HELP, fish missing and coral dying...

[BigT]

I have a hitchhiker crab as well in my tank, and from what I have learned that they can prey of fish. None of my residents seem to be hurt or missing, but I am still trying to get the crab out with little success he only comes out far enough so I can see him but not get him. Does anyone know a technique to catch the crab, apart from tearing down my tank.