What is that?

[Jose Antonio]

Hi there,
My Chaetodon Collare, has as a "white sponge" in dorsal fin.
I don't know what is that, it eats without problem and hasn't other symptoms.
In the past (one years ago), I was a incident with Odinium, and my fishes dead..so I am very worried about that, because I have no idea how to proceed.
Chaetodon is a "newbie" member in my tank, was fighting with my other chaetodon at begin, but now, they are as "friends"

https://drive.google.com/file/d/1h0IuNRi9_PlShCGozad3TIW093aibcbK/view?usp=sharing

 

[James M]

That’s a sponge...filter feeder

 

[Jose Antonio]

That’s a sponge...filter feeder

sorry, a mistake, the last picture is a sponge of course ..."lapsus updatius"

 

[Muttley000]

Lymphocyst?

 

[Jose Antonio]

..i was thinking about it... common in that specie...
treatment?
any advice?
thank you in advance

 

[ncaldwell]

If it is Lymphocyst there is no real treating it other than making sure the fish has clean water, good food and low stress. The healthier the fish the better it can fight it on it's own. Had a copperband that had it and it want away on it's own after a month or so.

 

[GoldeneyeRet]

I agree it could be Lymphocystis

https://www.reef2reef.com/threads/lymphocystis.257461/

 

[Jose Antonio]

Thank you for your responses.
My fish looks fine. Eats (inclusive my zoanthus), but this spot is «ugly». Today ive seen it a bit more huge but outside its fins.as the spot goes to falldown...
I was thinking move the fish to QT, but..at this time after almost 1 week in principal tank....