What is this growth on my praecox?

[Papasmerf73]

So I just saw this praecox today. Any ideas and how do I treat it? I had another praecox a few weeks ago that developed something under his lip that seems to have healed by itself although now under his mouth is all black. Both fish are active and eating. Thanks.

 

[A201]

Looks like a viral growth "Lymphocystis" to me. Not usually fatal, just ugly. It might eventually heal up on it's own.

 

[Blacksheep1]

I agree. Try upping your water changes and feeding some vitamin enhanced, quality foods to help give the best chance at recovery.