Sick CPDs

[bennyblee]

Hello, hoping someone could lend an opinion on my CPDs.

Over the course of the past month, I have lost 2 CPDs and my last one is sick now as well. I had started with 6, but they seemed to shoal very happily with my neon tetras so wasn't planning on restocking. I lost the first three months and months ago, all looked like they were developing bent spines and wasting away. They all happened at different times, there had never been a time with multiple sick fish together.

This month, I had one again develop a bent spine, rather suddenly it seemed, and then was clearly in distress so I euthanized it, about three weeks ago. This past weekend, another fish CPD disappeared, which I discovered yesterday (my tank is in my office at work), and I never found it, despite taking everything out of the tank. My final CPD was looking beautiful and healthy yesterday, today it is hiding and I noticed a flesh-colored growth that seems to have appeared overnight. I have attached some photos, sorry not the best quality. The other CPDs that I lose never had any visible lesions, they would just suddenly look bent, stop eating, and die within a couple days-weeks. The only major difference I can think of is that I stopped adding a baseline amount of aquarium salt to my water changes, in preparation for adding some cory cats (currently in my quarantine tank). But I've only done one exchange so far to reduce the saline.



Any ideas what this could be? As I said I am not planning on restocking CPDs, I have had a lot of difficulty with these fish. For a long time I assumed it was inbreeding as I don't know why they would all individually get a bent spine, on their own schedule, with all other fish looking perfectly fine.

Unfortunately, I don't have a hospital tank, as my usual quarantine/hospital tank is currently quarantining some new fish (week 2) I was planning on introducing... Should I euthanize this fish to avoid whatever this is getting passed long to the new ones? Is it worth treating the main tank? For what?

Thanks! Further details below.

1~CPD. Skin growth/lesion, very sudden onset. Hiding and not eating.
2~0/0/10/76F/7.8 (all very stable)
3~ 20G high, set up almost exactly 1 year ago, finished cycling and stocked 10 months ago
4~HOB filter, unsure what kind/power but plenty of bubbles at the drop in, which is what I look for usually...
5~Only now 1 CPD (~1 inch) and 4 neon tetras, ~1.5 inches
6~Last water change and gravel vacuum was 4 days ago. I do this weekly, or every 2 weeks at the very least if I have a vacation where I am away. I usually do ~20-30% PWE each time.
7~Fish are all ~10 months of age
8~I have been slowly converting to a planted tank, I added a bunch of column feeders (java moss, bacopa, various java ferns).
9~Rotate between Omega One color mini pellets and Fluval tropical flakes. Have recently started adding some Omega One Marine small pellets into the mix as I am adding some cory catfish (currently in my quarantine tank), and my LFS recommended these for the cats.

 

[bennyblee]

Update

D'oh! I may have spoken too soon. I just found a white lesion on one of my tetras. Do I have a columnaris outbreak?

 

[Colin_T]

I need better pictures of the fish to be able to identify anything on them.

Unless you have added new fish to the tank in the last few weeks, it's unlikely to be Columnaris.

You should not be adding salt (Sodium Chloride) to a freshwater aquarium unless the fish are sick and need treating with salt. Adding salt to freshwater aquariums on a regularly basis can cause kidney failure in fish that are not from brackish water.

The first lot of Celestial danios that died would have died from an internal infection or organ failure. Fish Tuberculosis (TB) can cause internal organs to rupture and the fish bend in pain, stop eating, do a stringy white poop, and die within 24-48 hours of showing symptoms. There is no cure for Fish TB. It might not have been Fish TB and the only way to find out for sure is to have a fish necropsied by a fish vet.

If could have been kidney failure due to being exposed to salt long term. If there were other chemicals in the water that would put more pressure on the fish's organs and may have contributed to their death.

As a precaution, you should avoid putting your hands or arms in the tank if you have any open wounds (cuts/ scratches/ sores) on your skin. If you have Fish TB (Mycobacteria species) in the tank, it can get into open wounds and cause a localised infection called a granuloma. These need treating with antibiotics and can often take months to identify and longer to treat. So avoid getting aquarium water on open wounds. You should also wash your hands and arms with warm soapy water after working in the tank.

