The Essequibo River is the largest river in Guyana, South America, and it contains more than 300 known species. Despite this, parts of the river remain poorly known. In this clip filmed for the BBC’s Expedition Guyana, Steve Backshall and Dr Phil Willink set off on the first fish survey of the upper part of the river.
- "Capable of striking fear into the heart of divers everywhere, it's as dangerous as it is beautiful..." 10 deadliest, most dangerous fish on the planet
- "He described animals swallowing 94°C water and cooking from the inside out, boiled alive, before being able to escape." 10 deadliest rivers in the world
With the help of a local fisherman, they make an impressive catch – the redtail catfish (Phractocephalus hemioliopterus), known in Guyana as the banana catfish.
“You can tell it’s called a banana catfish because it’s yellow on the belly like a banana,” remarks Willink.
But more interesting still are the parasites attached to it – vampire catfish (Vandellia cirrhosa), or candiru.
“Apparently, if you stand in the water in these areas and you go to the toilet, it will swim up the stream of urine and right inside you and launch inside you using two backward-facing spines,” warns Backshall.
He’s repeating a piece of Amazonian folklore so enduring that biologists spent decades investigating it. Notable research by marine biologist Stephen Spotte casts serious doubt on the claim: candiru appear to locate prey by sight rather than through urine, and the physics of swimming upstream against a urine stream make the scenario extremely unlikely.
That doesn’t mean one should run the risk of going to the toilet in the river anyway, just to be safe.
Night hunters
As night falls, the explorers want to know what rules the river under the cover of darkness. And there it is: a sabre-toothed characin, also known as the sabre-toothed tetra (Hydrolycus scomberoides).
“It’s the nearest-looking thing to an actual monster I’ve ever seen. It certainly deserves its sabre-tooth name. That is incredible,” says Backshall.
Their impressive, curved teeth are so long, they need special sockets in their skull to accommodate them – otherwise, they would pierce the fish’s brain.
“This is a top predator. They’re extremely fast, they swim around and they come up below fish and just spear them and kill them instantly,” says Willink.
Backshall carefully releases the fish, making sure not to get caught in the jaws of this terrifying predator.
“Now we’re seeing the night shift – the big catfish, the sabretooths. By day, the piranhas rule the rivers. You’re never safe,” concludes Willink.
- Pound for pound, this little fish has the most savage, brutal bite ever measured – way stronger than a great white
- 6 of the world's most venomous fish, from the deadly stonefish to the beautiful and dangerous lionfish
Top image: aerial view of Essequibo River in Guyana. Credit: espiegle/Getty Images
