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FAQs on Candiru Cats 

Related Articles: Trichomycterid and Cetopsid Catfishes

Related Catfish FAQs:  Identification, Behavior, Compatibility, Selection, Systems, Feeding, Disease, Reproduction


Blue whale catfish... hlth., sel., FW ray fdg.... dwarf Orcinus...?   3/14/10
My husband and I bought two blue whale catfish,
<Interesting fish. Cetopsis coecutiens, one of a group of Amazonian catfishes known as the Cetopsidae. Rarely kept by aquarists because of their strange appearance, lethargy and strictly nocturnal habits. But apparently not difficult to maintain under aquarium conditions.>
which we have had for a little over two weeks. Yesterday we changed the water and today we noticed some white spots on their body, from what I read on your site, it could be Ich.
<Very likely. All catfish lack scales, and the Cetopsidae also lack the heavy scutes (hardened skin) typical of things like Corydoras and Plecs. So they're very vulnerable to Ick and other external parasites. Treat using the heat/salt method rather than copper.>
We also have a fresh water stingray,
<I hope you won't be keeping these catfish with the Stingray! The Cetopsidae are "flesh biters", ranging from simply biting chunks out of bigger fish in the case of Cetopsis coecutiens through to swimming inside their gill chambers and feeding on blood, as in the case of the infamous Candiru. Without exception, Cetopsis are either kept singly (they're not happy that way) or in groups of their own kind (much better). But never, ever with other fish, except possibly larger, armoured catfish like big Doradidae. Make sure you feed these catfish a healthy diet, i.e., not goldfish or minnows. Earthworms are a favourite food, and you can augment these with fresh and wet-frozen foods of all sorts: tilapia fillet, squid, mussels, prawns, etc. The usual warning about minimising foods that contain thiaminase apply here, so while mussels and prawns are good in some ways, they shouldn't be used too often. Be sure to read Marco's excellent piece of thiaminase and aquarium fish for more on this topic.
Settled specimens may take carnivore pellets.>
and I want to make sure that I know what to feed him, he is about an inch in diameter.
<Feeding what, the Stingray? At an inch in diameter Stingrays are VERY easy to kill, and I'm surprised you were sold one this small. It's very unusual for (good) retailers to sell them that small. In any case, at that size they mostly feed on live insect larvae including bloodworms and mosquito larvae; wet-frozen may be take as well, but I'd start off with live food until the little chap has put on some weight.>
Also, this may sound strange, but is there such thing as freshwater or saltwater mini killer whales?
<Yes and no. Obviously no, there are no "mini" killer whales as such. But there are some small, pack-hunting fish. Of the species in the trade, Exodon paradoxus is the one most often kept by aquarists. If kept in large groups (like 20!) the pack works properly and they're great fun to watch when you throw a bit of fish fillet or seafood into the tank.
Unfortunately, too many people try to keep this species in smaller groups, and even in groups of 10 they have a tendency to turn on one another, and you end up with just one specimen.>
<Cheers, Neale.>
Re: re: Blue whale catfish   3/14/10
Where I bought them from, they were in the same tank together and the catfish don't seem to be bothering the little stingray.
<So far. But what these catfish do in the wild, apparently, is swim about at night and bite chunks from anything too big to be swallowed whole. See how they lack long whiskers? That's so there's nothing to get in the way of that big mouth when it's pressed against its target. These aren't "scavengers" that use their whiskers to find worms and such in the mud!
Your species is a large (25 cm/10 inch) predator that cannot be kept in multi-species tanks.>
I also looked up the "mini killer whale", and I didn't find much on them.
Do they have blow holes and or use them?
<I have no idea what you're asking here. There are no mini killer whales.
You're talking about the big black-and-white dolphins, right? As for freshwater fish species, there are things called Baby Whales, and this is a nickname used in the trade for small, schooling Mormyrids, in particular Pollimyrus isidori. Mormyrids are difficult fish to keep, and I'd strongly recommend you read up on their very specific needs before buying any. They are difficult to mix with other fish, and because they are sociable electric fish, you have to keep a certain number or else their communication goes haywire and they bully each other. Six is a good number
to start with.>
Or do the catfish? We were waiting for a mini killer whale, that the pet store said that they could get and have had one before, and she also said that they used there blow holes.
<She's talking nonsense. There are no cetaceans sold as pets via aquarium shops. Whatever she's talking about, it's not a "killer whale". I haven't a clue what she actually means. If you can get a Latin name, then I can help.
But otherwise...>
Any way, when the catfish came in, she told us that the whales were in, and she said that they use their blow holes, I know I asked above, but is that true?
<No fish has a blowhole. A blowhole is a nostril used to pass air to the lungs. Since fish don't have lungs and breather via their gills anyway, they don't need a blowhole.>
I feel like this pet store has done nothing but lie us.
<"Lie" is a strong word, but ignorance is VERY common in some parts of the hobby. The solution is simple. Find out about the fish first, then get some information from a trustworthy aquarium book. Failing that, e-mail us here,
since we write books and magazine articles, and we're about as reliable a source of information as you're going to get. If you don't have the Latin name for the fish, and the common name the store clerk offers doesn't match
anything you can find in a book, then take a photo and send that. But whatever you do, read before you buy.>
I also bought what I was told to be a freshwater dragon fish.
<A brackish water goby, Gobioides broussonnetii. Actually very easy to keep in a brackish water system. But yes, its lifespan in freshwater is minimal, and it does need a good, varied diet based on stuff other than mere flake.>
Unfortunately it died three or four days later. I believe that this pet store doesn't care about their animals, but more about the money. I can't believe that any person couldn't give a care about the animals that they are selling.
<Caveat emptor, I'm afraid. If a store really does go out of its way to be disingenuous, you might want to ask to speak to the manager and explain your concerns. If that doesn't help, write to your city or county retail licensing office. Pet shops are regulated to some degree, and they have to provide a certain degree of care to their animals. If they're failing in that regard, then the city or county will inspect them, talk with them about how to improve, and if necessary remove their license.>
<Cheers, Neale.>

