hitchhiking crab

[idgy]

How do I get rid of a crab the came on some live rock. He is took quick for me to get him with a net.

He was about the size of a dime 4 months ago when I setup the tank, now I want to add fish but I do not want him to eat them. His pinchers seem to have grown as well and look large. He is about the size of a quarter or maybe a bit smaller.

 

[Herefishyfishy]

What color and is there a black band across the eyes?

If a bad crab, about the only way to remove is by taking the rock out and suspend over container of tank water and hope he jumps in. If in a head of coral, usually need to crush a baddy

 

[MikeS]

I've had good luck using plastic coke bottle traps...another method I have used in the past is to find out where the crab is hiding, and cook him right in his cave using a turkey baster full of boiling water....

MikeS

 

[csdoyle]

I've caught a couple of crabs by clipping a piece of food they like into a large fish net and just waited and waited for them to crawl into or onto the net and then just pulled them out...

Chris

 

[idgy]

How do you know if it is a bad crab or a good crab?

 

[mfinn]

I have caught several crabs by putting a small wide mouth jar ( like a baby food jar ) in the bottom of the tank next to your live rock, with a weighted piece of shrimp in the bottom of the jar.
May take a few nights, but it should end up in the jar.

 

[Herefishyfishy]

How do you know if it is a bad crab or a good crab?

Ask Santa, he knows.

Need to get it identified first assuming that you haven't yet proof of predation. Please post a picture or a clear description.

 

[knowcrap]

There are like a jillion (or as quoted "about 42,000...") different crabs, personally if it's not a crab I put in the tank that crab has got to go. I have killed two, each time after noticing the crab (generally gnawing at an SPS colony) I would scan my tank each morning (when the lights are off) and once found I would take a skewer stick and jab at it...one took me a month and the other took me a few weeks.

There are a lot of sites with pages dedicated to crab ID, here is one to get you started: http://www.wetwebmedia.com/marine/inverts/arthropoda/crabs/swcrabs.htm

Good luck.

How do you know if it is a bad crab or a good crab?