swim bladder issue?

[Meshmez]

I have 4 lyretail anthias females in QT for 2 days now. they were all eating and swimming fine.
today one stopped eating, is looking pretty pale, and is swimming with its head high tail low. seems to mainly be using its pectoral fins. tail is somewhat closed up.

the other 3 still look great. any ideas on what might be going on and how to treat?

 

[Meshmez]

it is now just resting on the bottom, i noticed this mucus looking thing on its dorsal fin....