Missing Orange Shoulder tang???

I cannot find my orange shoulder tang anywhere! He's been in the tank about 4 days and I haven't seen him all day today. Usually he's swimming all over the place. I already checked behind the tank and he didn't jump. I've looked around in the live rock and he is nowhere to be found. He's about 3 inches. There is a small anemone in the tank that is about 6 inches when spread out. It's closed up right now and I'm afraid it ate him... Tank is 55 gallon. I know tank is too small for full-grown size, have a 125 getting set up in the spring. LFS has a 3 year old OS tang on display that is only about 9 inches so they said he'd do good in the 55 for a few months. Been eating mysis and nori great. Tank mates are 2 clowns, a bangaii cardinal and a tiger watchman goby. Water parameters are all right where they should be. Am I going to need to tear down the live rock in case he died in there? Or should I wait a few more days to see if he shows?

 

The LFS had him in quarantine for 3 weeks for me before I brought him home and he was very healthy, expect a little on the skinny side from being in the small QT tank with no algae to graze on. As for the anemone type it is a bubble tip. No cleaner shrimp right now. Emerald crabs, turbo snails and narcissus snails.

 

They get fed tonight, so hopefully he'll come out. I'll watch for him after the lights turn off in about an hour and a half. Hopefully he'll turn up.

 

There is no visible aiptasia in the tank. It's very possible he's just hidden really well, the goby has made an abundance of crevices he could fit it. I hope that is the case. Mike- I'll start keeping the nori out all the time if he does turn up.

 

I'm thinking he's a goner. Even the first day when he hid all day he darted out for food. No sign of him after feeding. That's what I've never liked about saltwater...40 dollar fish gone without a trace! Now just have to figure out what happened before I think about adding any other fish. Bye fishie :-(

 

Well, I think I found what killed him. I was just doing a water change and moved a piece of live rock and the side I couldn't see from the front of the tank is covered with aiptasia. The live rock happened to be the one he hid behind if he got spooked. Guess I'll have to get some peppermint shrimp to take care of it.