What the #$#%@

[eddy]

Yesterday I had four percula clown fish. Today I have two, one would think that if they had died or been killed there would be some remnants in the tank. There is absolutely nothing to suggest they ever existed. I asked my wife if she they had died and she had removed them, she doesn't know anything about it. There are no fish big enough in the tank to have eaten them, and I checked all around the tank to see if they had some how jumped out. Nothing. The only thing I can think that may have possibly done anything is my arrow crab, however to eat two complete clown fish in one night, he would have had to explode. any ideas anyone.
Tank occupants are 2 remaining clowns, 1 tang, 1 royal granna, 1 arrow crab, 3 blue damsels and 1 golbie