Very bummed. New bacterial infection going to wipe out my C. loretoensis

[Narwhal72]

I am really bummed right now.


Went home for lunch to check out my fish. Last night I decided to move my C. oiapoquensis out of their breeding tank because they weren't doing anything and move the C. loretoensis that I had been conditioning in. I put in 3 of the 4 I had (2M and 1F) and fed them some live blackworms and went to bed.

Today at lunch I went home to check on them and they look horrible. Soft tissue in the fins is white and eroding and the female's nose looks half rotted away. All of these fish were in perfect shape yesterday. Water was not changed and was same temperature as the tank the C. loretoensis had moved from. The C. oiapoquensis had been fine in it for weeks beforehand.

I added some alder cones and will do a water change when I get home to see if that helps but when faces start eroding fish are usually goners.

Really liked that cory. Probably my favorite one I have right now. Only good news is that there is another local breeder of that species in the area that I can get some from to replace my losses eventually.

Andy

[bekateen]

Sorry, man. That's no fun at all. Is it bacterial? Do you have any antibiotics?

Eric

[Narwhal72]

I don't see any redness but due to the suddenness of the infection it is likely bacterial.

I don't treat with antibiotics anymore. It's just a craps shoot without identification of the pathogen with antibiotics and most pathogens are resistant to the commonly available antibiotics. I will raise the water temp tonight and do a water change. Probably add some almond leaves too if they are still alive when I get home.

[bekateen]

Ok, best wishes.

[Mexnotex]

Sorry, really feel it. Love all corydoras. They have a kind of tranquility in them.
Maybe add some malachite green as a dip and transfer to a cooler tank with aquarium salt.

[jp11biod]

please let us know what happens overnight

[Narwhal72]

Both males were dead by the time I got home from work. Female was dead by morning.

Don't think it was an infection. I think it was likely the stress from moving from one environment to the other so suddenly. Although I have never had issues moving fish from one tank to another in my fish room there is a first time for everything.

Will change water and let it sit for a bit with some orange shrimp in it as canaries until after the holidays.

Only positive is I now have an empty breeding tank to try the banjo cats in.

Andy

[bekateen]

Sorry, Andy.

What size is the tank? Specifically, how tall? With my banjos, it's my impression that height may be significant because of the up-and-down cycling behaviors of the banjos when mating. To further this idea, the one time I witnessed egg release, it was at the moment that my banjos reached the top of their cycle (which was about 3/4 the way up the side of the tank). And then they shot their eggs upward toward the water surface (I believe that's why they don't swim all the way to the top - they need to leave some room above them for egg release). My tank is about 20-21 inches tall.

Perhaps the banjos will adapt the height of their cycles to the height of the tank and spawn in shallow tanks. I don't know, that would be nice. But since they are explosive spawners, it makes sense that they would want to swim up in the water column and then shoot their eggs upward to give their eggs the maximum drift time/settling distance for maximum dispersal on the current.

Good luck, Eric

[MChambers]

In my experience. C. loretoensis is not an easy corydoras to keep. I didn't have much luck, and I know others that have had disappointing experiences. I'm impressed that you have a local breeder.

[Narwhal72]

Thanks for the advice Eric. The tank was a 10 gallon but with your advice I am going to try it in a different tank that I have available that is much deeper.

MChambers, Thanks. I got them in October at the Catfish Cataclysm event in Madison. I lost one of the 5 by the time I got the auction bag home. But since then the 4 remaining ones had done well and the female had put on a lot of girth so I thought they were ready to spawn. I still have the one remaining male. We are lucky that there are a number of very talented cory breeders in the Milwaukee area.

Andy

[smitty]

@Narwhal72: Sorry to hear about your loss. I know how it feels. Good luck going forward.

[Phish]

Sorry to hear of the troubles.

Yeah, those are funny looking little guys, with their innocent look despite their long dorsal spine.

To me, it does sound like a bacterial infection, but I would need more noted symptoms to better ID what type of bacteria. And in turn, suggest the proper med to treat it. But since there are no longer living fish infected, it would be easier (and safer) to just bleach/chlorinate the whole tank. I would recommend disinfecting both, the entire breeder tank and the tank the C. loretoensis were originally conditioned in, just to be ease your mind of possible future outbreaks or cross contamination.

What were the water parameters/chemistry for each tank? (pH, KH, GH)
What was the water temp for each?

Does the breeding tank have high levels of dissolved oxygen, lots of circulation and warmer water?
Or does the breeding tank have low levels of dissolved oxygen and poor circulation?

