Well, firstly, sorry.
I will admit it has been a while since I was last on here, but just to make it up to you, today I’ll be talking about an animal more awful than usual. I realise that apologies generally involve things like gifts, or letters, or actual apologies, rather than mentally scarring imagery and links to pictures that are so far beyond ‘Safe For Work’ that you’d probably get fired just for reading the link address out loud, but that’s just the way I roll.
Although, weirdly, it might be that this animal is less horrific than originally thought. I do not know if this makes the apology more or less sincere.
Anyway, today we’ll be talking about a catfish, and if you didn’t know how a catfish could be horrific….well, read on.
Catfishes (properly called Siluriformes) are a large group of fish, originating in the late Jurassic, that incudes around 3000 species. Features of this group include ‘naked’ bodies (i.e. they don’t have any scales, although some do have armour plates, whilst others ‘breath’ through their skin) as well as barbels – whisker like features near the mouth, which are used to feel their way around – which is especially useful as many catfishes live in caves, are nocturnal feeders, or live in muddy, cloudy water (technically called ‘turbid’). Mostly, they live in freshwater, and some species are widely fished – either for sport, or for food (especially in some parts of the United States – so much so that Ronald Reagan declared that June 25 in the USA is ‘National Catfish day’, although sadly he gave no instructions as to how to celebrate it.)
But, why are they on this blog?
Well, it turns out catfishes, like – well, cats – have a dark side. Almost all catfish have spines on their dorsal and pectoral fins, and in some cases these can be covered with mucus and give a harmful – in some cases lethal – sting. The Malapteruridae can give a painful, though not lethal, electric shock. Furthermore, some species can grow to large sizes, and can attack humans. Bagarius yarrelli, for example, can grow up to 2 metres in length, and one is thought to have attacked and killed at least three people in India and Nepal after supposedly – and this is the creepiest part – developing a taste for human flesh after devouring the remains of corpses cremated on the river.
But there is one that makes all of these pale into insignificance, and that is the Candiru fish, aka the Vampire Fish, aka the toothpick fish, aka Vandellia cirrhosa. They are members of a family of catfish called the Trichomycteridae, which also include fish that feed on mucus, carrion and scales, and a number of which live in caves. As the name suggests, Vandellia cirrhosa feeds on blood. Reaching a maximum length of around 17 cm, the fish appears silverly and semi-transparent and, truth be told, doesn’t look that horrific.
But, of course, it is not called the ‘Vampire’ fish for nothing. The fish feeds on the gills of other fish. By biting into the gills with its small, but rather sharp, teeth, it makes an incision into the artery and then just remains in place for no longer than two and a half minutes (and often much less) before letting go, letting the prey’s own blood pressure pump the blood straight into the Candiru. After that, it lets go, engorged with its blood meal that is visible through the fish’s skin.
And then, things get really horrible.
When the first explorers came to the Amazon, they heard, from the local tribes, a truly disturbing story. Men who urinated in the river attracted the Candiru somehow and then the Candiru (which remember, like all catfishes, has spines on its fins) would swim up the stream of urine and lodge itself – well, without being too specific, if you’re a man, imagine the worst place to have a spiny fish lodged in your body.
The fish, of course, would then die and start to rot, somehow making ‘having a spiny blood drinking fish stuck in your penis/other orifice’ even worse. According to legend, the only ‘cure’ was either amputation or, in some cases, a mixture of special herbs that would dissolve the fish, although unless these herbs combined made a strongly caustic cleaner, I can’t see that working. That said, ingesting a strongly caustic substance would probably also kill you, although by that stage that would probably not be a huge disadvantage.
This story has been repeated more or less as gospel truth for around a century, before scientists, in a rare moment of lessening rather than increasing the horror of the natural world, thought that the stories were incredibly exaggerated, if not made up entirely. Firstly, experiments showed that Caniduru were not actually attracted to urea, which was the theory as to why they attracted humans. Secondly, a few moments thought would suggest that it is more or less physically impossible for a fish to try and swim up a stream of urine. (There’s a third objection too, which is even if the fish managed to lodge itself in you, it would certainly die – but this isn’t actually an objection, given that it could be that the fish just made a horrible mistake).
So its all just a horrible urban legend, right?
Well, not quite.
Whilst it certainly isn’t something that happens a lot (some people claim that the fish is the world’s only vertebrate parasite on humans, which is only true if you really stretch the definitions) there is, supposedly, one case of it happening to a man swimming in the water. In 1997, an unnamed patient in Manaus, Amazonia, Brazil was operated on by Doctor Samad, who claimed to have removed a Caniduru from a patient’s urethra and had, thoughtfully, taken pictures, which can be viewed here if you are male and have no intention of sleeping, like, ever again. The patient, in addition to suffering from a-spiny-fish-where-you-really-don’t-want-a-spiny-fishitus, also suffered from catastrophic urine retention and, some reports suggest, a damaged scrotum as the fish had started to chew its way out.
However, some parts of this story, perhaps thankfully, appear not to be true. The recovered specimen had all its spines intact (despite Samad claiming that he had to snip them off to remove the fish) and it also seemed much too big to have – err- fitted in, to put it in the best possible terms. Additionally, the patient claimed that the fish had sum up the stream of urine, whilst the Doctor claimed that the fish was attracted to urea – which, as discussed above, are both probably entirely untrue.
But, despite that, the guy who investigated the case is, apparently, ‘not writing the case off’, and says that although deeply unlikely, it is not impossible that someone immersed in the water could be attacked by the Caniduru.