aquatic environments.
What should you do if you catch a northern snakehead?
Do not release a suspected northern snakehead without checking the applicable state guidance. U.S. Fish & Wildlife Service recommends photographing the fish, documenting its location and contacting the relevant conservation agency or USFWS for identification and reporting.
Is the Thunderfish from How to Train Your Dragon real?
No. The Thunderfish in Dragons: Race to the Edge is a fictional Scauldron, not a real biological fish species.
