Researcher Zeb Hogan travels to Cambodia to find and study the little-known giant stingray.

Follow Dr. Zeb Hogan on his journey to find the largest freshwater fish in Australia: the freshwater sawfish.

Follow Zeb Hogan as he goes in search of the biggest and oldest of North America's river monsters: the White Sturgeon.

Follow Dr Zeb Hogan on his quest to find what could be the world's largest and most deadly freshwater fish: the giant freshwater stingray.

Aquatic ecologist Dr. Zeb Hogan teams up with kayaking experts to discover what monster fish are lurking beneath the surface in Rio Roosevelt.

They are carp from Asia which can jump 10 feet in the air at the sound of a boat motor, turning a day on the water into a boxing match.

We don't have an overview translated in English. Help us expand our database by adding one.

We don't have an overview translated in English. Help us expand our database by adding one.

We don't have an overview translated in English. Help us expand our database by adding one.

We don't have an overview translated in English. Help us expand our database by adding one.

Dr Zeb Hogan travels to the American Midwest in search of the paddlefish, one of the largest, oldest and most bizarre -looking freshwater fish on the planet.

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Giant freshwater fish are studied at Khone Falls on the Mekong River in Laos.

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Zeb Hogan travels to Spain in search of the invasive Wels catfish -- a monster fish capable of growing more than 8 feet long, eating birds, cats, and, as some legends claim -- even humans! The voracious predator is not native to the region, and biologists fear it could be destroying the local ecosystem.

Flying fish from Asia are invading America's waterways and turning innocent boating trips into boxing matches as fish "knock out" anglers. National Geographic Explorer Zeb Hogan heads to the Illinois River, one of the areas where their population is thickest, to see what can be done to stop them ... and the answer could be as simple as your dinner plate.

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Dr Zeb Hogan searches the southern United States for the rapidly disappearing alligator gar.

Zeb travels Thailand in search of giant fish; freshwater protected areas.

Zeb Hogan is on a mission to find the giants of the sea.

Zeb travels to Spain for the wels catfish, a vicious predator that destroys local ecosystems.

Zeb Hogan attempts to fathom the uncontrolled spread of flying Asian carp in America's waterways.

Amazonian expedition to assess the impact of humanity on the area's fish population.

Zeb faces the crocodiles and goes in search of Africa's biggest freshwater fish: the Nile perch.

Aquatic ecologist Dr Zeb Hogan goes in search of the paddlefish.

Aquatic ecologist Zeb Hogan and fellow scientists search for Nile perch.

Each year in the Australian outback, the dry season leaves five top predators- giant stingrays, sawfish, bull sharks, and freshwater and saltwater crocodiles- stranded in waterholes with limited food supplies.

The giant eel is a massive, flesh-eating, wall-climbing, air-absorbing, snakelike fish that can attack like a crocodile and live upwards of 100 years. So, of course, Zeb goes in search of two of the largest species.

The Murray cod can grow up to 6 feet long and weigh more than 250 pounds, and is rumored to eat everything from birds to snakes to possums even its own kind. But humans have been encroaching on the cod's river system, and now these enormous fish are rarely seen in the wild.

Kamchatka, Russia, is one of the wildest and most remote locations on earth and is home to the largest salmon population on the planet but why? Zeb travels to the Far East to explore this salmon paradise.

A mammoth catfish that has allegedly stalked, attacked and killed people can be found in the Indian Himalayas. Dr. Zeb Hogan investigates reports of the goonch.

One of the oldest and most bizarre-looking freshwater fish on the planet can be found in the American Midwest. That's where Dr. Zeb Hogan travels to find the paddlefish.

Dr. Zeb Hogan travels to one of the world's largest waterfalls in Laos, where each year millions of fish climb the falls to spawn.

Lured by stories of catfish the size of Volkswagens, Zeb Hogan is on a mission to find out if the legendary giant catfish of the South really exist.

Armies of salmon surge through Alaska's icy waters during mating season, but only one catches the eye of Zeb Hogan the elusive king salmon.

The Pacific Northwest is known for things that are BIG giant redwoods, sweeping coastlines and massive runs of salmon.

Zeb Hogan is on the hunt for a goldfish the size of a cow! Giant carp can grow up to weigh 600 pounds and measure 10 feet long, but the trouble with finding these monster fish is they only live in three of Southeast Asia's rivers

It's a voracious predatory catfish that prowls the rivers of Southeast Asia.

Zeb is on a quest to catch a river shark to determine the truth behind their deadly reputation.

Thailand's giant stingrays and the whip rays of Australia can grow up to 16 feet and 1,300 lbs.

Wolf fish, known locally as haimara, can reach a metre in length and is said to hunt humans.

There's a freshwater fish with a shock five times more powerful than a US wall socket.

The Thai snakehead is said to be able to move on land, and has apparently spread to US waters.

In Nicaragua, Zeb faces his most difficult battle hunting for one of the biggest monsters.

Some shark species can survive in freshwater as well as salt.

Fish biologist Zeb Hogan is searching for one of the freakiest fish in the world. Vampire fish, known locally as payara, weigh up to 40 pounds, hunt like great white sharks and have terrifying 6-inch fangs.

Join Zeb Hogan as he explores the maze-like river systems of Argentina on a quest to catch a colossal 400-pound short-tailed river ray, the largest freshwater stingray found in South America, and uncover the surprising sting hiding in its tail!

Join Zeb Hogan as he heads to southern France to try to catch a mammoth-sized 650 lb. Wels catfish and witness one of the most bizarre feeding behaviors he's ever heard of.

Zeb explores Florida's deep-water reefs on a mission to catch a seven-foot goliath grouper.

Zeb Hogan searches for a 400-pound short-tailed river ray in South America.

Zeb Hogan returns to Thailand to find the biggest monster fish on Earth.

Some adaptations can yield freakish results due to all of the unique environments of the oceans.

Zeb heads to the ancient French town of Albi in search of the wels catfish.

Zeb Hogan embarks on a six-continent journey as he seeks out the world's biggest and rarest fish.

Zeb Hogan searches for a ferocious fish with fangs and a ray with a hidden weapon.

The Salween River Basin has an extreme diversity of animals, and is home to some 50 fish species found nowhere else on Earth.

Zeb teams up with renowned shark scientist, Dr. Tristan Guttridge, who has been conducting research on the annual migration of Great Hammerheads for years.

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