Did anyone tell the Amazon swimmer about the candirú?

In its preview of Slovenian marathon swimmer Martin Strel’s upcoming attempt to swim the entire length of the Amazon river, The International Herald Tribune notes:

Experts say the Amazon is a fertile area for infectious diseases, such as malaria, cholera, yellow fever, river blindness and elephantiasis. Among the predators Strel could face are anaconda snakes, piranha, crocodiles and the Amazon bull shark.

They left out the candirú, the Amazon’s most notorious fish, and the only known vertebrate to parasitize humans. It’s a fish that has no enemies, and is more feared than the piranha. Particularly by men who are foolhardy enough to urinate in the river while skinnydipping. Attracted to the smell, Vandellia cirrhosa will follow the urine’s path, swim into the penis, and, with it’s umbrella-like spines, lodge itself inside the urethra. Removal is grim.

I first heard about this critter and it’s needle-like teeth in Redmond O’Hanlon’s 1989 book, In Trouble Again: A Journey Between the Orinoco and the Amazon, when he described an anti-candiru device he had fashioned before embarking on his journey, essentially a jockstrap with a tea strainer dangling from its end. Once the the litte fish enters, O’Hanlon wrote,

“Nothing can be done. The pain, apparently, is spectacular. You must get to a hospital before your bladder bursts; you must ask a surgeon to cut off your penis.”

The thing is also relentless.

The candiru has a voracious appetite for blood and will parasitize fish, mammals, and humans. One scientist, while holding a candiru, accidently let it enter a small cut on his hand. It could be seen writhing under the skin towards the vein.

[Here’s an account from The Straight Dope of one successful removal; the fish had died, making the procedure easier and slightly less painful.]

The 52-year-old Strel is no stranger to swimming incredible distances. He’s been listed in the Guiness Book of World Records for several long swims of the ‘longest-ever’ variety: the Danube, the Mississippi, and most recently, China’s Yangtze. Setting out on Feb. 1 from Atalaya, Peru, his working plan is to swim up to 90 kilometres per 12 hour day, eventually reaching the mouth of the river in Belem, Brazil, 70 days and 5,430 kms (3,375 miles) later. No word on whether he borrowed any gear from O’Hanlon.

The official journey website is here, where you learn, among other things:

As a young boy, I was beaten a lot by my parents and schoolmasters. This no doubt contributed greatly to my ability to ignore pain and endure…

His personal website is here, while Wikipedia has a good synopsis of his feats to date.

public domain drawing by Robbie N. Cada



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  1. Jean says

    Christ almighty. Thanks for, uh, bringing this to our attention.

    Still, Strel will probably safer swimming the Amazon than this poor guy undergoing surgery in Romania:


  2. borutpeterlin says

    But nobody knows what Strel can do to candirú fish. We should not underestimate Strel under cviček wine influence.

  3. Sheila says

    what does the candiru do to women???

  4. pirano says

    Jean, that link ruined my day. Obviously not as much as that patient’s though. Borut- do you know if there will be any cviček on his supply ship? And Sheila, I know how much you like skinnydipping, so suggest you don’t tempt fate by doing so in the Amazon.

  5. barbar says

    simply terrifying

  6. Sean says

    My neighbor is a doctor and told me about this strange fish. It sounded so strange I had to look it up to verify it was true. This is one nasty fish that makes for a funny story but horrible experience.

  7. mtmannh says

    Indicative, a small fish in South America. This is how my zoology teacher first described it in 1975.

  8. David Irving says

    Wear a condom and a rubber band.

  9. tommy says

    He could wear a condom or two .:P

  10. jerrit says

    wear a condom eh.

  11. nate says

    you can’t urinate in a condom, at least not easily. he made that teastrainer device so i could piss while swimming extraordinary lengths.

  12. Jean Vengua says

    Why can’t people just fricking leave the Amazon to itself and its native inhabitants, who know its ways better? Why do we have to inflate our egos in such ridiculous ways. Instead of wearing a condom and rubber band, or a strainer, better to just not go.

