Mycobacteriosis in Aquarium Fish

Stopping an outbreak of Fish TB using UV sterilizing filters instead of tearing tanks down and starting over. Managing mycobacteria rather than eradicating them. Scientific surveys on the presence of mycobacteria in the aquarium fish trade.

BettaCropJaw lesionLRMycobacteriosis in Aquarium Fish, a 15 page article, provides vital information that fish keepers can use to prevent—or deal with—“Fish TB.” Scientific surveys show that almost half of fish deaths due to unknown causes are due to mycobacteriosis. Article is based on the author’s experience fleshed out with the latest scientific research. Every fish keeper, whether professional fish breeder or beginning aquarium hobbyist, should read this.

Author: Diana Walstad

I'm a former science researcher that keeps aquariums and likes to write books.

6 thoughts on “Mycobacteriosis in Aquarium Fish”

    1. As I wrote in the article, an afflicted fish cannot be cured of Fish TB. Symptoms in guppies are emaciation, poor growth, and shrunken bellies. Good management (removing and destroying sickly fish, using a UV sterilizer) can keep it from spreading to other fish.

      Like

      Reply

  2. Hi

    Great article, thanks!

    Not sure if you’ll see this comment or not, I was just wondering if in your research ‘sunken belly’ has frequently been associated with MB. I see it referenced a lot online, but other than one mention of emaciation I don’t see it talked about your article or in the research papers I’ve looked through much.

    I have an electric blue acara that developed a sunken belly after an ich infection. It was a fish I had just bought and showed ich symptoms about a week later. After the ich cleared up and I noticed the sunken belly I medicated for parasites (levamisole, metro flakes and general cure) but saw no improvement, there are 6 turqoise rainbowfish and 2 angels all bought around the same time who are all doing fine.

    It’s been about 2 months now and there’s been no change. Belly is still sunken but he’s eating/acting fine and poop looks fine. My only thought left would be fish TB, I can’t quarantine because I don’t have a big enough tank and I assume by now the other fish have whatever he has (if anything), I added a UV filter last week to hopefully keep anything from spreading but I’m really not sure what to do

    Like

    Reply

    1. We may be just parsing words here. Primary symptom of mycobacteriosis is emaciation, which would include sunken belly. While fish with sunken bellies can live a fair amount of time, I’ve never seen a fish recover from a sunken belly. Also, you’ve got Rainbowfish, which seem to be more susceptible than other fish to MB. In this situation, I would discard the blue acara. (You have nothing to gain by keeping him, and everything to lose.) It is quite possible that with the UV sterilizer, the other fish will be fine. Even if some of your other fish do develop symptoms, they will be less likely to spread it to uninfected tankmates with the UV sterilizer. It is good that you have been so careful. Good luck!

      Like

      Reply

      1. Thank you so much for the reply, I think I was just holding out hope that it was something else other than MB and I was trying to fit the research to the results I wanted. Since then I’ve found several other posts online with electric blue acaras that look just like mine with the sunken belly, one took the dead specimen to a vet who confirmed fish TB. If the shoe fits…

        I don’t have the heart to euthanize Blub, this morning I bought him a $30 29 gallon tank on craigslist as his hospice home. It’s already been a couple months with no behavior/appetite changes so I figure he might possibly be around a few more months. I got a separate siphon/net/bucket etc to avoid any cross contam, let him live out his last days in peace. Since he’s still a juvenile and unlikely to grow the 29g should be a good amount of space, I plan to euthanize when behavior changes or he loses his appetite

        I’m going to wait and see what happens with the other fish in the tank. I have 13 other juvenile rainbows in a 55g that were waiting to go to the (likely infected) 90g before illness hit, I’ll probably wait a couple months with the UV going and make sure no other symptoms pop up before making the switch. This hoppy really is a good lesson in patience

        Thanks again! Just bought your book 🙂

        Liked by 1 person

  3. Thanks for feedback. Since your Acara (‘Blub’) is still alive, the mycobacteria involved are not that virulent. Combined with your efforts and new knowledge, the prognosis for your managing this disease, IMHO, is promising. I don’t think there’s any way to eradicate mycobacteria, as they are a natural part of any established aquarium. The trick is to stay on top of things–as you are doing. Bravo!

    Like

    Reply

Leave a comment