In his quest to save the world s big fish, aquatic ecologist Zeb Hogan has wrangled what s currently the world s biggest known freshwater species, the Mekong Giant Catfish. But is it really the biggest? We ll join Zeb as he travels the globe, seeking out the leading contenders in a quest to better understand them as he fights to protect them. It s a heart-pounding adventure as Zeb heads into some remote areas and wild waters, braving piranha, crocodiles, and a host of other hazards. Along the way, he ll explore the local haunts and find out how these massive creatures figure into the local culture-the lore surrounding them, their role in the ecosystem, awesome physical features, strange behavior, and the surprising cycles of life that transform a thumb-sized larvae into a 400-pound beast.

Join National Geographic Explorer Zeb Hogan on a quest to save some of the biggest freshwater fish in the world. Well track the elusive freshwater stingray, believed to be only a legend in northern Cambodia until Hogan came face to face with one. Need proof? See exclusive, never before seen underwater images of these giant freshwater stingrays.