Asymptomatic diseased fish

[40lbBear]

Can a fish be an asymptomatic carrier of a disease, seemingly immune to its effects, while spreading to and killing others in the same tank?

 

[vetteguy53081]

Can a fish be an asymptomatic carrier of a disease, seemingly immune to its effects, while spreading to and killing others in the same tank?

While possible. A given fish is the host and once the parasite develops a life cycle. It reproduces and seeks other hosts who then contract the issue
Some aquatic life are resistant but rarely immune to disease

 

[Jay Hemdal Verified Community Expert]

Can a fish be an asymptomatic carrier of a disease, seemingly immune to its effects, while spreading to and killing others in the same tank?

That’s very rare. Most diseases that spread in a tanks are protozoans or worms. A fish may carry a disease like that for a time and not show symptoms - until stressed. The carrier is often the first fish to show symptoms and/or die.

Jay

 

[40lbBear]

That’s very rare. Most diseases that spread in a tanks are protozoans or worms. A fish may carry a disease like that for a time and not show symptoms - until stressed. The carrier is often the first fish to show symptoms and/or die.

Jay

so, no Typhoid Mary of the aquatic world?

 

[Jay Hemdal Verified Community Expert]

so, no Typhoid Mary of the aquatic world?

I can’t think of an example. The trouble is that home aquarists rely on visual symptoms only to diagnose diseases. If there was a Typhoid Mary, they’d never know it.
Jay

 

[40lbBear]

I can’t think of an example. The trouble is that home aquarists rely on visual symptoms only to diagnose diseases. If there was a Typhoid Mary, they’d never know it.
Jay

Appreciated. Thanks for humoring my question.

 

[Sharkbait19]

@Jay Hemdal
Could this occur with fish that are generally more resistant to disease due to thicker mucus coats? As an example, a clownfish bringing in ich but something like a hawk or tang succumbing first, or would the clown always show signs first making it identifiable as patient zero?

 

[LandLockedJones]

No expert, but I did see some somewhere there was some evidence of fish with thicker mucous coatings previously treated in low levels of copper long term (such as in lfs running copper) not showing physical signs of marine velvet. I will see if I can locate where I read this, as I am unsure of the validity of the source currently.

 

[40lbBear]

@Jay Hemdal
Could this occur with fish that are generally more resistant to disease due to thicker mucus coats? As an example, a clownfish bringing in ich but something like a hawk or tang succumbing first, or would the clown always show signs first making it identifiable as patient zero?

My situation: tank got wiped out, all except a long nose buttery. First two seemed reclusive following a cleaning, but not unusual for them. Dead within a day. Each looked like they had brook or velvet. I got the remaining into QT, each died within the week, similar pattern except no visible signs of disease like the first two. The LNB went through QT, tank was fallow for recommended periods. Introduced two new fish into a newly sterile QT with the LNB, and each are now dead. Reclusive, no signs of disease besides that. Water parameters are fine.

 

[Sharkbait19]

Did you get them into copper? Velvet is a fast killer, and by the time the characteristic white spots with velvet it is often too late.

 

[40lbBear]

Did you get them into copper? Velvet is a fast killer, and by the time the characteristic white spots with velvet it is often too late.

I had gotten them into copper

 

[Sharkbait19]

May have been too late then. Once velvet gets going, it often is too hard to stop.

 

[Jay Hemdal Verified Community Expert]

@Jay Hemdal
Could this occur with fish that are generally more resistant to disease due to thicker mucus coats? As an example, a clownfish bringing in ich but something like a hawk or tang succumbing first, or would the clown always show signs first making it identifiable as patient zero?

That's a good point - people have implicated mandarin gobies and moray eels in doing that, but I've never actually seen it myself.

Jay

 

[brwaldbaum]

This guy thinks he's dealt with a Typhoid Mary: