Catfish range from tiny aquarium species to enormous river fish weighing hundreds of pounds. The biggest verified catfish ever documented was a 646-pound Mekong giant catfish caught in Thailand in 2005. However, “biggest catfish” can mean several things: the heaviest individual, the longest fish, the largest species, or the largest catfish caught by an angler. Understanding these categories helps explain why Mekong giant catfish, Wels catfish, blue catfish, and flathead catfish may all appear in record lists.
What Is the Biggest Catfish in the World?
The Mekong giant catfish (Pangasianodon gigas) is generally recognized as the world’s heaviest documented catfish species. It is native to the Mekong River basin in Southeast Asia.
FishBase reports a maximum length of about 3 meters and a published maximum weight of 350 kilograms. However, the largest carefully documented individual weighed 293 kilograms, or 646 pounds.
| Feature | Mekong giant catfish |
| Scientific name | Pangasianodon gigas |
| Maximum reported length | About 3 m or 9 ft 10 in |
| Maximum published weight | 350 kg or 772 lb |
| Largest verified specimen | 293 kg or 646 lb |
| Verified specimen length | 2.7 m or 8 ft 11 in |
| Native range | Mekong River basin |
| Conservation status | Critically Endangered |
Adult Mekong giant catfish are unusual because they lose most of their teeth and barbels as they mature. Despite their enormous bodies, adults mainly consume algae and other plant material rather than hunting large animals.
Biggest Catfish Ever Caught
The biggest verified catfish ever caught was a female Mekong giant catfish captured in northern Thailand in June 2005.
The 646-Pound Mekong Giant Catfish
The fish measured approximately 8 feet 11 inches long and weighed 646 pounds. Local fishermen originally hoped to keep it alive for conservation purposes, but the fish died and was later distributed as food.
For years, it held the record as the largest documented freshwater fish of any species. In 2022, a 661-pound giant freshwater stingray caught in Cambodia surpassed it as the heaviest verified freshwater fish specimen. The Mekong giant catfish remains the largest verified catfish.
Species Size vs. Verified Catch
Reports sometimes claim that Mekong giant catfish can exceed 700 pounds. FishBase lists a published maximum weight of 350 kilograms, or about 772 pounds, but this does not mean a fish of that weight has been documented with the same record-level verification as the 2005 specimen.
Therefore, the clearest answers are:
- Largest verified catfish: 646-pound Mekong giant catfish
- Maximum published species weight: About 772 pounds
- Current largest verified freshwater fish: 661-pound giant freshwater stingray
Largest Catfish Records by Species
Record categories differ because some fish are weighed, some are measured and released, and others are captured through commercial or subsistence fishing rather than conventional rod-and-line angling.
| Catfish | Major verified record |
| Mekong giant catfish | 646 lb |
| Wels catfish | 297 lb 9 oz IGFA record |
| Blue catfish | 143 lb IGFA record |
| Flathead catfish | 123 lb IGFA record |
| Channel catfish | 58 lb world record |
Biggest Wels Catfish
The Wels catfish (Silurus glanis) is Europe’s largest freshwater fish and one of the longest living catfish species. The IGFA all-tackle weight record is 297 pounds 9 ounces, caught by Attila Zsedely in Italy’s River Po in 2010.
A Wels catfish measuring 2.92 meters, or approximately 9 feet 7 inches, was caught during a fishing competition in Poland in October 2025. Its estimated weight was between 120 and 130 kilograms. It represents a length record rather than a heavier catch than the 646-pound Mekong giant catfish.
Biggest Blue Catfish
The blue catfish (Ictalurus furcatus) is the largest major catfish species native to the United States. The current IGFA all-tackle record is 143 pounds, or 64.86 kilograms.
Blue catfish inhabit major river systems and deep reservoirs. They are powerful predators that consume fish, crayfish, freshwater mussels, and other available animals.
