CPD's dying one after the other

[Chad]

I started with 10 Celestial Pearl Danios over 6 months ago and am now down to 4, with it likely being 3 soon. Of the remaining 4, 3 are in superb health but 1 has a bent spine and I noticed a couple lumps on one side this morning. A few weeks ago, I lost the 5th one with a similar downslide. Sadly, I didn't notice the others missing until then. The CPD's play in the back of my busy community aquarium and it took me while to notice the thinning numbers. 

My conundrum is my tank's extremely healthy (seemingly). The parameters are perfect (0 ammonia and nitrite, 20pmm nitrate for happy plants). Water changes every other week. The water is crystal clear and all the other fish are doing great. The rummy noses are all nice and red-faced, the neons are fat, the cory's are playful and the cherry shrimp are numerous. The tank's over a year old and has been flawless. 

I'm at a loss. One CPD slowly goes downhill after the other. There is aggression between the cpd's with one hounding the others but the tank's busy enough with lots of hideouts if needed. I've seen columnaris before, this doesn't look or seem like it. I mean it might be, but the last two guppies in there are kicking around no issues. Again, everything is perfect and the model of healthy EXCEPT the CPD's. I know @Guppysnail has kept them for a long time (you're the reason I tried them out, and they're amazing!) and I always appreciate your insights, what do you think? Any thoughts are appreciated from better fish minds than mine, thanks!

[Chick-In-Of-TheSea]

Had you quarantined the CPD and looked for signs of internal parasites (such as white poop)?  Had you noticed any that were hiding or smaller/scrawnier?

Edited October 31, 2022 by Chick-In-Of-TheSea

[Chad]

I quarantined the sick CPD prior to this one, it became lethargic and died a day later but showed no signs of white poop or swim bladder issues. I did notice it would hang out on the other side of the tank, with the green neons. I did feed the tank med flakes (flubendazol?) for several days after that to hedge my bets.

[Chick-In-Of-TheSea]

Do you have any photos of the lumps?  Tagging @Colu & @Odd Duck to see if they have any ideas.

[Chad]

I'm sorry, I don't. I just can't get a good pic of it. He's still moving around full speed and eating great. 

[Chad]

Here's the best pic I could take. I know it's not great. But you can see the bumps on his side, top of body and two lower near the tail.

[Chick-In-Of-TheSea]

Do the bumps look fuzzy or fluffy, or are they kinda flat?  Also do they appear white or grayish?

[Chad]

@Chick-In-Of-TheSea Not fuzzy or fluffy, bumps so not flat but they are smooth. I'd say light grayish? Certainly not bright white.

[Chick-In-Of-TheSea]

On 10/31/2022 at 11:41 AM, Chad said:

@Chick-In-Of-TheSea Not fuzzy or fluffy, bumps so not flat but they are smooth. I'd say light grayish? Certainly not bright white.

Sounds like columnaris to me. The treatment is

the treatment is not safe for invertebrates (ie: snails, shrimp)

Also you’ll want to add a second airstone when using medication.

Here's a link to @Colu's thread about columnaris as well:

https://forum.aquariumcoop.com/topic/15673-the-most-effective-treatments-of-commonly-posted-diseases/?do=findComment&comment=130613

[Chick-In-Of-TheSea]

Also a mild dose of aquarium salt if you have it; it will help the fish with electrolytes and aid in recovery.  1 TBSP per 5 gal.

More reading material here:

 

Edited October 31, 2022 by Chick-In-Of-TheSea

[Colu]

What I would do is quarantine your CPD as it's only effecting them and  it's been happening over a long time and none of your other fish have been effected  I don't think that's columnaris theirs two things it could a bacterial infection some parasitic infection can cause over product of the mucus coating that can cause these grey flat patches first I would recommend treating with kanaplex and Jungle fungus clear fizz tab's containing nitrofurazone following this treatment plan that @Chick-In-Of-TheSea recommended it very effective treatment for more severe bacterial infection then I would follow up with a another course of the medicated flubendazole flakes feed every over day for 5 days then repeat in 2 weeks @Chad

Edited October 31, 2022 by Colu

[Guppysnail]

I have seen the scrapped patches. In mine it is missing scales from breeding or dominance fighting. Sometimes when breeding the entangling rubs one ir the other against hardscape. However mine are never skinny like the picture of yours. Mine suffered more fatal injuries when I kept 10 in a 20g. 20 in a 40 gallon reduced aggression and injuries. 
 

The thin sunken belly in yours plus multiple patches/ missing scales makes me think your issue is not what I have previously seen. 

