please help me Id this!!!

Hi all i woke up this morning and saw tow big brown spots on one side of my lemon peal tang i have this fish for about 3 months im sure that he was fine yesterday! the only thing that changed in my tank is that i added a small clown tang, he is still eating but not with the same energy like before please help me id what this is it dos not look like a parasite and if anyone have any ideas on how to treat him. Thanks and its comforting to know that we have a to whom to go with any concern.

 

I can not see anything with enough detail to make an ID, looks at Flukes of Marine Angels and see if they looks or sounds familiar. Odd another member here described these brown spots on his fish almost exactly the same way.

 

dos fluk come out so fast just overnight and in only tow big spots?

 

Do the spots look like tissue inflammation or redness/sores? Or does it look like something over laying the skin?

 

its looks more like over laying the skin.