[Narwhal72]

Thanks for the advice but I am more than reasonably sure it's not a bacterial infection.

Bacterial infections do not kill fish within 24 hours. No bacteria is that virulent. There was also no redness or hemorrhaging.

The loretoensis were in a central system before the move and everything in that system is normal. Disease is very rare in my fish room. Almost never happens.

The breeding tank contained 5 Corydoras oiapoquensis that were perfectly healthy before and after they were switched out with the loretoensis.

I am reasonably sure that the cause of death was poisoning due to the cory's being stressed from being netted. The breeding tank did not contain any chemical filtration and it's possible either the oiapoquensis or the loretoensis released their toxin in the water and poisoned either themselves/the others. I have had this happen before with C. gossei and C. robinae but this was in shipping bags and this was the first time in a tank.

Andy

[Phish]

But you said "Soft tissue in the fins is white and eroding and the female's nose looks half rotted away."
I've never heard of Corydoras toxins causing any damage like that? And I would think the cases in small shipping bags would have higher concentrations/worse damage than in a tank with a larger water volume.

I have a plausible theory that might explain what happened via infection (yes, the previous corys could be fine), but would need more info to determine if indeed plausible or not.
Tank sizes, pH/KH/GH, o2 levels, amount of water circulation, water temps, would all help to know (if conditions are ripe for this or that bacteria, then it can be a breeding ground for it, just "waiting dormant" for a vulnerable -stressed/weak- host/fish to come around).

Not trying to insult your knowledge, but I do have a pretty good understanding of many fish diseases and how many factors are at play, so I am just trying to help, but if that's not wanted, then carry on.

[Narwhal72]

I realize you are trying to help. But a theory needs to be supported by evidence. The evidence in this case does not support your theory.

And you are right the toxin can be in higher concentrations in a bag. It is also faster acting, I lost the gossei about an hour after I had bagged them up. But the effects on the fish are very similar looking. The whiteness on the fins is extra mucous production and tissue degeneration due to the effects of the toxin. The mouth damage on the female is curious but may actually have been the result of a physical injury which occurred during capture.

The bacterial infection doesn't hold up well to the evidence.
1. Fish were perfectly healthy and doing well up until the time they were added to the aquarium. 45+ days in quarantine since I acquired them and no symptoms of any infections. Fish were active and had put on significant mass. The remaining male fish in the original tank is also healthy and still doing fine as is the C. oiapoquensis in another tank. If it was a disease there should be symptoms in the other fish.
2. Although they were two different tanks, they both receive the same water changes with RO water. Water quality is essentially the same. Both tanks are on the same level in a fish room that is heated (no individual heaters). Stress from the change in environment had been one of my early theories but didn't hold up upon further reflection.
3. If a fish was was vulnerable or stressed and infected with a disease it should have progressed exponentially. IE one fish becomes ill, spreads infection to others, etc... To lose all fish simultaneously does not fit a disease progression profile.

I don't measure the parameters of my tanks unless I am doing a specific experiment trying to breed something difficult. I find that the test kit is the most dangerous tool in a fish room. Too many hobbyists spend so much effort trying to "correct" their water chemistry that they lose water stability. A stable environment is more important than a desired pH and hardness in most cases. My water is straight RO water and has a very low GH and a moderate amount of KH (due to dissolution from rocks in the tanks). When I have measured pH it tends to hover around 7-7.5. All tanks have an airstone in them.

I realize this question cannot be answered without an autopsy of the deceased specimens so I am content to just chalk it up to a lesson learned for next time.

Andy

[rmc]

Next time hit them with a simultaneous treatment of kanamycin and Furan 2. Knocks out fin rot (which is bacterial) every time. I've done this on at least 5 occasions with 100% success rate. My C.wotroi even grew back her tail from what can only be described as a "nub". Come over and get my loretoensis Andy, I don't have space to spawn them right now anyway. ;)

[catmandave]

Yes Andy, there is a Santa Clause! (rmc)

Check out Columnaris- this seems to fit the symptoms that you describe.

Dave.

[Narwhal72]

Thanks Rob. That's awesome. I will get with you to pick them up.

I am still pretty convinced it was self poisoning. Columnaris wouldn't kill fish within 24 hours. My remaining loretoensis is fine and after a couple of water changes and a week of letting it sit with nothing but shrimp I put in some loxozonus and they are also fine. Although they haven't bred yet.

Andy

[rmc]

24 hours! Sorry I didn't read thoroughly enough! Yes Agreed aggressive strain of flex(columnaris)!