True or Myth : Columnaris is Found in Almost All Tanks ?

A lot of people say columnaris is found in almost all tanks but only become dangerous when the fish become weak/sick enough to let the bacteria take its toll. I personally don't believe the bacteria is found in most tanks. For example, there's the story of a fishkeeper (Link provided bellow) on YouTube who always quarantined her new fish before putting them in the new tank. One day, she decided to not guaranty her new fish because the fish that she bought from a particular shop were always healthy, so she thought it would be safe to not guaranty for once. Eventually, the new fish started showing columnaris symptoms and started dying. Not only that, but the older fish in the tank, whom she quarantined before, also became infected and died.

The logic is that if columnaris have already existed in the tank prior to her introducing non-quarantined fish to the tank, then how come her older fish only got attacked by the bacteria after the non-quarantined fish are introduced ? It's the same story of my tank where before buying a new batch of fish, my fish never showed any symptom of columnaris disease. It is only after the new batch arrived that my older fish started to get the problem. If columnaris have already existed in my tank before, then how come the disease became profound after I bought the new batch ?

Source of the story :

 

Seems like your correct conclusion to me. Adding new fish is always risky without quaranting them.

 

Seems like your correct conclusion to me. Adding new fish is always risky without quaranting them.

43 years of having fish and never once did I quarantine a fish. Lucky? I guess

 

I'd be inclined to believe its always present. I'm sure you could swab and culture bacteria from my skin, and find Streptococcus pyogenes. Doesn't mean I have an active infection of strep throat. Bacterial loads, active infections... blah, blah, blah

 

Bacteria and Ornamental Fish



Review of Bacterial Diseases of Aquarium Fish



Development, Characterization and Early Evaluation of New Modified Live Vaccines Against Columnaris Disease

 

43 years of having fish and never once did I quarantine a fish. Lucky? I guess

Wow that many years and not one case of ich or a new fish dying? Thats amazing. Hope you can continue your success.

 

There's not much point to quarantine for columnaris or fungal or bacterial infections or anything that's naturally found in the water. Those are caused by poor water quality and removing the sick ones in quarantine will not prevent your own tank members from getting it if your own tank does not have good water quality. You can add perfectly healthy fish to your tank and if this bioload becomes too much for the tank to handle, then these diseases will appear even if you quarantined the new fish.

Quarantine only makes sense for unique diseases not naturally found in water. In which case, they may be carried by perfectly healthy fish and you won't be able to tell who has it even with quarantine. The only solution would be to do a "reverse quarantine" (just made this term up) where you take 1-2 members out of your main tank and mix them with the new fish, and if your old livestock gets sick despite good water quality, then there may be some defenseless disease from the new fish.

At the same time, this also applies the other way around, in which your new fish may not have defense against some unique disease your main tank fish has.

Thus, to address both of these scenarios you have to do a "double reverse quarantine" in which you take a few members from the new fish and mix with a few members from your main tank. If either member gets sick despite perfect water parameters then you know there may be some defenseless disease around.

This is probably out of scope for hobbyists but is a definite concern for commercial breeders. I believe most aquarium fish species are not genetically homogeneous enough for this to be a problem, and from the anedoctes I've seen; usually the entire group of fish dies and the breeder just moves on. But for some of the highly inbred species like discus, high grade cherry shrimp, crystal red shrimp, etc etc I can see this becoming a real problem in the future.

 

I kind of disagree with some of this^^^^

I'd prefer to watch new fish and make sure I'm not increasing the bacterial load in the tank by placing a fish with an active infection in there. Everyone's immune system has a breaking point....

The "reverse quarantine" and "hero fish" concepts seem to be common in certain circles, no disagreement there.

 

I kind of disagree with some of this^^^^

I'd prefer to watch new fish and make sure I'm not increasing the bacterial load in the tank by placing a fish with an active infection in there. Everyone's immune system has a breaking point....

The "reverse quarantine" and "hero fish" concepts seem to be common in certain circles, no disagreement there.

If you are talking about transmission of these common freshwater diseases, it is closely tied with population density. Keeping density below a certain point will reduce transmission if one fish is infected. Quarantine is not going to achieve that. Quarantine tanks are usually small, much smaller than a hobbyists' main tank. This means that adding the fishes to a quarantine tank would just result in extremely high density and getting all the other fish infected, whereas adding them directly to the main tank would be lower density and a better chance of having the infection die out.

Here's a study on columnaris transmission: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2761.2005.00631.x

 

If you are talking about transmission of these common freshwater diseases, it is closely tied with population density. Keeping density below a certain point will reduce transmission if one fish is infected. Quarantine is not going to achieve that. Quarantine tanks are usually small, much smaller than a hobbyists' main tank. This means that adding the fishes to a quarantine tank would just result in extremely high density and getting all the other fish infected, whereas adding them directly to the main tank would be lower density and a better chance of having the infection die out.

Here's a study on columnaris transmission: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2761.2005.00631.x

I think I'm going to have to agree to disagree. I'd gladly risk the lives of 4 coryadoras catfish in a QT tank that's too small before I risk the entire stock of my show tank. Especially when the camallanus worms pop out at week 3

 

I believe:

It is true that Columnaris bacteria are present on surfaces in virtually all freshwater systems including our aquaria.

Columnaris bacteria live on the skin of our fish naturally without harm.

Certain strains of Columnaris bacteria can attack our fish and use them as a food source, particularly if their immune systems are compromised by stress.

Stress includes transportation, new environments, new water conditions and new tankmates.

Virulent strains of Columnaris bacteria are promoted by the methods of farming at high densities.

Resistant strains of Columnaris are encouraged by the methods of treatment in the farming environment.

 

I think I'm going to have to agree to disagree. I'd gladly risk the lives of 4 coryadoras catfish in a QT tank that's too small before I risk the entire stock of my show tank. Especially when the camallanus worms pop out at week 3

I agree with you. I never have breakouts in established tanks unless i introduce a new fish. If you can't quarantine a new fish make sure in in the dealers tanks a week or so [if they wont save it you might lose it] and make sure its eating and looks healthy.