blackspots

Can anybody tell me what’s up with my powder blue? All other fish are fine. No corals in this tank. He seems to be swimming sideways but only sometimes. He’s also swimming perfectly straight when he wants to so I don’t think it’s his swim bladder. He also has these dark spots (see pictures) on...

Hey all!! my two clowns (perculas I believe?) have recently developed these black spots on them, that my partner noticed. I’ve had them for over a year now, and they had these black spots once before maybe 8 months ago? when they were trying to host an elegance, but I haven’t seen the dots...