About 50 CPDs dead... tank mates uneffected

[jwcarlson]

Title is pretty self explanatory.  

Made a few batches of fry in December last year and grew them out.  They've been fine until about 3-4 days ago I noticed one dead one.  I assumed it was because it got hurt when I used a pump to do their water change.  The next day a couple more dead and the last two days basically the remainder have died in mass.  One might still be alive.  

When the first one was dead I noticed some were fairly skinny.  None that I saw in the tank had any other obvious symptoms.  Still eating BBS.  My CPDs have always been very hide-y once they hit adult hood.  Last night I noticed a couple with fuzzy patches so I treated with Maracyn assuming it was columnaris.  I probably cleaned 15+ dead out this morning and a similar number tonight.  

Snails in the tank seem fine (there's some assassins, nerites, and bladder snails).  There's 3x furcata rainbows that have no symptoms and are still their boisterous selves.  One small BN pleco as well (seemingly unaffected).  No new additions to the tank or the fish room for months.

Unfortunately, I don't have any pictures of them... but I've never seen something move so fast.

I'm guessing there were some additional earlier signs that I missed because the tank is a jungle of floating hornwort.  

Nothing else in the fish room is having any issues, but it seems like I'm just waiting at this point.  There is a 10 gallon with a handful of CPDs next to this one.  There was a dead one in there a couple weeks (or more, possibly) ago, but didn't notice any other issues.

 

I don't really have a question, just a bit bummed.  I'd actually planned on selling all of these off very soon as I kind of had my fun with a big batch of them for the last half a year.  And they were good sized and had good color so figured they'd sell pretty well.  I'm glad I didn't do it this past weekend as that likely wouldn't have been a good situation.

[HelplessNewbie]

So sorry you lost so many. I would be quite disappointed, too

[nabokovfan87]

On 6/4/2024 at 6:14 PM, jwcarlson said:

My CPDs have always been very hide-y once they hit adult hood.  Last night I noticed a couple with fuzzy patches so I treated with Maracyn assuming it was columnaris.  I probably cleaned 15+ dead out this morning and a similar number tonight.

Fuzzy would be fungal, so you'd want to use malachite green or something like that.  Polyguard and ich-X being the two I have on hand for fungal as well as botanicals or salt.

Considering it's danios, the concern over NTD/Columnaris is a genuine one.  One tidbit that is often overlooked is temperature and pH and that contributing to general stress.  I would ask what the temp is, given things are warming up, and recommend adding a bit more oxygenation if you could.  Beyond that testing pH, pH swings and ensuring the hardscape didn't do anything funky and shift parameters on you.  Something also to rule out is just the general water source and what is going on before the water gets to you.   I've had my tap change drastically on me and it wasn't something I noticed apart from general issues inside the tank.

Netflix added the a movie called Dark Waters, it's worth the watch.
 

On 6/4/2024 at 6:14 PM, jwcarlson said:

I don't really have a question, just a bit bummed.  I'd actually planned on selling all of these off very soon as I kind of had my fun with a big batch of them for the last half a year.  And they were good sized and had good color so figured they'd sell pretty well.  I'm glad I didn't do it this past weekend as that likely wouldn't have been a good situation.

Best of luck with the resolution on this.  They are a beautiful, cherished species and the struggles you're having are something I can relate to. 

[Colu]

With how quickly they died if your water parameters are fine I suspect a fast moving bacterial infection such as columnaris the most effective treatment I have found is kanaplex and jungal fungus clear fizz tabs containing nitrofurazone following this treatment plan kanaplex and nitrofurazone based medication can be harmful to your snails if you needed to treat your remaining fish I would remove your nerite and assassins snails @jwcarlson

[jwcarlson]

I believe the last two in the tank were dead today.

Regarding stable water, I age and preheat all my water.  Water temp is 75-76.  Water changes of about 90% twice a week.  

pH settles around 8.2 or 8.3 after aging.  

Bare bottom tank with sponge filtration.  Lots of hornwort.

 

I didn't think about NTD, that's an interesting angle and would make a good amount of sense.  I slowly lost cardinal tetras over a number of years to what I believed to be NTD.  They occasionally had little patches of odd stuff that these CPDs had.  The cardinals took FORVER to die from it and it never affected anything but the cardinals.  

I appreciate the input from you two, @Colu and @nabokovfan87!  I'm going to do another big water change tonight and see what shakes out with the remaining fish... get the meds cleared out.  There's no symptoms in anything else, I've got kanamycin and the fizz tabs if needed.

[Colu]

On 6/5/2024 at 3:41 PM, jwcarlson said:

I believe the last two in the tank were dead today.

Regarding stable water, I age and preheat all my water.  Water temp is 75-76.  Water changes of about 90% twice a week.  

pH settles around 8.2 or 8.3 after aging.  

Bare bottom tank with sponge filtration.  Lots of hornwort.

 

I didn't think about NTD, that's an interesting angle and would make a good amount of sense.  I slowly lost cardinal tetras over a number of years to what I believed to be NTD.  They occasionally had little patches of odd stuff that these CPDs had.  The cardinals took FORVER to die from it and it never affected anything but the cardinals.  

I appreciate the input from you two, @Colu and @nabokovfan87!  I'm going to do another big water change tonight and see what shakes out with the remaining fish... get the meds cleared out.  There's no symptoms in anything else, I've got kanamycin and the fizz tabs if needed.

If it were NTD you would have got snout chondroma body lesion some spinal deformities these are commonly encountered when your fish have NTD

[jwcarlson]

I didn't notice anything like that.  To be honest, I only saw the fuzz/stuff on maybe 3-4 fish total.  As long as I got the dead ones out of the tank quickly enough, there didn't appear to be anything wrong with them.  

[Chick-In-Of-TheSea]

What a sad turn of events. I am so sorry @jwcarlson.

When you medicated did you add the extra airstone?

Edited June 6 by Chick-In-Of-TheSea

[jwcarlson]

I turned the air all the way up on the sponge filter, I don't suspect that was an issue.  The death rate didn't really accelerate after meds.  

There's three still alive as of this AM.  Did a big water change last night.  Only one additional dead one yesterday, but it could have been stuck in the plants until I stirred them up at WC.  Everything else in the tank remains fine.

Interestingly enough, I actually found my first baby assassin snails ever after having them for two going on three years.  I think the remaining CPDs are female and the main tank I believe is all males.  The CPDs still don't seem to be acting normal, but it could be that they went from 50 to 4 in about 48-72 hours and are hared out.

[Chick-In-Of-TheSea]

So weird that the other fish are fine.

Any temperature fluctuations? Do the CPDs have different temp needs than the other fish?

Edited June 6 by Chick-In-Of-TheSea