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FAQs on  Corydoras Cat Social Disease

FAQs on: Corydoras Catfish Health 1, Cory Disease 2, Cory Disease 3, Cory Disease 4
FAQs on Corydoras Catfish Disease by Category
: Environmental, Nutritional (e.g. HLLE), Infectious (Virus, Bacterial, Fungal), Parasitic (Ich, Velvet...), Genetic, Treatments,
Related Articles: Callichthyid CatfishesSummer loving: cats in the garden, kittens in the kitchen by Neale Monks,

FAQs on: Corydoras Catfish 1,
Corydoras Catfish Identification, Corydoras Catfish Behavior, Corydoras Catfish Compatibility, Corydoras Catfish Stocking/Selection, Corydoras Catfish Systems, Corydoras Catfish Feeding, Corydoras Catfish Reproduction,
FAQs on: Panda Corydoras, Pygmy Corydoras spp.,

FAQs on:
Callichthyids 1, Callichthyids 2,
FAQs on: Callichthyid Identification, Callichthyid Behavior, Callichthyid Compatibility, Callichthyid Selection, Callichthyid Systems, Callichthyid Feeding, Callichthyid Disease, Callichthyid Reproduction, Catfish: Identification, Behavior, Compatibility, Selection, Systems, Feeding, Disease, Reproduction

Most Corydoras are VERY social species... live in large shoals of their own species.

And many fishes will pick on Corydoras, bite out their eyes; chew on their fins. Even, often to their demise (cichlids esp.) swallow them.

Quick question about Corydoras catfish 5/11/10
<Hello Judy,>
I was just wondering if it is harmful to keep just one Corydoras catfish?
<"Harmful" is a difficult word to use here. Yes, these are schooling catfish, and if kept singly the loner will be stressed and therefore more likely to get sick.>
I have a 10 gallon tank with 6 Neons and one Corydoras. Is one alone stressed out since they are so social??
<Yes. Get four more of the same species!>
Thank you!
<Cheers, Neale.>

Corydoras dying  - 10/22/2012
Hello. I've been having this fairly recent problem with what started as a school of 8 mixed Corydoras (two skunks, two julli, two elegans, two false bandit).
Around July I lost a skunk Cory, a week later the other skunk died. I wasn't sure if that was just a fluke.
Then about a month later it was a julli, and now just a week ago I noticed one of the false bandits surfacing a lot, and resting in my floating plants, emaciated and not looking very good.
I noticed his fins were torn,
<What other livestock here?>

 so I set up a large clean container, put an airstone in, and put him and the other false bandit (also torn fins, no barbels) in there, treating with MelaFix and PimaFix combined,
<Worthless; search WWM re>

 at least for the sake of the second one. The very sick one was laying on his side at first, and the next day I checked and he was sitting upright.
On the third day he died, but I continued treatment for a week for the second one, hoping to help with torn fins. After I saw some regrowth I eased him back into the 55. I noticed he was breathing rather rapidly, but I figured it was just from the whole acclimating deal. Yesterday he was active, until he swam up and rested in the same spot of plants the other one did. Today I found him dead by the filter. That was the only one who didn't show the usual symptoms, besides not really eating.
Symptoms include lethargy (even for a Cory), no interest in food, and eventually they get skinny and die. Not all of them have had torn fins. The tank was started last December and is a 55 gallon stocked with the 3 remaining Corydoras (2 elegans, 1 julli) 8 neon Rainbowfish, 10 harlequin Rasboras, 6 Madagascar Rainbowfish, 5 zebra danios, 1 Bristlenose plecostomus,
<This Ancistrus may be the root of trouble here>

