Prophylaxis for chromis (and other Uronema prone fish)

[Humblefish]

Enough is enough! After encountering recent failures to eradicate uronema via metronidazole, acriflavine and FW dips; I highly recommend using formalin to pretreat any chromis and other Uronema prone fish. Anthias are also very susceptible, but I sometimes see Uronema on damsels, clownfish, butterflies and angels.

Any fish you suspect is carrying Uronema should get a 45-60 minute formalin bath before entering your DT or QT. Do the following:

1. Buy 37% Formaldehyde which also contains 10-15% methanol as a stabilizer. Amazon sells it here & here.
2. Buy waterproof gloves and a face mask. To prevent your skin from coming into contact with it and to protect your lungs from the fumes.
3. Use a bucket or small aquarium to perform the 60 minute formalin bath. Temperature control the water by using a heater. It is very important to heavily aerate the bath for at least 30 minutes before and also during treatment to compensate for oxygen depletion. The fish should be placed in a premixed bath solution. DO NOT add more formalin after the fish is already in the bath.
4. Dosage for the bath is 1 ml per gallon, or 20 drops per gallon.

That should do it for Uronema (and Brooklynella). No further treatment required (for those two diseases!) Formalin will also eliminate any flukes (but not the eggs), and provide temporary relief for Velvet. Experimentation with using H2O2 to treat Uronema is ongoing, but efficacy hasn't been proven yet.

DO NOT use formalin (or H2O2 for that matter) on fish with open sores/wounds. It will burn them. This treatment is designed to treat fish who are carriers (light infestation) of Uronema. If you see active red sores on a chromis, humanely euthanize the animal: https://www.reef2reef.com/threads/how-to-euthanize-a-fish.266222/

If you have an aversion to using formalin, I would just avoid chromis altogether. It's not worth getting a free living parasite in your aquarium that going fallow will not eradicate. Uronema in high concentrations can affect ALL FISH; attacking the gills, viscera and body muscle.

There is anecdotal evidence (but never scientifically proven) that some fish exposed to formalin don’t live past 18-24 months. In some areas, the purchase of formalin is prohibited.

If you need confirmation of Uronema, take a skin scrape of the affected area and examine under a microscope. Compare to what you see below:

​

 

[BeltedCoyote]

Thanks @Humblefish

Don’t know if the average aquarist such as myself would find information like this if it weren’t for your efforts.

Great information. The process described is rather intimidating for the uninitiated to serious treatment methods. Looks like I’m avoiding damsels and chromis lol at least for now

 

[lagatbezan]

Thank you Humblefish! Great write up!
How long would you guess would be needed to successfully kill it with cp? is cp still a good option?

 

[Humblefish]

Thank you Humblefish! Great write up!
How long would you guess would be needed to successfully kill it with cp? is cp still a good option?

2 weeks in Chloroquine will usually get the job done, but a public aquarium recently ran across a strain that only formalin killed. Chromis were only saved by doing the above bath and then transferred into another tank. All other fish were successfully treated by dosing formalin daily for 2 weeks. (1 milliliter per 10 gallons is the in-tank dosage.)

This disease just isn't worth dicking around with anymore. Bring out the battle axe (formalin) or avoid chromis entirely!

 

[Big G]

Thank you again for your efforts to improve the hobby and save fish from disease. Humbled I am by your efforts.

 

[Humblefish]

Humbled I am by your efforts.

Thank you for doing such a great job in the fish disease forum.

 

[DavidJTawil]

Does this look like uronema?

appreciate it in advance for the help.

 

[lakai]

We should just stop making the use formalin so taboo and use it for all parasite QT.

 

[Flashy Fins]

@Humblefish I saw on another thread you mentioned 12 drops should be the limit in temps over 70. Wondering if this thread was overlooked in the update or if I should proceed with 20 drops?

I have a few anthias going through TTM now. If they make it to the end, the formalin I ordered should arrive around that time. Last time I had anthias, they all died of uronema in my QT. Wanting to avoid the same trouble again.

 

[Jay Hemdal Verified Community Expert]

@Humblefish I saw on another thread you mentioned 12 drops should be the limit in temps over 70. Wondering if this thread was overlooked in the update or if I should proceed with 20 drops?

I have a few anthias going through TTM now. If they make it to the end, the formalin I ordered should arrive around that time. Last time I had anthias, they all died of uronema in my QT. Wanting to avoid the same trouble again.

Hi, this is an old thread. Humblefish isn't active on this forum any longer, so you may not get a response.

I can update you with some additional information though. You are correct, TTM does nothing for Uronema. However, formalin baths only limit Uronema transfer between fish, it will NOT cure internal Uronema as these fish have. Once you see those skin lesions, the Uronema organism is already fully involved in the fish's muscles and internal organs, what the lesion is is literally "the tip of the iceberg". Formalin baths may kill the top layer of Uronema in the lesion, but cannot reach the ones lower down, and therefore the infection continues.

I avoid about 80% of Uronema cases by not purchasing green chromis, yellow coris or squampinnis anthias, and generally avoiding long supply chain fish from Indonesia and the Philippines.

Here is my article on Uronema. I wrote it when I was experimenting with chloroquine, but I have since abandoned that treatment for this disease. Please bear in mind that this was written when most people were misdiagnosing this as bacterial infections, back about a decade ago.

Uronema / Red Band Disease - Hemdal

Red Band Syndrome in Marine Fishes: Caused by the Protozoan; Uronema sp. Jay Hemdal Introduction: This moderately common disease of certain species of marine fish is so often misdiagnosed that most aquarists apply incorrect treatment methods...

www.reef2reef.com

Jay