Biggest Flathead Catfish
The world-record flathead catfish weighed 123 pounds and measured 61 inches. Ken Paulie caught it at Elk City Reservoir in Kansas in May 1998 using a minnow and jig. The Kansas Department of Wildlife and Parks recognizes the fish as both the state and world record.
Flathead catfish have wide, flattened heads and projecting lower jaws. Unlike many scavenging catfish, they strongly prefer live prey, especially fish.
Biggest Channel Catfish
The world-record channel catfish weighed 58 pounds. W. H. Whaley caught it in South Carolina’s Lake Moultrie in 1964. It remains both the South Carolina record and the recognized world record.
Channel catfish are among North America’s most familiar catfish, but most adults are much smaller than this exceptional specimen.
What Is the Biggest Catfish in the United States?
The blue catfish holds the heaviest recognized U.S. catfish record at 143 pounds. The flathead catfish follows at 123 pounds, while the channel catfish record stands at 58 pounds.
Blue catfish are naturally associated with the Mississippi, Missouri, and Ohio river systems, although they have been introduced elsewhere. They can exceed 100 pounds when they have abundant food, suitable habitat, and enough time to grow.
State and river records may differ from world records. A fish described as the biggest catfish caught in the Mississippi River, Ohio River, Texas, Missouri, or Tennessee may be a local record without being the largest of its species worldwide.
Why Can Catfish Grow So Large?
Giant catfish usually live in extensive river systems that provide deep water, productive feeding areas, and enough space for seasonal movement.
Large River Habitats
The Mekong River supports numerous exceptionally large fish species. Its warm climate and productive floodplains provide year-round feeding opportunities, while connected river channels traditionally allowed fish to travel between feeding and spawning areas.
Blue and flathead catfish also grow larger in major rivers and reservoirs where they can find deep holes, submerged structures, and abundant prey.
Efficient Feeding
Different catfish use different feeding strategies. Blue and Wels catfish are active predators and opportunistic feeders. Flathead catfish capture live fish, while adult Mekong giant catfish mainly consume plant material.
Their sensitive barbels help many species locate food in dark or muddy water. Catfish also use strong senses of smell, taste, and vibration to find meals when visibility is poor.
Is the Mekong Giant Catfish Endangered?
The Mekong giant catfish is Critically Endangered. Overfishing, dams, habitat changes, and the disruption of long-distance migration routes have contributed to its decline.
Dams can block adult fish from reaching spawning grounds and change the timing and depth of river flows. The loss of floodplain habitats can also reduce feeding areas for young fish.
Recent catches do not necessarily indicate that the species has recovered. Six rare Mekong giant catfish were captured and released in Cambodia during several days in December 2024, including individuals weighing 120 and 131 kilograms. Researchers considered the event encouraging but emphasized the species’ continuing conservation needs.
FAQs
What is the biggest catfish ever caught?
The largest verified catfish was a Mekong giant catfish caught in Thailand in 2005. It weighed 646 pounds and measured approximately 8 feet 11 inches long. It was also the largest documented freshwater fish until a heavier stingray was recorded in 2022.
What is the biggest catfish species?
The Mekong giant catfish is generally recognized as the heaviest catfish species. FishBase reports that it can reach about 3 meters long and has a published maximum weight of 350 kilograms, although the largest verified specimen weighed 293 kilograms.
What is the biggest catfish caught in America?
The recognized blue catfish world record is 143 pounds. Blue catfish are the largest major North American catfish, exceeding the 123-pound flathead record and the 58-pound channel catfish record.
Is a Wels catfish bigger than a Mekong giant catfish?
A Wels catfish may rival or exceed a Mekong giant catfish in length, but the Mekong giant holds the heavier verified specimen record. The 646-pound Mekong catfish was more than twice the weight of the current IGFA Wels record.
Can catfish grow larger than humans?
Yes. Mekong giant and Wels catfish can grow considerably longer than an average person is tall. However, exceptionally large individuals are rare, and many photos make fish appear larger through camera angle or by holding them closer to the lens.