Do McCosker’s flasher wrasse sleep in mucus coats?

[mochaclownlover]

Hello! I bought a McCosker’s Flasher wrasse and a yasha goby from my lfs last weekend. They are both currently in QT with full copper power dose. I saw some slime in with my wrasse where he’s sleeping and immediately thought it could be brook, despite showing zero symptoms. Then I thought I remembered that flasher wrasses sleep in mucus coats. Is this correct? or could this possibly be signs of early brook?
Sorry, not he’s not in the best spot to get a photo

 

[Crabby48]

Mucus coat

 

[mochaclownlover]

Thank you!