Catching a rogue crab

[likwid]

So I have had this rogue crab in my tank from the start (8 months ago). It is shaped like an emerald crab, and has a black body with hairy, light orange legs. He only comes out at night, and is extremely quick. As soon as he senses any movement from me inching up to the glass, he runs into a rock crevice and hides. He doesn't seen to be doing any damage in the tank. I have ever seen it nipping at corals, nor has it killed any of my livestock. I have seen him going to town on a clump of algae before though.

I caught a similar crab like this when I first set up my tank buy putting a little glass bowl in the tank, propped it up against a rock, and stuck an algae tablet inside. The next morning that crab was caught in the bowl and I was able to remove him. I was never able to get this one, and now with my tank populated with snails, hermits, and a cleaner shrimp, there is no way I can try this again. As soon as I put an algae tab in the glass bowl a snail gets to it, or my cleaner shrimp dives in, grabs it, and scurries away with it in his hands. Pretty funny to see actually.

Anyways, does anyone have any other ideas for catching a crab like this in a populated tank? Or, should I just leave him in there since he hasn't done any harm?

[The Codfather]

Hasn't done any damage.......yet. Don't leave him, sooner or later, he will start doing damage. I had a few unwilling to come quietly, patience was the key, try feeding a lot less frequently, sooner or later they have to come out to feed. I had to check in the middle of the night with a flashlight, but always seemed to catch them. Thanks,
Bob

[likwid]

Hasn't done any damage.......yet. Don't leave him, sooner or later, he will start doing damage. I had a few unwilling to come quietly, patience was the key, try feeding a lot less frequently, sooner or later they have to come out to feed. I had to check in the middle of the night with a flashlight, but always seemed to catch them. Thanks,
Bob

How do you catch them when they are feeding though? The only time I see him feeding, his body is almost completely hidden, and I can just see a claw reach out to pick stuff off the rock. Like I said, he is lightning quick, there is no way I can catch him without a trap of some sort.

[Newtoreef]

I heard if you cut off the bottom of a pop bottle bury the lid in the sand with the open bottom propt up on a rock, and zap strap some bait down in it in a media sock he will go in and not be able to get out.
I've also caught a huge rock crap out of my 140 gal with "the trap" and piece of prawn and some patience. I've caught another out of my smaller display by watching where his hiding spot is and take the whole rock out with him in it, then I fished him out of the rock with a coat hanger. not very pretty but got the job done, was tired of losing all my clean up crew to the little marauder.

[mandarin man]

when I started my RSM tank, there were many stone crabs in the live rocks. I tried to you jar and bait to lure them in, but it wasnot successful. Eventually, I spot and pick taking the live rock out knowing where it was. I managed to take them out one by one. It took me a couple of weeks to remove all of them. Stone crabs will eat and kill snails and hermit crabs...it is wise to take them out..

[The Codfather]

[QUOTE]How do you catch them when they are feeding though? The only time I see him feeding, his body is almost completely hidden, and I can just see a claw reach out to pick stuff off the rock. Like I said, he is lightning quick, there is no way I can catch him without a trap of some sort./QUOTE]

I caught the crabs using a large piece of shrimp tied to a rock. I would place it close to the glass away from the rock work, just after lights out. This way the shrimp could only eat so much, the fish would leave it alone, and after a few days of feeding light it was quite easy to catch the crabs in the open. The only problem was the waiting game, it took several nights, but i no longer have any. Thanks,
Bob

[Newtoreef]

Use his hiding spot as a trap he will dart into a hole then just take the whole rock he's hiding in. Worked for me on one occasion.

[likwid]

Thanks for the advice guys, it was very informative. I will try a few of those ideas and let you know.