What is killing my Cories?

I posted about this a while ago, and never really got an answer. But I have more information now, so it might be worth a try again. This is an issues that has slowly dwindled down my Bronze Cories from a single clutch, who are now over a year and a half old. No other fish have displayed these symptoms other than these siblings, and it's always fatal. The symptoms are always very similar. The Cory gets dark in color, starts breathing rapidly, looses its appetite, and eventually passes. They also sometimes develop milky eyes and go completely blind. It never affects more than one Cory at a time, and I'll go weeks or months in between one being afflicted by it. It has never affected the ones who are larger in body like their mother, only the more petite ones like their father. Tank parameters have no correlation to it.

When I see one that has developed those symptoms, I'm hesitant to move them for treatment because when I have tried to do so in the past, I think the stress of being relocated and being alone killed them before any treatment could take effect. (I also admittedly don't have any antibiotics on hand right now.)

The symptoms are reminiscent of a bacterial infection in some ways, but it doesn't act like a bacterial infection. It also doesn't have the redness that you commonly see in Cory bacterial infections. In all my research on fish diseases and Cory diseases, I've never found anything like this. It absolutely baffles me. I've lost sleep trying to figure this out. Just when I think that it's stopped, that I haven't seen one in months, a new Cory develops symptoms and shortly dies. I feel absolutely helpless, watching their numbers slowly dwindle over the months. There's nothing I can do, by the time the symptoms are apparent they are so far gone that treatment and recovery is nearly impossible, even if I figured out what the problem is.

I don't think their father was very genetically healthy. He died suddenly a few weeks ago. No explanation. Could this be some sort of strange genetic condition that has been going on this whole time? Breeding and raising my own catfish has been a wonderful experience, but in hindsight these guys should have never been bred.

I've included two pictures. One is the current sufferer of this thing, the second is one from a few months ago who went blind. I'm not sure if anyone will have answers. I'm just upset by this, it's so hard to watch.

 

sorry...fairly new here. I have Cories , and have lost one or two, but never saw any injuries or symptoms prior..they just up and disappear. I have older larger ones, and well as a couple of peppered cories and they all seem fine. I will be watching, and hoping someone else offers advice to you. I am so sorry for your problem.

 

It happened again. As I was doing tank maintenance I found another Cory, breathing heavily with both eyes clouded. I'm so angry, I'm loosing them one by one and nobody knows why. I don't know if I want to scream, cry, or throw up. I'm doing everything right for these guys but it doesn't matter. I feel like such a failure. No matter what I try they never live more than a few days after the symptoms appear. I don't get it. Nearly 2 years of nurturing these guys, watching them grow, loving them, and giving them the best care I can, and I'm doomed to slowly watch every last one die. I went from raising over 40 babies to a size big enough to be with their parents, down to only 11, soon to be 10. This is awful.

 

Im sorry. That really sucks. I have no idea what it could be though because I have never kept corys. Try dosing API melafix. It has teatree oil which is kind of an all around cure for ailments.

 

I’m so sorry. To me, it really does sound genetic. Maybe Corydork or CoryFan know something?

 

i’m so sorry, i can’t imagine how stressful this must be. i’ve always loved cories cute faces and playful attitudes. best of luck on returns to health!

 

In case this site didn't come up during your research...

Cory Env Dis F

This is a great resource. They will reply to your email and post on the site.

I hope someone can shed light on this issue.

 

Hi ! Cory catfish can have cataracts (or so I’ve read) try treating with otc tetracyclin and penicillin. I’m trying to do some more research for you ! I have never seen this hopefully we can get to the bottom of it.

Here is some more info I found, hopefully it might be useful.


Several things can cause cloudy eyes in aquarium fish. Internal parasites, such as protozoa or flukes, are one cause. Another is the onset of cataracts in fish. I’m not aware of any treatments for those problems. Bacteria can infect fish eyes damaged by injury. Treatment with a good antibiotic should cure these infections. Dietary deficiencies, such as lack of vitamin A, may contribute to poor fish eye health. The most common cause of cloudy eyes in aquarium fish seems to be poor water quality, especially when the pH level in the aquarium water drops too low.

 

Here is some more info I found, hopefully it might be useful.


Several things can cause cloudy eyes in aquarium fish. Internal parasites, such as protozoa or flukes, are one cause. Another is the onset of cataracts in fish. I’m not aware of any treatments for those problems. Bacteria can infect fish eyes damaged by injury. Treatment with a good antibiotic should cure these infections. Dietary deficiencies, such as lack of vitamin A, may contribute to poor fish eye health. The most common cause of cloudy eyes in aquarium fish seems to be poor water quality, especially when the pH level in the aquarium water drops too low.

I thought it was cataracts at first too, but the problem is that not every Cory who dies develops the cloudy eyes. I've read that excerpt before, and I ruled out most of the causes. It's not bacteria from an eye injury, all of the foods I give them have plenty of vitamin A, the water quality is very good and I stay on top of it, and the pH is high. The only possibility from that list is internal parasites, but that doesn't explain everything.

Even if this isn't the answer, I really, really appreciate you taking the time to research for me, that was so kind of you.

In case this site didn't come up during your research...

Cory Env Dis F

This is a great resource. They will reply to your email and post on the site.

I hope someone can shed light on this issue.

