Orchid Dottyback not eating...

[lodidodi]

Hello,

I'm hoping someone could help me out. I've got an orchid dottyback that has just stopped eating. He still comes out but just doesn't eat any food. There's been no new additions for about a month and before the last couple of days. It's been eating just fine. Any ideas what could be causing the lack of appetite? Here's what I've got in the tank.

55g display w. 20g sump/refuge - 1x ocellaris clown, 1x 6 line wrasse, 1x blue damsel, 1x midas blenny, 1x orchid dottyback, 1x auriga butterfly, 2x skunk cleaner shrimp

Any help would be greatly appreciated. I love this fish.