My newest discus

[plebian]

I recently purchased a group of 5 yellow discus. Unfortunately, 2 of them died from what is sometimes called "whirling disease" or "mad discus disease". The actual cause of this disease is unknown, though there are lots of unsubstantiated theories. I personally believe it's a nervous disorder of genetic origin. Over the years, I've had 5 discus die from it.

In any case, I've attached a photo of the 3 that remain. They are approximately 6 months old. The one on the left is the tank boss, a male. The one in the middle is his female partner. They are too young to spawn, but are already engaging in pre-spawning behavior. The one on the right I think is also female. I believe she isn't happy with the current arrangement and is trying to drive off the other female, who is having none of it. You can see the two of them facing off just before engaging in a round of mouth-fighting. I've been through this before with females, though they were part of a larger group.

 

[Colin_T]

What are the symptoms of whirling disease?
If the fish spin/ spiral out of control and die a few days later, it's an infection in the brain and usually caused by protozoa, bacteria or a virus (protozoa being the most common cause). It's usually associated with a dirty tank (including gravel and filter). You can normally stop it spreading to other fish by cleaning the tank up and adding salt, but the affected fish that is spinning does not recover and dies.

 

[plebian]

What are the symptoms of whirling disease?
If the fish spin/ spiral out of control and die a few days later, it's an infection in the brain and usually caused by protozoa, bacteria or a virus (protozoa being the most common cause). It's usually associated with a dirty tank (including gravel and filter). You can normally stop it spreading to other fish by cleaning the tank up and adding salt, but the affected fish that is spinning does not recover and dies.

That's one of several unsubstantiated hypotheses. On a related note, the disease is often reported as occurring in established, bare bottom tanks with daily water changes. Somewhat ironically, some have concluded it was caused by the frequent water changes.

 

[Colin_T]

I doubt regular water changes would cause it unless the new water was contaminated by something.

The problem with discus is most people feed them a meat based diet and that doesn't agree with them. And meat foods cause water quality issues much faster than plant based or dry foods, and the meat encourages harmful protozoa and bacteria to grow.

 

[GaryE]

There are microscopic parasites that cause a spinning disease in farmed trout and salmon up here. The water conditions are radically different, as are temperatures, but serious research has been done since it has an economic impact.

All we need is a few more tens of million Discus farm customers, and the problems will be studied.

I believe the northern parasite needs tubifex worms as an intermediate.