Help I have a CRAB !!!

[Lilo]

This crab arrived with our live rock.
Does any body know what he is?

Is he a good guy or a bad guy!!!

This is the first time he has been seen in daylight, generally he hides in the rock and matches in very well.

 

[Omni2226]

From what I can see it has "pointy" claws which usaly isnt good.

A rule of thumb for crabs..."When in doubt off to the blender"

 

[Anonymous]

I do not trust crabs so I error on the cautious side. I would ditch it.

 

[Lilo]

Here is another image of the stowaway...
Are pointy claws bad then?

If they are how do I catch him?

It is difficult to see his claws but they are big compared to its body and legs. He is also camouflaged very well against the rocks.

 

[Omni2226]

Well if possible watch to see what rock it hides in then pull the rock and use neednose pliers/screwdriver/coathanger and yank it out of its hole.

You can try "fishtraps" get one of those plastic mousetraps that dont kill the mouse, bait it up with a bit of meat.

 

[Anonymous]

Put a glass jar on the substrate w/ some stinky food in it tonight. He will climb in the jar to get the food, and then not be able to get out.

Good luck!

 

[Meloco14]

In general, the hairy looking crabs with pointy claws can potentially cause problems. The claws indicate they are omnivorous and some will harm fish and other invertebrates. If they have comb-like claws they are generally filter feeders and relatively harmless. Having said that, I recently saw a crab similar to yours in my tank. He has to have been in there for 2 years and I've never had a problem, and never even noticed him. But to be safe I would take him out.

 

[Lilo]

Many thanks to you all...
I shall go crabbing tonight.

 

[tazdevil]

Do you have a sump with LR in it? That can be a good place for crabs, they won't harm livestock down there.

 

[Mihai]

They don't harm your fish and shrimps in the sump, but they *do* harm anything else you may have there (stars, worms, etc.). I had a bad crab (the one in my avatar) that wiped off everything in my fuge. It is still to fully recover even one year after its removal. If it was me - "to the blender". Or in my case to the LFS that gave me nice credit for it - it was a nice crab - for somebody that wanted a species tank that is.

M.

 

[PikachuSalad]

Have you caught that thing yet? I had a stupid crab that killed a dwarf lion fish several years back.

I've never tried this, but I've read several places that you can dip a piece of live rock (the one with the crab in it) in some extra salty water (1.035-1.040) for 30 seconds or a minute, which will cause all the inverts to crap their pants and evacuate the rock quickly, without harming the stuff you want on the rock.

You can then pick through the evacuees and put what you want back in your tank....as for the rest, I like Omni2226's idea

 

[Meloco14]

You can also just use freshwater, Pikachu. I had a mantis hiding in a rock so I used a turkey baster to squirt into all the holes until he came out. It worked perfectly. I don't know what would be less harmful though, freshwater or hypersaline water. Freshwater, obviously, is easier.

 

[Anonymous]

Actually you can use plain club soda to flush out any nasty that's hiding in a hole in a rock.

 

[Lilo]

We have caught him....
The little jam jar and prawn worked wonders. I would recommend this method.
He is back at the pet shop.

He did have pointy claws and they were very big compared to his body.

Many thanks to you all for the advice.