Most people that get Fish TB granulomas have a weakened immune system but anyone can develop it so just be careful until you know for sure what killed them.

 

[bennyblee]

Thanks Colin.


I thought Columnaris could naturally colonize a tank, and didn't need to be introduced by other fish?


At any rate, so far so good. The lesion on the CPD is unchanged and the white lesion on the lip of the neon tetra is almost already gone. I am wondering if both were actually just physical injuries?


The CPD has come out of hiding and showed interest in food for the first time all week. Didn't each much but ate some today. I wonder if she was just stressed at having lost her last CPD friend and just needed a while to readjust? She is shoaling again with my tetras, they are all swimming together again. Maybe the tank balance got upset and she was getting bullied by the tetras which is where injuries to both might have come from?


I was adding salt because the owner of my LFS recommended adding a baseline amount to help promote healthy slime, as a preventative. I have read lots of conflicting stuff on the utility of it. Ultimately, I've come to the conclusion that it is probably bunk, it certainly didn't help my other CPDs from whatever ailed them. So I am gradually cycling it all out.

 

[Colin_T]

I thought Columnaris could naturally colonize a tank, and didn't need to be introduced by other fish?

If you have other fish tanks and ponds/ natural waterways nearby, you might get unlucky and have some harmful bacteria or protozoa land in your tanks. But generally if an aquarium is well maintained (regular water changes, gravel cleaning, and cleaning the filter), and the tanks have coverglass, there shouldn't be any disease outbreaks unless you add something (snails, plants, fish, ornaments) from another tank that has the disease organism in.

Columnaris is most commonly seen on neon tetras and guppies but can affect any fish. It usually comes into pet shops on fish from the suppliers.

At any rate, so far so good. The lesion on the CPD is unchanged and the white lesion on the lip of the neon tetra is almost already gone. I am wondering if both were actually just physical injuries?

The CPD has come out of hiding and showed interest in food for the first time all week. Didn't each much but ate some today. I wonder if she was just stressed at having lost her last CPD friend and just needed a while to readjust? She is shoaling again with my tetras, they are all swimming together again. Maybe the tank balance got upset and she was getting bullied by the tetras which is where injuries to both might have come from?

If fish panic and swim into something, they get a fat lip or a bruise and it resembles a white bump on the lip. It is common on fish that are newly added to an aquarium because it takes time for them to learn the environment. Having a picture on the back of the tank can reduce this, as can a layer of algae on the back and sides of the tank. Reducing the number of hard or sharp objects in the tank will usually reduce the chance of injuries like this.

The celestial danios are a schooling fish and need to be in groups to be happy. It's very possible the fish is stressed due to losing its friends and is now hanging with the neons for company. When things have settled down and everything has been good for at least one month, you can get some more if you want to increase the group size. But try to quarantine any new fish for at least 2 (preferably 4) weeks before adding them to an established tank.

I was adding salt because the owner of my LFS recommended adding a baseline amount to help promote healthy slime, as a preventative. I have read lots of conflicting stuff on the utility of it. Ultimately, I've come to the conclusion that it is probably bunk, it certainly didn't help my other CPDs from whatever ailed them. So I am gradually cycling it all out.

Salt (sodium chloride) irritates the fish a bit and they do produce a bit more mucous over their body. However, long term, it can do serious damage to the fish's kidneys, just like it does to birds and mammals. Too much salt is bad for you and for the fish, especially if the fish come from soft water with a low mineral content.

A low level of salt can be added to tanks that have a nitrite reading. The salt helps the fish get oxygen a bit more efficiently and helps counter the nitrite poisoning. However, once the nitrite poisoning is over, you get rid of the salt.

Higher levels of salt can be used to treat various diseases like minor bacteria and fungal infections, some protozoan infections, and a few other ailments. But as a general rule, you don't want salt in a tank unless the fish come from the ocean or brackish water.