Corydoras panic: How do I fix this??

HaakonH · Post by **HaakonH** » 27 May 2013, 23:19

Right, this question feels slightly strange to be asking, as it may come across as some novice enquiry but...How do I stop my Corydoras from panicing?

First of all, let me share some info. In my main tank I keep a few different types of Corydoras. the tank is 540 liters, and heavily furnished with wood and plants, as well as open areas of sand. Lots of hiding places.

In this tank I've had a few different types of Corydoras during the last few months. The first group in there was a wild caught gang of C.ambiacus. They were always hiding, skitting off into dark corners as soon as they noticed my presence. I added a large group of C.concolor, and they were more out in the open, less afraid. It didn't help on the ambiacus though. There's a couple of CW002 in there too, just as scared as the ambiacus, but when I decided to remove the ambiacus and the concolor, I let the CW002 stay. Maybe a mistake, because I added a couple of CW039. They were out in the open to begin with, acting like normal Corydoras, but soon they were affected by the panicing CW002 and stayed hidden. A few weeks later I added a group of C.cf.ambiacus "Belem", 4 of them. They were out in the open for a couple of days, then they too decided to stay hidden. I added a group of C.eques, 3 of them. They had been in a different tank, where they were always aout searching for food. They acted normally for about a week after being moved, and now they too are panicing.

So I've got 4 different types of Corydoras in this tank now, and they are all very skittish, darting away quickly as soon as they see me. The barely come out for food, but mostly I see them sifting through the sand behind plants and roots in the shades. Sometimes I hear them crashing around in there, and I get a glimpse of a fish rapidly storming through the tank before disappearing into a dark corner.

I should mention that the tank is also the home for some other species of fish. I've got a few different l-number Plecos in there, which are acting normally, coming out to feed in a typical manner. I've got some small schooling fish (Swabwa resplendens, Danio margaritatus, Yunnanilus sp."rosy", Hemirhamphodon tengah) and loads of Cherry shrimps. So there's lots of movement and life around the Corydoras.

Water conditions are prime, filtration and current should be more than allright, lightning is not very intense...I can't find anything in the set up that should not be to the liking of Corydoras! And surely they do thrive, as they are all nice and fat and clearly feeding well.

It's like some trance they won't get out of, and it's like they contaminate each other with this panic. It's not cool. I know this kind of behaviour happens with Corydoras sometimes, but I would love to hear if anybody has tips on how to "cure" them. I'd like to see them enjoy their life, it's pretty depressing to see them like this.

Haakon

backstreetgambler · Post by **backstreetgambler** » 28 May 2013, 06:28

I too would like to know what to do about this problem. It really pains me to hear my C. Duplicareus and C. Arcuatus slam in to the glas panes in blind panic when I enter the room, all the while the other fish take little notice of my presence. It seems to me that this skittish behaviour gets worse as the fish get older.

donpetty · Post by **donpetty** » 28 May 2013, 07:54

Hi Haakon,
First let me say that I've read many of your posts and have learned a lot from you! Thank you for that.

With that said; I remember the following article which may or may not have any advice you can use.
http://www.planetcatfish.com/forum/view ... =6&t=33492

For myself;
99% of the fish I have are corydora's, all of my cory's are in 20G (US) high tanks, including the so called shy ones and they are out in the open with the exception of C. virginiae and the melanotaenia, which bolt as soon as they see any "fish-Keeper" movement. But, these fish settle back quickly and are out searching the sand again for treats.
One thing I would say is that my tanks are low light with only potted low light tolerant plants such as Ananias.
You mentioned well planted and you said lighting is not intense but, if the tank is lit with T5 or some type of plant light, this could be the cause of the "Fish- Anxiety"? My tanks have black back grounds so its not the brightest of environments. I do not know if this has a bearing on why your cory's are acting skittish, but you might try lowing the lite by turning off one of the tubes and see if they respond positively -or not?
Don

HaakonH · Post by **HaakonH** » 28 May 2013, 08:59

donpetty wrote:Hi Haakon,
First let me say that I've read many of your posts and have learned a lot from you! Thank you for that.

Thank you, Don! That is probably the nicest thing to hear for any forum user

Also, thanks for the link to the other topic! I probably should have responded there instead of starting another thread, but I didn't find it...anyway, there's some useful info there.

My tank has 4 x 30 w tubes, but only 3 of them are running. I will switch off another, so that only 2 are in use. The tank is mostly decorated with Anubias and Microsorum, so that should be fine

The back of the tank has a dark cover on the outside.

I'm starting to wonder if too many hiding places make these fish more skittish/less active out in the open. In the past, I've mostly encountered calm, active Corydoras that are always out in the open. I'm trying to figure out what the differences are in this set up and those where everything was fine, but there's not that much of a difference really. I've considered adding more active fish, but I don't think it will matter much since there already are active fish in there. I'll start with more subdued lightning and see what happens

Thanks again!!

Haakon

rmc · Post by **rmc** » 28 May 2013, 18:18

I'm not saying it's completely related, but I have a group of C. metae in a 20 gallon tank. For near 6 months they were always near the front of the glass feeding and laying eggs in spawning mops and on the glass. I added 4 small Ancistrus triradiatus to the tank and now the Corys scatter whenever I come in the room, and typically hide in the far back corner of the tank. They eat far less and have stopped laying eggs altogether. You wouldn't think 4 little bristlnoses would be all that frightening, but I think adding them to the environment has had a pretty large effect. How are the Corys that you have moved out of that tank? Still skittish?