Trichomycterid pix   4/12/06 Jean Claude ADROVER            12/04 Naturalist 7 rue BERGHEAUD 7 31000 TOULOUSE      FRANCE                       Dr. Robert FENNER, Please tell me if exist a figure of these TRICHOMYCTERIDAE I don't find :G MIUROGLANIS and SCHULTZICHTHYS. If exist please send me a copy. Thank you in advance. Sincerely. <Mmm, have you checked on Fishbase.org? Google images? Likely a visit/bibliographic search at a large college library will show whether there are graphics for these (possibly just line drawings or such). I do not have photos of these. Robare Fenner> Candiru requirements in captivity  8/30/05 I was wondering what the requirements are for the requirements are for keeping Candiru (Vandellia cirrhosa or Ochmacanthus orinoco) in captivity successfully. what would you feed them, compatibility, husbandry, and can more than more Candiru be kept in the same tank? I would like to possibly keep a couple of them in captivity. CJ <Mmm, for scientific purposes these fishes have been kept for study... thus far (as far as I'm aware natch), trying to feed them "parts" of other fish life has failed... and thus they have been kept with fishes that they feed upon live... Not compatible with other fishes, not able to be kept in mix-species settings. There may be more... by "doing" a search of scientific literature. Bob Fenner>

You should never pee in the Amazon River... (OUCH!!) Dear Cecil: In the past I have heard tell that you should never pee in the Amazon River lest a certain fish swim upstream into your penis and lock its fins in place in your urethra. Of course I always dismissed this as a tall tale spread by the natives to scare tourists. However, I read recently in the newspaper about the Candiru fish, which allegedly does just this. Please gimme the straight poop. --Chase Kimball, via the Internet <Tis so. Bob Fenner> Dear Chase: Can't blame you for your skepticism--this is one of those stories you want desperately not to believe. Here's a description from a 1973 article in Urology by John Herman: One of the strangest [stories from the Amazon concerned] a fish that was urinophilic and could swim up the urethra or into the vagina of the unwary native who urinated while bathing in the Amazon. It was said that this fish, known as Candiru [in Brazil; as carnero in Spanish-speaking countries], was long, thin, and capable of forcing its way into the body's passageways following the trail of urine. Once inside it would eat away the mucous membranes and tissues until hemorrhage would kill it or the host. It was also said that even if one caught the fish by the tail, once in the urethra it could not be pulled out because it would spread itself like an umbrella. Indeed, rumors had it that penectomy was preferred to the misery and pain associated with leaving the fish in the urethra! Yeah, I know. I crossed my legs too. Herman's article is titled, "Candiru: Urinophilic Catfish, Its Gift to Urology," which doesn't seem like the world's most sensitive take on the subject. However, the author refers not to the financial opportunities for urologists but to an anti-Candiru folk remedy useful in treating bladder and kidney problems. More on this below. Are stories about the Candiru true? Although many mentions of the Candiru can be found on-line and in popular books and magazines, scientific accounts of the fish and its unfortunate habits are old and suspiciously few. Most of what we know comes from the 1930 book The Candiru by Dr. Eugene W. Gudger of the American Museum of Natural History, plus a couple additional articles published in the '40s. All