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Cory pandas keep dying

pseudodiego

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Hi, I've just skimmed the thread but I see they were sent overnight and then they had a long acclimation. I don't have time at the minute to go into detail but if the others think I'm right then perhaps one would clarify, but this might be the problem. Overnight shipping and then a lengthy acclimation with the bag open to the air might be the issue. The fish pollute the water but it isn't a problem until you open the bag.
I really think that it's a problem with the shipping of that concrete species and not a thing with my sand. So you may be into something.

The last shipment was three days ago. Two have died, another two looks sick, and the other four are more or less ok: not super active, but searching for food in the sand as a group, as cories do. I don't think any problem with the sand would have killed those two so quickly.

They must be really sick when I introduce them into the tank, or some chemical of the tank is affecting them that doesn't affect the other fish.

I'll see how the ones that are ok fare, if I observe that they are getting sicker, I'll scoop them out and put them in a tank without sand.
 
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Doogle

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I wonder if that stuff is black diamond blasting sand? If so that stuff seems to have mixed opinions online if it is toxic or not, I lost 2 of my three lined corys which I suspect was due to my black gravel as the remaining 5 didnt look great either, switched to playsand and they bounced back, all in good health and love sifting/burying their faces playsand as it has smooth granules.

Not sure if it was due to the gravel or maybe waste getting stuck between the gravel and rotting into nastyness.

None of my mid water fish died during this time but I did lose a few shrimp (now they are everywhere).

Not sure if this anecdote helps but it hopefully shows substrate alone can affect bottom dwellers while midwater fish do fine.

*edit: sorry was Tahitian Moon Sand that has mixed opinions regarding toxic heavy metals, forgot why I didnt go for blasting sand, think blasting sand has sharp granules but isnt toxic.
 
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pseudodiego

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I wonder if that stuff is black diamond blasting sand? If so that stuff seems to have mixed opinions online if it is toxic or not, I lost 2 of my three lined corys which I suspect was due to my gravel as the remaining 5 didnt look great either, switched to playsand and they bounced back, all in good health and love sifting/burying their faces playsand as it has smooth granules.

Not sure if it was due to the gravel or maybe waste getting stuck between the gravel and rotting into nastyness.

None of my mid water fish died during this time but I did lose a shrimp or too (now they are everywhere).

Not sure if this anecdote helps but it hopefully shows substrate alone can affect bottom dwellers while midwater fish do fine.

*edit: sorry was Tahitian Moon Sand that has mixed opinions regarding toxic heavy metals, forgot why I didnt go for blasting sand, think blasting sand has sharp granules but isnt toxic.

If your shrimp were affected, it isn't the same I think. I have 5 Vampire shrimp that live constantly in the ground, and I have keep some neocaridinas and amano shrimps without problem too.

Here is a review from another user on the sand:

"i was a bit concerned buying this as there were no reviews on here yet, but decided to give it a go, as it was such a good price compared to others id seen, i was worried about cloudiness ect, but this sand is great, i rinsed it thoroughly {packaging said to rinse until water runs clear, it was clear straight away, though i did continue rinsing just incase) i then soaked it in water conditioner before adding it to the tank, my tank was already full of water and this fell beautifully straight to the bottom of the tank, no clouding or anything it just settled beautifully, there were a few air pockets which made a few bits of sand form little balls which floated about, but you just pop them and they fall to the bottom too, it has a lovely deep black colour, although when i put the bright light on in the tank it makes it look brown, but i don't often use this light, so that's not a problem, it also went a lot further than i thought it would and i have plenty left for my large tank when i get it, i will be aquascaping the large tank so although its massive i will only use it at the front, as the back will be soil and plants. my corydoras seem absolutely love it, its nice and soft for them to big around in :):) i'm so happy i bought this and i highly recommend it :):) also was very quick delivery and great price"
 
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Conort2

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The last shipment was three days ago. Two have died, another two looks sick, and the other four are more or less ok: not super active, but searching for food in the sand as a group, as cories do. I don't think any problem with the sand would have killed those two so quickly.
Can you provide pictures of the ones that are alive please?
 

John q

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Overnight shipping and then a lengthy acclimation with the bag open to the air might be the issue.
I'd be tempted to go with this as the probable cause.

I know some people have success with buying fish online but personally I'm not a fan. If these fish were in a bag for 16hrs then waste levels will increase. The ph level will probably be low until you open the bag due to co2 build up, but will then rise once opend, any unharmfull ammonium will be converted to ammonia and likely have a detrimental effect on the fish.
 

pseudodiego

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I'd be tempted to go with this as the probable cause.

I know some people have success with buying fish online but personally I'm not a fan. If these fish were in a bag for 16hrs then waste levels will increase. The ph level will probably be low until you open the bag due to co2 build up, but will then rise once opend, any unharmfull ammonium will be converted to ammonia and likely have a detrimental effect on the fish.
Thing is, I buy all my fish like this, and it's very strange occurrence for those fish to die. tetras, gouramis, bettas, shrimps of all types, danios, loricariidae, etc. It only happened to me with the panda cories, and in three different ocassions from different vendors.
 

Nont

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I’m sorry for your loss.

From what I read, it seems like Panda cories are prone to everything.
Take a look at all these threads:
Panda Cories keep dying | Corydoras Forum | 168802
 

pseudodiego

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Another one died. 3 of 8, and another is having trouble staying in normal position, I think it'll die soon too.