HaakonH · Post by **HaakonH** » 28 May 2013, 20:35

That's strange...but it seems like there's a connection between adding the bristlenoses and the change of behaviour yes. It almost seems like if Corydoras are exposed to a frightening experience, such as tank refurnishing, fish being added, moving, etc they are prone to get stuck in their "fear trance"...

The C.concolor was moved into a much smaller tank (74 l.) which is also heavily furnished with hiding places. They share it with C.atropersonatus, Lasiancistrus heteracanthus and Nannostomus beckfordi. The tank is lit by 3 LED bulbs, so it's quite dim. In there, they act normal, always out up front!

The C.concolor seem to be a relaxed gang. Maybe I should put them back into the big tank and see what happens?

Haakon

rmc · Post by **rmc** » 28 May 2013, 22:29

My C.metae are in a similar sized tank (74l=20 gallons). It's brightly lit, but there is a lot of plant cover, so the bottom isn't super bright. I have C. concolor as well, they are in a tank about half that size - maybe 36-37l. They are the only fish in that tank and like yours are always up at the front. They may work better, but it is strange how their whole behavior changes tank to tank. I had 2 groups (in 2 tanks) of C. weitzmani for a while, the group I still have hides all the time, but the other group made up of smaller and younger fish were always at the front, tank décor was nearly identical, and no other fish in either tank. Maybe a change of scenery will help.

CoryfanAad · Post by **CoryfanAad** » 29 May 2013, 08:55

I have an Aeneusspecies with ecactly the same problems. They are in a 54 liter and goung to move them to a 100 liter because someone told me that could be the problem. Other ones (other Aeneus and pandas) are perfectly allright. I am anxious to solve the problem. My tanks are in a spare sleepingroom, so i thought it could be they were not used to movement aso, but as i said the others don't seem to bother. Also have thought about fish in the middle / upper of the tank which could give them a more safe feeling.

rmc · Post by **rmc** » 29 May 2013, 14:27

That's a good thought. What kinds of "middle water" fish do you use with your Corys? I've had good luck with Tanichthys albonubes, Sabwa resplendens, and some black Moscow guppies, but I've found some tetras can be a bit nippy. I'm always concerned about other fish being egg eaters though, so I try not to put them in my breeding setups. On an accidental spawning though I've found the S. resplendens and T. albonubes don't seem to bother with cory eggs.
On the panic note - the Corys in the tank with the T. albonubes seem to hide the least.

CoryfanAad · Post by **CoryfanAad** » 29 May 2013, 16:01

What I meand were not the nipping nasty ones, but more relaxed fish above them.
Lots of animals in the wild are only relaxed when they are in company of some specific other species that will warn them for danger aso. When my small Aeneus were in a communitytank they were totally at ease, now they are in a speciestank they are al lot more nervous.
An easy going bigger species could give them a better feeling.
Buttttt it's just a thought.

I've got Heterandria Formosa above them. But maybe they are the wrong ones / too small fot them.

Corycory · Post by **Corycory** » 01 Jun 2013, 03:09

The only time I experienced this was in one of several tanks with corys. It had been running for 2.5 years. From very healthy and active they became super shy. My pygmys used to be out all the time, then I couldn't see them for a week and more at a time and I had to search to find where they are hiding. So did the rest of the corys. If I approached the tank or did anything, like opening the lid, they'd be so frightened, they'd bump into the glass walls, really really stressed.
Coincidentally I had changed the substrate from river gravel to black sand because of the corys and re-arranged the tank as well, so I though the problem was the new layout stressing them and they needed time to get used of it. I tested ammonia, nitrite all 0s, Ph hadn't changed. However, the corys got sick about two months afterwards so there must have been a problem regardless and I ended losing a few. That's when I took notice something is wrong. I was never really sure where the problem came from...I medicated with several meds. The corys lasted for 6 months with this behaviour without improvement, until I moved all of them out from there as I was really worried. I took that tank apart and totally rescaped it. So it was enviromental.

The same corys are in a different tank now and are back to their very friendly behaviour. They come out to the front begging for food if I stand over the tank, total change of behaviour, and the tank is several times brighter than their previous one which was very low light/black background tank.

So my advise is, check everything. Clean the filters, give the tank a good clean, check under heavy decor, up the water changes, test the water, etc..Corys may show signs of stress ages before the worse comes, without necessarily dying.

CoryfanAad · Post by **CoryfanAad** » 01 Jun 2013, 08:18

Moved mine yesterday to another (bigger) tank. I am anxious if they will be more at ease !!

Coursair · Post by **Coursair** » 22 Jul 2013, 02:12

Sometimes adding to the group helps. It sounds like you only have a few of each species ?

In some cases bringing numbers up ( if you have room ) can help. 3 of this and 4 of that may not let them feel safe ??

In my small tanks I try for 5-6 of each species at least and ideal would be a larger group IME.

Best of luck

CoryfanAad · Post by **CoryfanAad** » 22 Jul 2013, 20:52

Moving them to a bigger tank didnn't do the job. This weekend i added another species (think leucomelas : id thread). Hope there will be a change. Strangely i noticed all of them scavaging through the tank when light were out. Even going to the light (of another tank) they didn't seem to be bothered. Maybe the mentioned low light is the key. Have frogbit in my tank to temper the light.

Supercorygirl · Post by **Supercorygirl** » 25 Jul 2013, 02:29

I haven't really experienced this except with the C. Melanotaenia (even with 8 still hide) but I'm wondering if the pleco species kept with them could be bothering them?