3 banded mountain loaches, 5 Kuhli loaches, 1 survivor Oto, 1 dwarf gourami, 5 gardneri killifish, 3 flower shrimp and 1 Rhinogobius wui/duospilus that I'm trying to move to his own 10 gallon. Ammonia and nitrites are at 0ppm, nitrates under 20ppm.. The pH sometimes fluctuates a little during water changes because we have very hard city water, and the driftwood in the tank ends up buffering that to around 7. Temperature is at a consistent 75 degrees Fahrenheit. The tank is planted, with dirt capped by gravel. (I know gravel's a no-no for them, but I wasn't aware at the time of buying them of how detrimental it could become) I do weekly 15-20% water changes.
At first I suspected the banded mountain loaches were hogging the food, because they're quite voracious eaters, squabbling with each other and guarding their food, but I'm making sure the cories are getting some I feed algae wafers, shrimp pellets, frozen bloodworms, frozen brine shrimp, and frozen glassworms. When I have the worms out, the elegant cories will eat from my fingers, so I feel better about that. Not sure of the best way to treat my remaining 3, because I'm fairly positive it's only a matter of time. I'm thinking parasites at this point, but what would you suggest using or trying?
<Removing the Loricariid or the Callichthyids to elsewhere... separating them. Someone, something is beating on them...>
 But then if it were parasites, wouldn't my other fish be showing symptoms?
<Likely so; yes>
 Everybody else has been seemingly healthy. Even the cories, though they aren't terribly active, have little full bellies until their last week.
Advice is greatly appreciated.
<I have experienced such troubles myself twixt these catfishes... Some "Plecos" will "ride" other fishes... cause them health issues by sucking off their body slime... Bob Fenner>
Re: Corydoras dying     10/23/12

I don't really think it's the plecostomus,  because he tends to stay on his driftwood,
<Not during the night; this is when they're most active>
 but I don't think it'd hurt to move them and see what happens.
Wouldn't there be some kind of visible evidence on the fish if that was the case?
<Mmm, yes... the torn fins you mention, a lack of body slime and what it portends... infection, death>
 I wondered if Corydoras have some sort of specialized disease, like dwarf gouramis can get "dwarf gourami disease", or how neon tetras can get "neon tetra disease". But I haven't heard of it. Just a thought.
<Corydoras do die more easily given some types of stress, conditions, but no specific pathogens as far as I'm aware>
Do you think I should move the three into my recently cycled (started on Oct 2. It cycled quickly.), heavily planted ten gallon and see how that goes?
<Yes... with a good deal of the current water, perhaps a bit of "mulm" siphoned from the older tank's gravel>
 Right now it just has one Danio. She's my 'ammonia source' for now.
There IS small gravel, for substrate, but oh, well. Wasn't planning on more cories, because I've just had the *best* luck with them.
If it so happens that there's an internal parasite involved, what would you treat them with if it comes to that?
<... would depend on its diagnosis, identification. I myself would not simply "blast treat" w/ anti-Protozoals, Anthelminthics et al. w/o knowing what I was treating. BobF>

Cory Help... sel., hlth. 2/1/08 Hi! I have recently bought one albino Cory for my 20 gallon aquarium. Along side the Cory in the tank are 3 marble mollies, a balloon molly, 2 white fin tetras, and a zebra tetra. <No such thing as a "zebra tetra" -- do you mean a Zebra Danio? Small minnow with longitudinal gold and purple stripes.> My problem is my Cory is acting extremely weird. He swims up and down radically and never stays in one spot too long. Sometimes he just frantically swims around and around in the aquarium. I feed him using fish flakes and sinking pellets. But it seems as though he doesn't eat this food. I have had him for 4 days now. Could he be acting strange due to the presence of the other fish? Or is there something else that could be a contributing factor to this? <He's lonely, scared, and miserable -- and likely wondering why he was bought by someone who doesn't research their fish first, usually an omen of doom for unfortunate fish. Corydoras are *schooling* fish, and have to be kept in groups. Four is the minimum really, and you need six or more to see them at their best. So go to your retailer and buy some more. Albino Corydoras are usually Corydoras paleatus, so you can mix them with regular Corydoras paleatus (known as "peppered Corydoras" in the trade).> Sincerely, Michael <Cheers, Neale.> <<Well done Neale. RMF>>

