There are big fish, and then there are giant fish. A 10-pound largemouth is a big fish. It might be a truly impressive specimen from the local reservoir. But that’s not what we’re talking about. We’re talking about giants large and ferocious enough to make a meal out of your personal-best largemouth.
In this world-wide round-up of monsters, we’ve selected and profiled a handful of the biggest and most sporting species that live in freshwater. Dig out your passport and gird your loins for some of the most violent, back-breaking fishing on the planet.
Pacific White Sturgeon- British Columbia
If size matters most, add white sturgeon to your bucket list. These western giants spend time in freshwater and salt, but they are known as North America’s largest freshwater fish. They grow perpetually through a century-long lifespan to top 10 feet in length with weights well over 1,000 pounds.
White sturgeon move between saltwater estuaries and freshwater rivers in a range that spans the Pacific coast from Mexico’s northern Baja to Alaska. Arguably the best white sturgeon fishery in the world is British Columbia’s Fraser River. For 30 years, the Fraser has been catch-and-release-only for this slow-growing giant. A 9-footer is the fish of a lifetime, says Kevin Estrada, of Sturgeon Slayers guide service, yet in 2021 he guided clients to an 11-foot, 6-inch (fork length) monster that is one of—if not the largest—rod-and-reel catch ever.
Estrada is notorious for putting the well-being of the fish ahead of client comfort. He fishes 200-pound braid with a 70-pound mono leader on Accurate Valiant 800s and cranks down the drag to apply lots of pressure and end fights quickly. It’s a sink-bait-and-wait fishery that explodes with action when a big fish eats a chunk of salmon, lamprey or a roe-bag on a barbless hook.
“Think about freshwater tarpon. They come flying out of the water, and they are very strong fish,” Estrada says.
Siberian Taimen – Mongolia
Mongolian terror trout, more formally known as Siberian taimen, are the largest most ferocious salmonids on the planet. Only the land of Genghis Khan could produce such a monster!
Actually, taimen have a large native range that stretches from eastern Europe across most of Russia and northern Asia. Mongolia just happens to be the epicenter of sport fishing for the species due to the country’s dedication to preserving the fish, which has had a hard time with pollution and overfishing elsewhere. In Mongolia, just a few outfitters are allowed to host international anglers on rivers that are considered taimen preserves, and regulations are catch-and-release, fly fishing only.
The fishing is about what you’d expect from a 4-foot-long char that feeds aggressively on other fish, ducks and ground squirrels. Dan Bailey, who spent 13 years guiding weeks-long camping float trips with Fish Mongolia, says they are known for savaging large surface flies and violent tail-walking battles on 9-weight fly rods. He said average fish are 20 to 30 inches long and 6 to 15 pounds. Forty inches is a trophy. Once they reach that length, they start putting on shoulders, and a 40-plus-incher might weigh 20 to 40 pounds or a whole lot more. The IGFA all-tackle world record was caught in 2021 on Russia’s Tugur River. It weighed more than 115 pounds.
Alligator Gar – Trinity River, Texas
“There’s very few places in the world where you can go catch 20 to 50 fish a day on lures and they weigh 40 to 150 pounds,” said Capt. Kirk of The Garship Enterprise.
You can do it in Texas, says guide Kirk Kirkland. He’s been on the cutting edge of gar fishing since the early 1990s. Kirkland lays claim to the largest gar ever caught on rod and reel—at 9 feet, 6 inches and 365 pounds—and in 2023 he guided Art Weston to an IGFA all-tackle world record of 283 pounds. The accolades are too numerous to list. Suffice it to say, Kirkland and others are catching and releasing a bunch of giant gar on the Trinity River and its reservoirs.
Until recently—in the last seven years—alligator gar were primarily targeted with cut bait, and Kirkland still has clients who enjoy sinking half-pound chunks of carp on treble hooks. However, he’s figured out how to catch huge numbers of big fish throwing muskie lures and crankbaits.
On Lake Livingston and other reservoirs, gar stack up near the surface in schools of hundreds of fish, 20 to 150 pounds and larger. Hooking them requires a slow retrieve and a crushing hookset with medium-heavy spinning gear, 80-pound braid and steel leaders to stand up to all those alligator teeth.
On the line, Kirkland said a gar might come in easily at first, but it’s chaos once the fish sees the boat. With the drag cranked down tight, expect 10- to 15-minute fights with long runs and leaps. Now do that 30 times in a day. It sounds brutal! Kirkland recently had an angler crack a rib battling a big gar.
Wels Catfish – Ebro River, Spain
If you think culture, history and food are the best reasons to visit Europe, you must not have heard of wels catfish. These behemoths are the heavyweights of the European freshwater scene, and they are about as game as catfish get.
Last summer, fishing content creator Ryan Izquierdo spent five days slinging big lures for wels on Spain’s Rio Ebro. He said it was some of the toughest fishing he’s ever done, and he can’t wait to go back.
With lengths approaching 10 feet and record weights close to 300 pounds, wels are without a doubt some of the world’s largest catfish. But they don’t behave like the bottom-feeders of North America. Sure, they’ll eat live bait or stink bait, but wels also chase down lures, including topwaters. Izquierdo grew excited when asked about battling them on a Penn Fathom 300 with 80-pound braid.
“They’re a crazy, crazy fighting fish. They’ve got several different tricks they’ll pull,” he says. “I actually got pulled out of my belly boat twice into that freezing cold river.”
There are many tactics that work for wels, including trolling, live baiting and a technique called clonking, but Izquierdo likened the style he used to super-sized bass fishing. He spent days pounding banks with 8- to 10-inch curly tails and swimbaits. The biggest thrill was working these lures over matted vegetation.
“I had multiple giant wels come through those weeds, full body out of the water after that lure!” he says.
Arapaima – The Amazon
Most anglers head to the Amazon with dreams of topwater peacock bass and a side dish of the weird exotics South America is known for. There aren’t too many folks with the patience, or backbone, to take on the giant of the jungle: a leviathan air-breather known as arapaima.
Arapaima are native to the vast Amazon basin, where they primarily inhabit still-water lagoons off main river systems. They grow to enormous size, with recorded lengths longer than 10 feet and weights up to 450 pounds. The IGFA all-tackle world record was a huge 339-pound, 8-ounce specimen caught in Ecuador’s Amazon in 2010.
Some of the best sport fishing for arapaima can be found in Brazil, where preserves protect these popular fish by allowing only catch-and-release fishing.
Patience, stealth and heavy tackle are required for anglers pursuing a giant arapaima. They breathe air, which allows them to exist in oxygen-poor backwaters. When they gulp air from the surface every 20 minutes or so, it gives away their presence.
Once you locate them, you can throw 5- to 10-inch baitfish flies or lures at them, but the best bet is to deploy a spread of live and dead baits procured from the area you’re fishing. Then you wait quietly. Arapaima spook easily, and a slammed cooler lid is enough to put one down for hours.
Setting the hook in an arapaima’s boney mouth requires a stiff rod, and 80-pound braid is necessary to stand up to short powerful runs and head-shaking leaps. Clamp down the drag and fight them fast and hard. If they make it into cover, you’re cooked.
