FAQs on Corydoras Cat Social
FAQs on: Corydoras
Catfish Health 1, Cory Disease 2,
Cory Disease 3,
Cory Disease 4,
FAQs on Corydoras Catfish Disease by Category:
Nutritional (e.g. HLLE),
Bacterial, Fungal), Parasitic (Ich, Velvet...),
Summer loving: cats in the garden, kittens in
the kitchen by Neale Monks,
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
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.)
Quick question about Corydoras catfish 5/11/10
I was just wondering if it is harmful to keep just one Corydoras
<"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!>
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
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
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
<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
<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
<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
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
<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
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
<Beyond clean water, I'd not do anything else apart from
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.
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
<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
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
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
There is also a home for him at the Koi fish pond at the local
<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