bad crab

[Isernhagen]

I have a hithchhiker from the gulf of mexico on my live rock. He is a crab that is deep maroon or reddish black in color. He picks at everything except my corals. He eats barnacles for lunch. He has increased in size to 3 times his original size over the last 3 months. His body was about a nickle in size 3 months ago and now he is almost a silver dollar size. At first I said "look how cute he is with his interesting colors". He has the pincher tearing type claws. Now, I am afraid to add my small pair of black oscellaris clowns to the tank because I am afraid he will eat them. Currently, there are no fish in my tank. He has interesting movements side to side like a football halfback trying to fake out a tackle.
Does anyone know a good technique for catching him so I can transfer him to my sump for feeding rather than tearing everything up in my tank. Thanks.

 

[iamwhatiam52]

My best luck has been with leaning a jar against a rock near where the crab hangs out, and dropping a piece of food in after lights out.
The crab crawls in, but cannot climb up the smooth sides of the jar to get out.

 

[650-IS350]

It's probably a rock crab... bad news....