Angel Fish are disappearing!

[Tikibar]

I have had at least 4 angelfish disappear with no body, bones, anything! Today my majestic is missing... I don't think I have a mantis shrimp as normally you hear their popping noises. They are not jumping out. I have checked every time. I have looked as best I can between the rocks everywhere! Is there something that could drag them under the gravel? So tired of losing expensive fish. Tank parameters are fine. All smaller fish and corals growing great. Even Tridacna clams. Help?!?

 

[JTP424]

Hmmm....
Concerning...
Can you post your parameters, photos of the tank, a run down of your tank timeline etc?
TELL US MORE!!!! :)