Crab killed my cleaner shrimp!

[rauljra]

Green bluish crab came with live rock i purchased, i was told crab would not mess with anyone, but that was not case. what should i do?

[Avi]

I'd suggest that you get the crab out of your reef. I had serious problems with a Xanthid Crab that came in on live rock that I bought. I saw it when it was a small crab and didn't think much of it, and for well over a year it didn't do any damage at all that I was aware of. Then, I began to find zoanthids stripped down to the rock it was on in the mornings...it actually did this to all my zoanthids and mushrooms and then stripped acropora right down to the white skeleton. It isn't easy to get a crab out of a reef because they're very adept at hiding in crevices in the rockwork. I tried a number of methods but what wound up working for me was to put a shrimp (the frozen kind you get in the supermarket) into a container at night. It left it alone for a few days but then one day it started to take it out of the container. I actually used a trap and it managed to get the shrimp out but you can just as well use a jar like a peanut-butter jar or something like that. After some days it became bolder and bolder and eventually...after about two-weeks...it came for the shrimp even in the day-time, as soon as I put it into the tank. Then, when I was confident that it would take the shrimp as soon as I put it into the tank in the container, I was there with a net to prevent its escape and caught it in the jar. I was so disgusted with the crab for all the damage that it did that I thought I'd crush it but I didn't do that and put it into my sump, where it is...almost two years after I caught it. It can't do any damage down there. Sometimes I look back at photos I have of the beautiful coral that it destroyed and I just can't believe that I didn't crush it.