Catching unwanted hitchiker crabs

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Aquarium Advice Freak
Oct 18, 2004
I know this has been discussed before, but I am looking for a way to catch some unwanted crabs that I have in my LR. I do not want to do FW dips because of my corals and all the other "live" creatures on the rock. I would like to use something that I can lure them into while in the tank.

So far I have tried cutting the top off of a water bottle, inverting it and sticking it back in the bottle. I then put a piece of krill in the bottom and leave it overnight. I have done this a few nights in a row and all I do is continue to catch my hermit crabs. Obviously, these are not the crabs I am trying to get rid of. Does anyone have a better solution to getting a couple crabs out of my tank without removing the LR?


It seems to be alot more difficult to catch the crabs than anything else...for me at least. The bottle method has never worked for me. It was easier to catch the mantis shrimp, than the crabs. I hear the traps you can buy online work better than the bottle. My technique that works best for me is to rip the rock on top when they are on it. If the crab is bigger it can't go inside, other wise you have to dip. So that leaves you with buying a trap.
Here's what I did....I put a piece of shrimp into a fish net and lowered it to the place I last saw the crab ten minutes later, I pulled him out. I guess I got lucky.
I did the rock pull method too. I took the rock and put it in a bucket of salt/tank water. I used a rubber band to tie a piece of nori to a skewer (like for kebabs but a chopstick would probably also work). I used that to lure the crab out of the rock and then I flicked him off of the rock and took the rock back to my main. I offered the crabs up to my local reefkeepers club and have had at least 2 people show interest in giving these guys a good home. I'm waiting on grabbing the last one out before I send them packing. For now they're in my QT.
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