Bronze Cory Help!!! 10/17/09
First off I want to say that your site has been a great deal of help. As a first time fish owner I have used your site as a resource in having a happy and thriving tank.
<Thanks for the kind words.>
I have had my 35 gallon fresh water tank since end of April. I followed the beginner guidelines in circulating the tank before I put in any fish. Right now I have four Rosey barbs, a rainbow shark, Pleco, and three bronze Corys and so far haven't had any problems until today.
<Sounds an interesting mix. While the Rosy Barbs and the Corydoras both appreciate somewhat cool water, Rosy Barbs can be "fin nippers" and work best in large groups (six or more specimens, a mix of males and females) so they busy themselves chasing one another around rather than other fish.
Rainbow Sharks can be feisty, and the Plec will get far too large for this aquarium. So you will have some problems to fix before too long.>
Icky, one of my Corys went missing this week. I searched the tank and he was no where to be found. Today, we did a 60% water change and put in some Columbian drift wood. After picking up a rock that was, until today, thought to be a safe tank decoration - out zooms icky the Cory catfish looking pretty rough. For the first couple of minutes of being free from his confines he was laying on his side. After a little more time passed he's sitting in his natural stationary, but upright, position. It looks as though the barbs made a meal of a few of his fins, and he has several spots that have been worn from trying to wiggle out from beneath the rock.
<Yes: Rosy Barbs will indeed nip at fish. For whatever reason, Corydoras are "sitting ducks" where nippy fish are concerned. I find that whereas Plecs and Synodontis keep out of the way, every time I've kept Corydoras with, say, Puffers or Ameca splendens, they've had their dorsal fins nipped.>
It looks as though he's on the track of pulling through, but you never know with fish. Do you have any advice on how to treat this situation?
<Beyond clean water, I'd not do anything else apart from separate them.
Corydoras fins heal very quickly, and like many catfish, they're likely to react badly to copper or formalin, so I wouldn't use either unless I absolutely had to. So move the school of Corydoras to an aquarium of their own, something 20 gallons upwards, and let them settle down and be happy.
Rosy Barbs sound like a poor choice of tankmate here. You might even get rid of the Rosy Barbs; when all is said and done, they're big fish (up to 15 cm/6 inches) not suited to 35 gallon tanks.>
I'm worried that icky may not make it.
<Cheers, Neale.>
Re: Bronze Cory Help!!! 10/17/09

The Rosey barbs and the Corys get along, they really mind to themselves or get chased every once in a while by the shark. Luckily the only issue we have had with the barbs is that they chase and nip at each other.
<What they do. If kept in large groups, six or more, and ideally more females (yellow-green) than males (pink) then they tend to settle down. In the right tank, a spacious subtropical system, they're superb fish.>
We are fairly certain that the reason why icky the Cory cat has had a good amount of his fins nipped off is because he was literally stuck under the rock but the barbs could still get to him.
<Whether he got stuck under the rock, or was hiding to avoid being nipped, is difficult to answer. Both explanations are possibilities.>
Right now the rough looking Cory looks as if he is acting normal, but he really looks rather rough.
<Indeed. Usually, Corydoras heal very well. The common species like Bronze and Peppered Corydoras have become so popular precisely because they are so durable.>
We know of the issue with the Pleco out growing our tank. We have a home for him when he gets big enough in a 300 gallon brackish cichlid tank at a restaurant that we frequent.
<A home perhaps, but a bad one. Plecs ARE NOT brackish water fish.>
There is also a home for him at the Koi fish pond at the local botanical gardens.
<Unless this Koi pond is somewhere tropical, then that's not an option either. These fish die when exposed to water temperatures below 20 C (68 F) for any length of time. In the US for example, Southern Florida is the only place where these fish are likely to survive outdoors in an unheated pond.>
We've made sure that he will have a place to go when we can no longer care for him.
<Hmm... not impressed so far with the options.>
Looks as if we'll just have to wait and see how icky fairs. Keep your fingers crossed for us! Thanks for the tips!
<Happy to help.>
Also, about the barbs - we'll definitely consider trading them in for more suitable tank mates. Any recommendations??
<Depends, and the thing with many schooling fish is that if you don't keep enough, many species can become nasty, even Danios. One of the single best schooling fish species in the trade is the X-Ray Tetra (Pristella maxillaris). This species is very hardy and very peaceful; it is also rather pretty. I don't care much for the albino form, but it exists if that sort of thing amuses.>
Much appreciation, Kristin
<Cheers, Neale.>

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