Just caught this on video from one of the "ok" ones. It did it a couple on times in 15 minutes, but the other four doesn't seems to be doing it. Not sure if it might be related or if is normal cory behavior.
ezgif-5-783d52919f.gif
 

Conort2

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Another one died. 3 of 8, and another is having trouble staying in normal position, I think it'll die soon too.

Just caught this on video from one of the "ok" ones. It did it a couple on times in 15 minutes, but the other four doesn't seems to be doing it. Not sure if it might be related or if is normal cory behavior.
ezgif-5-783d52919f.gif
Maybe gill flukes? It’s breathing quite rapidly and the flicking is something I’d associate with it.

Corydoras panda are mass produced fish alongside Aeneus and Paleatus. These often seem to arrive in questionable condition. What exactly is your substrate? I can’t view the link as it’s Amazon USA.
 

pseudodiego

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Maybe gill flukes? It’s breathing quite rapidly and the flicking is something I’d associate with it.

Corydoras panda are mass produced fish alongside Aeneus and Paleatus. These often seem to arrive in questionable condition. What exactly is your substrate? I can’t view the link as it’s Amazon USA.
 
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three different ocassions from different vendors
Realistically even though you have got these pandas from 3 different stores/sellers there is still a chance that they are coming from the same place.... a lot of stores in the UK get their livestock from the same suppliers (even if you are not based in the UK I wouldn't imagine this practice varies much in other countries but could be wrong)

My experiences with pandas is that for some reason they are more susceptible to just dying for no apparent reason. As another poster has mentioned maybe because they are mass produced in a lot of cases
 

mort

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Were the cories active in the bag before you started acclimation? Just trying to rule out acclimation stress. We would get cory shipments with far larger numbers and they often looked ropey in the bag so we got them out straight away. It depends on how they were packaged but most wholesalers just temperperature acclimate the fish by floating the bag and then cut the top off and take the fish out straight into new water. We did the same with our imports and never knowingly lost a fish this way.

The problem is its hard to rule anything out at the moment. It could be rough handling in the post, an acclimation issue, poor stock or disease. Can you describe any symptoms in as much detail as possible. I can't see the vid and trust Conort2 with his fish knowledge but ammonia poisoning will also show as heavy breathing and similar symptoms to flukes, so it's hard to rule anything out at the moment.
 

pseudodiego

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Were the cories active in the bag before you started acclimation? Just trying to rule out acclimation stress. We would get cory shipments with far larger numbers and they often looked ropey in the bag so we got them out straight away. It depends on how they were packaged but most wholesalers just temperperature acclimate the fish by floating the bag and then cut the top off and take the fish out straight into new water. We did the same with our imports and never knowingly lost a fish this way.

The problem is its hard to rule anything out at the moment. It could be rough handling in the post, an acclimation issue, poor stock or disease. Can you describe any symptoms in as much detail as possible. I can't see the vid and trust Conort2 with his fish knowledge but ammonia poisoning will also show as heavy breathing and similar symptoms to flukes, so it's hard to rule anything out at the moment.
Not super active, but no floating problem or anything like that.

They seems to breath fast, they act very passive and after a few days they swim weird, getting sideways. A few days later, they die. The video shows one of them scratching against the ground, but that doesn't seems a widespread issue.
 
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mort

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Still very hard to narrow it down. Ammonia poisoning can cause fast breathing and lethargy before the fish deteriorate further and pass. I don't know if flicking is a symptom, or at least not one I've heard (perhaps @Conort2 or @MirandaB have come across it). If you look closely at the fishes gills you might see signs that pinpoint this and if the bodies develop red areas it could also suggest this might be the problem.
Gill flukes as suggested earlier is another disease that present in this way but often symptoms are common among various disease so it's very tricky.
 

mort

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Hi, I've just skimmed the thread but I see they were sent overnight and then they had a long acclimation. I don't have time at the minute to go into detail but if the others think I'm right then perhaps one would clarify, but this might be the problem. Overnight shipping and then a lengthy acclimation with the bag open to the air might be the issue. The fish pollute the water but it isn't a problem until you open the bag.

I didn't see this thread before but it has the explanation of what I was thinking


 

arcturus

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@pseudodiego : have you reported this issue to the fish stores from where you are buying the pandas? At the very least I would ask them about the water parameters they keep these corydoras in (pH, dKH, dGH, overall TDS). If these parameters are similar to the ones in your tank, then I would just plop them in the tank as soon as they arrive to avoid potential ammonia poisoning (and keep the bag sealed until you put them in the tank). You could ask the vendors to ship the corydoras in several bags, ideally just one fish per bag. This should not be an issue because the styrofoam transport boxes are usually big enough to hold several bags. I am assuming these fish were shipped together in a single bag, since this is the usual (and bad) practice with small fish. But this situation is very hard to diagnose and can be something in your tank.
 

MirandaB

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If they were shipped together in the bag I'd say that's the most likely cause of the issues...problems due to ammonia building up in the bag and then subsequent acclimating are usually pretty instant.
I've only had that happen once when some fish were sent to me with too many fish in bags that were way too small,within 2 minutes of opening the bags they went belly up due to ph drop....never had a problem acclimating before or since.
 

mort

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I don't know if the problem is becoming more prevalent but I've seen quite a few people suffer with possible shipping issues and I wonder if it's partly because postal costs have risen, so some suppliers are minimising the amount of weight by reducing water. Certainly here sellers that use royal mail, often keep weight down to the cost of the fish.

Were these fish sent in a large/adequate poly box or was it a bit of a squeeze?

Sometimes sellers also ship fish out that have only just recently arrived and multiple shipping stresses can really do some damage.
 
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