  13. babychaos says

    Ack ack ack… so vile and – knowing nature – so undoubtedly true. Eugh!



  14. ghantha says


  15. Alex says

    I read O’Hanlon’s book, and he made much of the threat of the candiru before he started out. Later, well into his journey, he asked his local guide about the fish and he had never heard of anyone who had the fish go after him. He did say that sometimes when someone was found dead in the water, these fish could be found in pretty much any hole they could get into–nose, ears, mouth, penis. The speculation was that finding the fish lodged in dead bodies might have lead to stories that it will go after you when alive.

  16. pluckymama says

    He’s got a special suite so they don’t swim up his wee wee

  17. flickrhoneys says

    I used to be a candiru… those were the days my friend 😀

  18. justcallmecarley says

    um, excuse me, but gross.

    now i really wished i hadn’t clicked this. lol.


  19. Vengeanceismine says

    Last year I brought back several candiru from Brazil. They breed quite quickly. This next July I will be releasing them into Lake Michigan. Happy swimming!

  20. Glendale Winnipeg says

    Scary stuff !!!

  21. rhk111 says

    Next headline: “Amazon Swimmer Decides To Keep His Private Part & Cancels The Attempt”. 😀

  22. Tim says

    flickrhoneys, that is one of the funniest comments I have read throughout WordPress! 😀 – Tim

  23. mastermistress says

    Ooohh .. I think I saw something about this on the Eco challenge a few years ago … didn’t one of the racers pee in the river, and one swam up that said stream of urine straight into his (whistle whistle)? and one of his fellow racers saw it happen? I could be mistaken .. but I’m sure it this was the program.

  24. Marcos - Brazil says

    Of course he knows about the fish. It has been all over the press in Brazil. He will use a neoprene suit.
    I have to say that the issue has been toooo exagerated, as usual, by the naive American and European press for people who still think that folks live in trees in Amazonia. Millions of people swim in the Amazon rivers everyday and nothing happens…but where are the news in that ?

    This is like saying that you will die if you hike in Arizona because of the rattlesnakes.

  25. subcorpus says

    scary stuff …
    and i live in a country which is 99% water … 1% land …
    and u put this up on ur blog … ???
    hehe …
    also, now i can explain why i need to carry around a condom in my wallet …
    a quick swim … hehe …

  26. rootless says

    I love this post–I read an article about candiru as a child and that cured me of my habit of peeing in recreational waters. I agree with Marcos though.

  27. spatulated says

    those are the scariest creatures alive…

  28. Robert P. says

    An old boss had a boat named after this critter. The boat had been his wife’s and when they divorced he gave up everything but the boat and changed the name from her’s to this fish. In honor of her you might say.

  29. roflmao says

    I agree with Tim

    that comment flickrhoneys was fucking hillarious

  30. MATT says

    hahahahaha! they swim up your stream hahahaahahahahaahaha

  31. peakaction says

    The MONARCH does a much better job of explaining it, IMO. 😉


  32. figment says

    where can I buy these fish?

  33. Tony W. says

    this reminds me of that horrible experience when I peed on an electric fence and found out that electricity also goes up the stream

  34. drmike says


  35. juby says

    Yikes! For real? well, i’ll forward this site to my friends in case they decide to swim the Amazon…heheh

  36. pirano says

    Thanks, Paul.

  37. rush says

    this fish is also known to enter the body through the anus and chew its way through to the urethra in search of urine. mmmmm, urine.

    In addition to the condom, better bring the butt plug, too.

  38. pluckymama says

    That fish was on Grey’s Anatomy last night!!

  39. Buchen Sage says

    “The Man Who Swam The Amazon” lets you live it.

  40. reino says

    haha i was on my hockey team and i didnt belive it.. i googled it and i found it !!

  41. amanda says

    i heard that the fish will eat you alive is that true if so it will make you think twice before u piss in the water

  42. jeremy says

    I heard that the Candiru has to be sucked out as quickly as possible, just like sucking out snake venom.

  43. brad says

    i have a friend that wants to “visit” the amazon see the rainforest i said dont swim! even with these fish what about snakes? too scary for me

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