Should I kick out my Emerald Crab?

[dvb]

I have had an emerald crab (Mithrax sp) in my tank for about 6 months. When I got him he was very small and I had a little Valonia in my tank. The Valonia has been gone for a while now, and the crab is getting pretty big! Should I trap him and take him out? If his claws were outstretched, he would probably measure 3-3.5" across. In Delbeek and Sprung (vol1) they say that these guys are nuisances. Anyone agree, disagree?

 

[danmhippo]

I agree, but if he is not causing trouble (meaning nipping on your polyps, munching on corals...etc), let him be. Mithrax are pretty easy to catch if you decided you wouldn't want him in your tank in the future.

 

[dvb]

Any chance he could snatch one of my Percula clowns in the middle of the night? They don't have an anemone, they hang out in the hammer coral. Its pretty funny watching them rub up against it all night long when the coral is retracted.

 

[danmhippo]

Not very likely.....

 

[LilBugger225]

I've had emerald crabs that didn't hurt a thing (cept valonia) and I had a couple that were not quite as nice and decided to munch on corals. Never had one eat a fish though. Since I had one eat a huge chunk of my open brain (which quickly recovered but made me very mad) I have not kept crabs except hermits in my tank.

 

[XXX]

How do you catch one if need be?

 

[HistroHistro]

I wouldn't be to concerned about the crab taking the clowns either.

I have caught mithrax crabs with snap (box) traps and two liter bottles with inverted tops. Both baited.

 

[dvb]

I haven't tried it but I have read that you can bait a smooth glass or plastic cup and place it next to the rock wherever you have seen your crab. The crab will climb in and not be able to climb back up the smooth sides of the glass.

 

[Roach]

I have had one since it was a wee nip at the LFS. Over a year and a half later he's about 3" across and doing really well. I have never seen him mess with any of my corals or fish. He seems to be doing well on his own in there but if I see him mess with anything I might get rid of him.