Help with diagnosis...

[pacificdiver]

I had 6 small yellowtail damsels in quarantine, and one by one, they've been picked off by whatever this is. I ran Cupramine from day one, as directed, and 6 weeks in, the last one dropped. Whatever it is, it kills pretty quickly, within about 48-72 hours, once feeding stops. Cupramine and Chloroquine phosphate don't seem to have any effect on it. After the first two were lost, I tried 2 in a separate CP hospital tank, with the same results; they both died within a day of each other. They always start with loss of appetite, then sit on the bottom of the tank until they end up with white, colorless scale patches => then death a few hours later.

Any idea what this is, based on the photo? It seems like velvet, based on the speed, but it doesn't look like any velvet I've ever seen. Any help would be greatly appreciated.

[JustinM]

We’re you running cupramone at therapeutic levels? Cupramone and CP pretty much handle all diseases except brook and flukes. With Brook it’s easy to spot. Did you see any symptoms?

[pacificdiver]

Originally Posted by JustinM

We’re you running cupramone at therapeutic levels? Cupramone and CP pretty much handle all diseases except brook and flukes. With Brook it’s easy to spot. Did you see any symptoms?

Yes, cupramine and CP were both run at midrange levels (independtly, never mixed). Cupramine 0.3 to 0.4 mg/L and CP 60mg/gal. No spots, no films, just extreme lethargy. They all did exactly the same thing, stop feeding => sit on the bottom for a day or two => develop colorless scales in patches => death within a few hours. Frustrating stuff.

[JustinM]

It’s really hard to say. I don’t think uronema because you were dosing CP and that has proven pretty useful. It could be a gram negative bacterial infection but I’m not sure. Then you have mycobacterium as well.

Did it look like this in your tank while it was alive?




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[JustinM]

Most of the time with bacterial infections, it usually only takes out a fish or two. Being that it was a QT, conditions probably weren’t the best and an infection can take them all out. Here is a good read on bacterial infections.

https://www.thespruce.com/bacterial-...m-fish-2925202

It wouldn’t be a bad idea of sterlilizing the qt.

[pacificdiver]

Thanks, Justin. It looks remarkably similar to the photo you posted, but once the patches show up, the fish dies within a few hours. I have some Marycin I and II so I'll keep that in my back pocket if I see this again.

[JustinM]

That is a picture of a bacterial infection. Your qt should be sterilized to prevent the same infection from happening again.

There are many different antibiotic options but the most used are kanamycin, metrodozanole, and furan 2. They will pretty much cover a wide range of bacteria.

[Jdub968]

How were you measuring cu levels ? Also i agree with Justinm unusual for all the fish to die of bacterial infection I'm leaning two ways one is cu wasn't measured correctly or brooklynella
I think aggression can be ruled out on this one also