Tom Rowland Podcast Episode 741 is my conversation with Zeb Hogan, the fish biologist, National Geographic Monster Fish host, and author of Chasing Giants: In Search of the World's Largest Freshwater Fish. Zeb's book opens with a 646-pound Mekong giant catfish caught in Northern Thailand in 2005, a fish that launched a question he thought would have a simple answer: what is the world's largest freshwater fish? It turned into a years-long global quest, and we get into the whole thing.
Listen now: Apple Podcasts · Spotify · YouTube · Press play in the player above to watch.
Zeb Hogan is a fish biologist, host of National Geographic's Monster Fish, and the author of Chasing Giants: In Search of the World's Largest Freshwater Fish. His career centers on studying and protecting the planet's largest freshwater fish, work that grew out of his PhD research on the Mekong River and a 646-pound giant catfish caught in Northern Thailand in 2005.
Chasing Giants: In Search of the World's Largest Freshwater Fish is Zeb Hogan's account of his quest to answer a deceptively simple question: which fish is the world's largest in freshwater? The book begins with a 646-pound Mekong giant catfish and follows Zeb around the world as he separates real giants from exaggerated claims and confronts the conservation challenges these fish face.
The 646-pound Mekong giant catfish was caught in Northern Thailand in 2005 while Zeb Hogan was working with local fishermen during his PhD research. The fish was ultimately killed and sold for food, and witnessing it prompted Zeb to ask what the world's largest freshwater fish actually is, the question that became Chasing Giants.
Zeb Hogan found the question far more complicated than expected. There are many competing claims, the definition of a freshwater fish matters because species like beluga sturgeon and bull sharks move between salt and fresh water, and fishermen often exaggerate. To find the truth, he focused on exclusively freshwater species and traveled to see the fish himself rather than relying on stories.
Tom Rowland Podcast Episode 741 with Zeb Hogan is available on Apple Podcasts, Spotify, YouTube, and iHeartRadio. The video version is embedded at the top of this page.
I have watched Zeb's Monster Fish work for years, so getting him on around his book Chasing Giants was a real treat. What I love about Zeb's quest is how a simple-sounding question — which freshwater fish is the biggest? — turned out to be wildly complicated, full of exaggerated claims, tall tales, and genuine giants. He had to travel the world and see the fish himself to separate fact from legend. As an angler who loves big fish, I wanted him to walk me through the whole search.
Press play in the YouTube player at the top of this page to hear the full story.
Chasing Giants opens with the catch of a 646-pound Mekong giant catfish in Northern Thailand in 2005. Zeb was there, working with local fishermen as part of his PhD work, when the fish came in — and was ultimately killed and sold for food. That moment prompted the question that became the book: what is the world's largest freshwater fish? Listen to how that catch set everything in motion.
Zeb thought he could just look it up. Instead he found a tangle of competing claims, from giant beluga sturgeon in Europe and Russia to enormous catfish and freshwater stingrays. He had to decide on a definition — he focused on fish that live exclusively in freshwater, ruling out species like sturgeon and bull sharks that move between salt and fresh. The definitional problem alone is fascinating. Watch the YouTube player above for how he sorted it out.
Fishermen exaggerate — Zeb is the first to say it. He found endless claims of record fish, plus urban myths about catfish swallowing people. To get the truth he had to travel to each location, talk with local scientists and fishermen, and get out on the rivers to see the fish with his own eyes. That fieldwork is the spine of Chasing Giants. Listen to how he verified what was real.
Zeb's work is not just record-chasing. The giant Mekong catfish that opened the book was killed and sold, and his quest runs straight into the fragility of the world's biggest freshwater species and the rivers they depend on. The conservation thread is what gives the adventure its weight. Press play in the YouTube player above to hear what he learned about protecting these fish.
Listen to the full conversation: Apple Podcasts · Spotify · or watch in the YouTube player at the top of this page.
The day after talking to Zeb, what stuck with me was how a simple question can open into a lifetime of work. He set out to name the biggest freshwater fish and ended up documenting some of the most threatened animals on the planet.
Chasing Giants is the rare book that scratches the angler's itch for monster fish and makes you care about the rivers that produce them. Zeb has spent his career where curiosity and conservation meet, and it shows.
Press play in the player above, or grab Episode 741 on Apple Podcasts or Spotify.
The Tom Rowland Podcast brings you long-form conversations with the most accomplished anglers, hunters, conservationists, and outdoor professionals in the game. Listen to every full-length Tom Rowland Podcast interview.
Zeb Hogan · Chasing Giants (book) · National Geographic Monster Fish · Mekong giant catfish · Northern Thailand · beluga sturgeon · freshwater stingrays
Zeb Hogan is a fish biologist, National Geographic Monster Fish host, and the author of Chasing Giants: In Search of the World's Largest Freshwater Fish. His work began in earnest around a 646-pound Mekong giant catfish caught in Northern Thailand in 2005 during his PhD research, which launched a global search to identify and understand the planet's largest freshwater fish. Traveling the world to study giants such as catfish, stingrays, and sturgeon, he has become a leading voice for the conservation of megafish and the rivers they depend on.
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