[Chad]

Thanks everyone for the help! I appreciate it all and will start with trying to quarantine. I’ve got those meds in hand too so once in their own tank I’ll get it started. 

[modified lung]

I'm assuming you get them from your LFS? Most CPDs don't seem to handle stressful events like being shipped to your LFS very well. One or two stop eat and waste away, then the rest do the same one at a time. If you can find one, get them from a local breeder.

[Chad]

Actually I bought them from a reputable online store that I have had nothing but a great experience with. Nobody local sells them. They came in great health and have been just fine as far as I can tell. Again though, they’re shyer than most of the other fish I have in there so I wasn’t keeping as close a watch as maybe I should have. It’s a 33 gallon long tank.

[Chick-In-Of-TheSea]

On 10/31/2022 at 1:08 PM, Chad said:

they’re shyer than most of the other fish I have in there

Some fish tend to be shy/hide if the current in the tank is too strong for the species.  This may or may not be a factor here, but thought I'd throw it out there as a possibility.  Current too strong can also cause fish to become stressed/ill.

[Chad]

It's a fair concern @Chick-In-Of-TheSea. I'm guessing it's ok but I can't be absolute on that. I learned in a past aquarium what too little current/water movement does and I didn't want to replicate it. I use a canister filter on this tank but I have lots of slow spots and hides which the cpd's do utilize. My guppies and clown killi's don't seem to mind so I figure it's not too fast but I'm not experienced enough to say this with total certainty.

[Odd Duck]

I think you’ve gotten some very solid advice and concur with quarantine and treat just the CPD’s if possible.  @Coluis right on target and make certain your quarantine tank doesn’t have excessive water flow.  My CPD’s hide a fair amount in the sword plants and out of the main water flow.  They come out enough I think a healthy COD can handle flow, but sick, I’d bet they appreciate quieter waters.

[Chad]

On 10/31/2022 at 11:21 AM, Guppysnail said:

I have seen the scrapped patches. In mine it is missing scales from breeding or dominance fighting. Sometimes when breeding the entangling rubs one ir the other against hardscape. However mine are never skinny like the picture of yours. Mine suffered more fatal injuries when I kept 10 in a 20g. 20 in a 40 gallon reduced aggression and injuries. 
 

The thin sunken belly in yours plus multiple patches/ missing scales makes me think your issue is not what I have previously seen. 

So I had to put down the injured CPD yesterday. I had quarantined him but unfortunately he just wouldn't rebound. It did allow me to very closely inspect the tumors, and sure enough, they weren't tumors but scrapes. Chalk it up to old man eyes I guess, but it seems I have one dominant CPD that's reigning terror onto the others. Not sure what to do. I did recently add Endlers to the tank and those little buggers are all up in the CPD's face which certainly gives it lots to think about other than messing with the remaining CPD's. They're in a 33 long tank but I'm down to 3, with 3 more in quarantine at the moment. Should I remove the dominant one and see what happens? 

[Guppysnail]

On 11/8/2022 at 5:46 PM, Chad said:

So I had to put down the injured CPD yesterday. I had quarantined him but unfortunately he just wouldn't rebound. It did allow me to very closely inspect the tumors, and sure enough, they weren't tumors but scrapes. Chalk it up to old man eyes I guess, but it seems I have one dominant CPD that's reigning terror onto the others. Not sure what to do. I did recently add Endlers to the tank and those little buggers are all up in the CPD's face which certainly gives it lots to think about other than messing with the remaining CPD's. They're in a 33 long tank but I'm down to 3, with 3 more in quarantine at the moment. Should I remove the dominant one and see what happens? 

I’m glad it was not tumors. 
I have tried to remove to a time out the bully male. When I reintroduced the fighting got worse to re-establish dominance. 
I’ve come to accept their drama way of life as nature taking its course.  In a 33long my advice is add more. Like 10-15 more. My large group in the 40 B is the least violent. Aggression is spread way out and they have tons of room to run off that crazy excess energy.
More is better. kind of like cichlids. The only way to keep aggressive ones from my understanding is overstock with lots of room. 
I think CPDs are like miniature Oscar’s. 

[Chad]

I think you're right on the money @Guppysnail, thanks! I was thinking of cichlids but in super miniature form:) Oh well, unfortunately I can't add more since I just started going down another path of fish to keep. I only bought a few extras with my order to keep it a minimal school at least. But along with them I bought 10 platinum rice fish that came in very healthy and so far I'm excited to try and raise up their fry as my winter project. Anybody have any experience with rice fish in here?