I've found that site before, but I had no idea it was still active, I'd only seen old posts. (Plus it looks like it hasn't been updated since the 1990's!) I will definitely check it out, thank you!

 

I think it's all about substance over style!

 

How is the waterflow / filtering Deku ?

 

How is the waterflow / filtering Deku ?

I have a Marineland Penguin 200 HOB, a Cascade 1000 canister, and a sponge filter. There's a good amount of flow from front to back, with no major dead spots. They enjoy the flow, one of their favorite hangout spots is on top of the sponge intake on my canister filter. They have lots of caves and thick plant growth to hide out in as well.

 

I think I have an answer for some of my recent problems. It doesn't explain everything, but it explains the recent issues. Gill Flukes. I've noticed my Cories flashing on occasion, but I didn't really think much of it. Yesterday I noticed my Cories were flashing quite a bit. Odd. Then I noticed my Cherry Barbs were flashing too. OK, something's up. I ran the usual battery of water tests, all were normal. So I decided to do a water change, in case something in the water was bothering them. With the light on to do a water change, I was able to get a better look at all of them. I noticed many of the fish had retracted gill plates and irritated looking gills. I knew immediately what I was looking at.

I had a bout of what I think was Gill Flukes with my Cherry Barbs when they were in quarantine. I treated with General Cure and that seemed to have fixed it. So I either didn't cure it, or this is something unrelated. It's crazy how quickly the symptoms showed up, I've been observing all of my fish closely (partly out of quarantine boredom) and I didn't see any noticeable symptoms other than the occasional flashing until yesterday. I have PraziPro ordered and it should arrive Thursday. Everyone is still active and hungry, so I'm hoping they'll be OK until it arrives.

I'm obviously very upset and worried about my fish having gill flukes, but in a way it's kinda a relief, that there's something tangible going on that I can actually do something about.

 

I had foolishly hoped that treating the gill flukes would resolve the issue, even though I knew deep inside that it wasn't true. I've found another one that I doubt will live through the night. Same symptoms. Heavy breathing, no appetite, dark color. I'll be down to nine after this one. I started with over thirty. Almost every. Single. One. has died from tjis godforsaken thing. I've tried everywhere. I've asked every person, every place I could think to ask. I've dug through dusty forums and obscure websites. I've scoured databases on fish disease. I've found NOTHING. Every person I ask, even experts, can't give me the faintest of answers. The only place I've gotten even close to an answer was WetWeb Media, who after going through several things that were eliminated as problems suggested that it was a genetic abnormality causing them to be extremely vulnerable to one of several nearly incurable bacterial infections.

I'm sorry, this has turned into more of a thread for me to vent on than an advice thread. This has just been so painful for me. Can you even imagine raising up fish from an egg for over a year, then having to helplessly watch them die one by one, in a manner that is clearly not a pleasant way to go? It's been a huge strain on me mentally. It feels like my fault, like I'm doing something wrong. I feel like I'm failing them. I give people so much advice on this forum but I can't even keep my own fish alive.

And even after two treatments of Prazi, I'm still seeing my fish flash. Their behavior and gill health has improved but something is still irritating them. ARGH. I'm not at the "I want to quit the hobby" level but I do definitely have that feeling of wanting to curl up in a ball and hope that this war with mother nature will end.

 

Did you have a chance to post on the site that I mentioned that got deleted?

Sorry you and your fish are on this roller coaster.

 

Did you have a chance to post on the site that I mentioned that got deleted?

Sorry you and your fish are on this roller coaster.

Yes, that was the one I mentioned as the only place that had anything close to an answer. Their theory would explain a lot. The symptoms my Cories experience are similar to what can be seen with a Mycobacteria infection. Which of course is nearly incurable.

 

I'm so sorry.

 

I'm so sorry! I don't have much to offer on this either, not having seen it before. The only thing I could offer is potentially to test other water parameters - you can get test strips that are meant for testing drinking water, and that will test metals and other parameters that we don't usually test for. It may not give any new answers, but it's something I'd probably be tempted to try just to rule in or out.

I had a couple of corys kept outside who died of what I'm fairly sure were gill flukes. I'd brought them in to treat them - they were surface-breathing constantly, one would even try to wedge itself into the bubble-stream from the airstone. Would keep their gill cover closed on one or both sides, also had clamped fins. Both died, but neither had clouded lenses at any point up to death. Both got it at the same time as well.

I've had 'fish TB' with at least one livebearer, basically confirmed by me getting it on my hand not long after as well (doctor didn't culture it, but living on the coast he's seen it frequently enough in fishermen that he didn't feel a need to. Took a wait-and-see approach, treated it by applying heat at home, and it resolved on its own thankfully.) That fish had a very emaciated appearance, shrunken belly even though it was eating normally. None of the corys in with it got sick, at least that I knew of (the pool is large enough that sometimes I don't see deaths, plus the shrimp/snail/scud clean-up crew in there is very efficient.)

The only other thing I could offer, is that if it is mycobacterium, or gill flukes, or most other disease-causing agents - would be to consider investing in a good UV sterilizer, added into your system and run it all the time. Something with long enough dwell time, something made for killing parasites and bacteria rather than just algae. I added a Vecton 600 to the pool after the TB issue, and I haven't had any other suspicious deaths since then.