I got crabs

[mattmku]

I'm in the starting process of setting up what i hope to be a reef tank. Right now i have two damsels and 20 lbs of live rock. I placed most of the live rock in yesterday and I realized i have some hitchikers. I've taken care of a few of them but i still have one or two concerns. I have a small redish orange crab about the size of a half dollar and what i think could be a mantis shrimp. First of all, will these both be a threat to my fish and snails? Will a home made "pop bottle trap" with fresh shrimp in it work to catch both? Also, will my fish be attracted to the shrimp in the bottle?

Thanks
Matt

 

[lando]

A pic of the crab would be helpful. Anything with claws can pose a threat to a reef tank. I have a few dozen reef hermits in my tank with no problem. I would be hesitant of adding anything other then hermits. As for the mantis...you need to get rids of it or it will cause problems in the future. Figure out what rock it is hiding in and do a freshwater dip to get it out.

 

[mattmku]

I'm going to try to avoid tearing up my tank by having to dig for a bottom rock. Do the traps work?

 

[lando]

I have never had any experience with trapping crabs. But if you are going to try and get the mantis, now is the time. Before you add fish and other inverts.

 

[EL Diablo]

I am trying to catch a load of crabs in my tank,
Last night was the first night I set up a trap.
I used a wine glass with a fresh shrimp in it. tilted the glass against a rock.
I didnt catch any but will keep trying. Got to get rid of the Evil in the tank