One of my Panda Corys died unexpectedly

[rimbaudsarm]

The other day I did my normal checks before going out for the day. All appeared healthy & well. On my return home I discovered one of my two Panda Corys had died. (The other was & still is perfectly healthy) A couple of days before I had visited my local aquarium shop & had my water quality checked. They told me it was perfect. There is no sign of any illness in the tank both at the time or since. the only thing I can think of is that the night before the tank was perhaps slightly overfed. Does anyone know if this could be likely or are there any other suggestions out there?

[MatsP]

What temperature is your tank?

--
Mats

[rimbaudsarm]

What temperature is your tank?

--
Mats

I don't know exactly, off-hand, since the only net connection I have is in internet cafes etc. However, if I describe to you the thermometer that has the 'green zone' marked on it, commonly available in almost any pet shop, then the temperature is at the top of this green zone. Does that help?

[DutchFry]

yes that helps, i have this thermometer too. that means the temp is around 26 or 27 degrees celsius.

i don't think the cause of dead is related to this temperature.

maybe it has to do with digestion system? did the cory have a very filled belly? did you noticed parasites around the anal area? did you perform authopsy on the fish?

[MatsP]

Well, that doesn't tell me much, since the "green zone" may be right for some fish but not others - and I don't really know what temperature that is.

The point here is that Panda cories prefer slightly cooler water than most tropical fish, so a lower temperature may be better for these fish.

--
Mats

[NEONCORY]

First sorry about your Pandas,rimbaudsarm.

And second I agree with MatsP. Since Panda is originally came from the cooler temperature water river although most of them are many, many generation away from the wild specimen.

Since you have not provide enough information. I'll tell you what works for me with Panda.

I have some breeding group and many frys and eggs. I usually get eggs once or twice a week.
I used to have 5 adults in 10G tank by themselves. Now I have 10 adults and 5~6 frys that reared on their own. The tank is unheated(room temperature of around 68~75F normally but little lower in Winter and little higher in Summer. And there are 2 powerhead with sponge attachment in the tank at the moment. They do enjoy the brisk water movement which also produce high oxygen. Which I believe they need to live well and healthy for long term. The water is 6.8~7 PH, I do not know the GH since don't have the test for that but I think they would do better in soft.
I know it is getting more crowded and considering to move them to bigger tank or split in 2 groups although I do daily or every other day water change since I need some of their water to change the fry tank water.
I know the usual pet store suggest that they would fine in the many community tank set up but I find them do better if you can give them their own tank if possible. And definitely you need to pick their tankmate carefully. No aggressive or too big fish and too active fish that out compete the food.
And just like most other fish, they do need some cover and hiding places. I have sands on the bottom with some bigger rocks and some driftwood and tons of Java Moss. As a matter of fact, about half of the tank is occupied by the Moss. Also I find the Moss is useful to protect the eggs better(the adults do eat the eggs if they can find). Also they do like to place the eggs in the Java Moss. Sometimes on the glass especially near the water from the outlet hit but majority I find inside the Moss.

So anyway, here is a few conditions they do better in.

1. high oxygen(more so than other corys)
2. cooler water(which hold more oxygen than higher temperature)
3. frequent water change probably 50% weekly or so(I do daily since I need water for the fry tank but I know this may not be possible for some people. I know the Corydoras can take air from the surface but if I see them doing frequently I will do the big water change as soon as possible. And yes, some reason they do go to the surface for gulp of air around their feeding time. I don't know why but I notice they do it more often go up to the surface when the feeding time. As if they concentrate to eat so much that forget to breath. Anyway, but any other time, if you see them go up for surface for air one after another, that is a yellow flag. And most likely that the water is not good and need to increase the oxygen in the water. Either water change or place some extra air stone or both.
4. keep them in big group(should be 6+ but 4 is minimum in my opinion. Once I tried to keep one pair but they were not as happy or as active when they are in the bigger group)
5. choose tankmates carefully although I highly suggest they are kept on their own.
6. And feed them well and many variety of food.
7. and get healthy fish preferably from the local breeder if you can find.(aquarium society or club is good place to look) Since the mega pet store usually get from mass produced hormone dosed fish from some Asia. And they tend to be fragile and weak. Actually some of the mega store around my area don't even carry them anymore which I suspect that they too had tough time keeping them alive before they can sell or too many dead before their guarantee expire. Same goes with long-fin variety since they are created by selectively bred and their gene pool is narrowed considerably.
8. I would recommend you to have established quarantine tank ready before even thinking about bring these fish home. If you get these fish, please take them home as soon as possible. Shorter trip is better. And take extra long time to acclimate them to your water. And the water parameter should be close to whatever the water parameter they were kept. You need to ask the store or the person you are getting them from. I mean in a long run it would be best to kept in the water condition I mentioned above however they do not do well in sudden change. And most of the case, they were kept in the local tap water if you are getting them from the local store.

To me they are one of the prettiest and cutest Corydoras and they do deserve their own tank. Also they would be more active and you can see them going all part of the tank. Especially they would swim against the water current. So they would fill the top and middle tank although they are suppose to be bottom dweller.

Anyway, good luck with your Panda. To me they deserve the best condition I can provide. And they must be pretty content that they give me eggs regularly since last November before then they were still too young. And now it is almost end of Summer so I think they are year around spawner. It is about this time I got my group of 6 last year. And they start breeding few months later. And I sold/trade many group of off springs to other aquarium members and I have many different size of frys and some eggs from few days back.
So it can be done.

[rimbaudsarm]

The other day I did my normal checks before going out for the day. All appeared healthy & well. On my return home I discovered one of my two Panda Corys had died. (The other was & still is perfectly healthy) A couple of days before I had visited my local aquarium shop & had my water quality checked. They told me it was perfect. There is no sign of any illness in the tank both at the time or since. the only thing I can think of is that the night before the tank was perhaps slightly overfed. Does anyone know if this could be likely or are there any other suggestions out there?

Additional information a day later than the above.

Firstly, thank you all for your help it is most useful.
Thermometer reads at 74-75F. I do suspect, however, since temperature for these little darlings is so important, it was very much a weather thing. It happened on a particularly hot day and the flat was very oven-like when I got back. Although my tanks never recieve any direct sunlight there really is nothing I can do about the weather, except to anticipate it more accurately and adjust the heaters to counter excessively hot days.
Next question, really is how low can I turn this temperature as I am told my clown loaches need this kind of temperature or they become prone to white spot.
One other thing, I always buy my fish from one single source who have been in the fish business for many years and are well established. And absolutely never from any pet shop or large chain. Only been keeping fish for just under two years and have, so far, been very successful. (Two of the earliest fish I got were my bristle noses and they have now got to about 12cm and are very much the rulers in their tank!)
Once again, thank you all for your help.