The Weirdest Catch In River Monsters Season 1

Even though there are a lot of great animal- and nature-centered shows on TV and streaming right now like "Our Planet" or "Man vs. Wild," no other wildlife adventure series lives up to "River Monsters." 

Hosted by professional angler Jeremy Wade, the series follows Wade and his crew as they travel the world searching for numerous species of freshwater and saltwater fish. Although the show is called "River Monsters," Wade goes above and beyond to educate viewers about these animals, demonstrating that they're not as terrifying as they may seem at a glance. His immense respect for and determination to study the fish is palpable through the screen, and it makes for great television.  

Season 1 hooks fans right from the start, with viewers following Wade as he travels far and wide to places like Brazil, Spain, India, and the U.S. in search of fish that you won't be able to find at your local supermarket. Of all the species Wade encounters in the freshman season of this documentary program, his brush with one particular creature in the season's sixth episode, titled "Amazon Flesh Eaters," is sure to send a shiver down your spine. 

In "River Monsters" Season 1, Episode 6, Jeremy Wade encounters the Candirú-Acú, also spelled Candiru Asu, which is a member of the Cetopsis genus of catfishes. With their average length coming in at just under two inches, Candiru Asu can be found in the shallow, slow-moving freshwaters of South America. Using their needle-like teeth, the Candiru Asu feed on the blood and flesh of other fish, and according to "River Monsters," the occasional human being (via Animal Diversity Web). The specimen that Wade captures in the episode sits snugly in the fisherman's hand and looks more like a worm than a fish. On its own, it hardly looks threatening, but these creatures are much more than meets the eye.

The episode follows Wade as he investigates several species of fish with the help of Dr. Lucia Rapp at the National Institute of Amazonian Research. Standing next to a jar of expired Candiru Asu, Dr. Rapp tells Wade about a doctor who recently visited the institute. The visiting physician brought photos of corpses believed to have died due to gunshot wounds. However, when the doctor went to perform an autopsy, the bodies were hollow of organs and blood. Instead, the body cavities were full of Candiru Asu. The suspected bullet holes were entry points made by the fish, who devoured their prey from the inside out. 

The truth about "River Monsters" is that you never know what to expect!