sources insist that the incredible story is true, but for evidence they rely mostly on vague second- or third hand reports from missionaries, doctors, natives, and the like. Even the doctors' accounts tend to lack persuasive detail, although one article (Lins, Journal of Urology, 1945) claims a U.S. navy surgeon named Charles Ammerman operated on three Candiru victims, in one case slicing into the bladder to extract the fish. Whatever the truth may be, there's little doubt that the Candiru, formally known as Vandellia cirrhosa, is capable of attacking humans in the manner described. A type of catfish, the Candiru is known to lodge in the gill cavities of larger fish, where it subsists by sucking the blood of its host. Specimens average three inches in length and a quarter inch in diameter. A fast, powerful swimmer, the fish is smooth and slimy, with sharp teeth and backward-pointing spines on its gill covers that make it virtually impossible to remove. Still, it's difficult to imagine how even the most agile of fishes could squirm into someone's penis during a brief dip in the water, and in fact one account says women are much more likely to be Candiru victims due to the greater dimensions of the female aperture. One suggestive bit of evidence is a folk remedy used by Amazon natives, namely the green fruit of the jaguar tree, Genipa americana L. The juice of this fruit is brewed into a tea and drunk hot, supposedly causing the skeleton of the fish to dissolve and resulting in its expulsion from the victim within a couple hours. Early observers scoffed at the effectiveness of this concoction, but in 1945 urologist Eugenio Lins reported that a synthetic version of the brew had dissolved bladder "incrustations" in a dozen patients and suggested that it might do the same for kidney stones. Some elements of the Candiru legend are clearly exaggerated. There are no confirmed reports of deaths or penectomies--several cases of the latter are thought to have run afoul of piranha. It's uncertain whether the Candiru is actually "urinophilic," and as far as I know, no one seriously maintains that it can swim out of the water and up a urine stream. Just the same, next time my yacht cruises down the Amazon, I ain't peeing over the side. One last thing. Lest you think the Candiru is all bad news, one visionary has proposed them, apparently seriously, as a key prong in a "fish-based security system" for the South Pacific--see www.spc.org.nc/coastfish/Reports/misc/wp99/candiru.htm. You dig a moat around your house, see, and stock it with Candiru, piranha, and electric eels. "Should the housebreaker fortuitously not be attacked by the electric eels or the piranha then there is a good chance that he will suffer the invasive penetration of the Candiru into the urethra." Is that brilliant or what? OK, you might lose a few pets or small children, too, but at least your silverware will be safe.

Cetopsid whale catfish Hey, Bob <Hello Antoine>    Look what I peeped at the LFS... the little bastard came charging at me when it saw that I had a hangnail. (three pics attached... I think <G>... got bumped from your Hotmail) <What a neat fish>    A ferocity the likes of which I have not seen since the furry white bunny rabbit of Death. Yep... I had to bust out the holy hand grenade to stop it <G>. <Run away! Run away!>    In truth... the poor bugger seemed to be under considerable duress... paced faster than an ADDH child on a sugar rush. <No Ritalin for him, please!>   Crop or delete as you see fit :) <Hotay, thanks. Bob F>

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