Purple patch on clownfish

[cyarry]

Can someone help with my clownfish. My fish are currently in a QT. My clowns were fine, but today 1 of them seems to have purple patch in the white stripe by his head and have no idea why.

 

[Jay Hemdal]

Welcome to Reef2Reef!

That is a malady unique to clownfish, but we don't know the cause (yet). I've not seen it in any of my own fish, but I stated getting reports of it here a few years ago. I started a thread on it, but no real answers emerged:

Clownfish bruising/lesion?

All, Over the past year or so, I've come across about 10 cases on the fish disease forum here of an issue with clownfish that I have not been able to identify. I've never seen it on any clownfish I've had myself, but the issue seems most common on designer clowns, which I don't work with...

www.reef2reef.com

Jay

 

[cyarry]

Thanks. Just noticed that the other clown has it as well. All the fish are in the Qt being treated for flukes, which only the royal Gramma was suffering from. Related somehow?

 

[Sharkbait19]

Welcome to the forum!
I don’t think it would be flukes - though the issue does often seem to come secondary to another issue.

 

[vetteguy53081]

Thanks. Just noticed that the other clown has it as well. All the fish are in the Qt being treated for flukes, which only the royal Gramma was suffering from. Related somehow?

You said treated for flukes. What treatment are you using and how are you applying the treatment ( amount, number of days) ?

 

[cyarry]

My LFS recommended NT labs FMG for koi. It's a mixture of formaldehyde and malachite green. I dosed the recommended 1ml as it's a 40l Qt, leave for 5 days, then 50% water change and apply again

 

[Jay Hemdal]

My LFS recommended NT labs FMG for koi. It's a mixture of formaldehyde and malachite green. I dosed the recommended 1ml as it's a 40l Qt, leave for 5 days, then 50% water change and apply again

There is no indication that this is an external issue, you only see this on the white, less opaque portions of the fish, so that tells you it is an internal issue - that medication is only for external issues, and doesn’t work well on marine fish, so you should not follow that advice.
As the thread says, we don’t know the cause, but it goes away on its own in some cases.
Jay