Crab ID help please

[DangerDave]

So I noticed this guy in my tank. Anyone have an idea if it’s reef safe?

He appears to have a black shell, the shell itself is less than a half inch across, less than an inch in total.

Not the best pics because I needed to use a flash to get the pic. I don’t know how long it’s been in there or how it survived dipping. I started with dry rock.

Any help would be much appreciated.

Dave

 

[tdileo]

You have any SPS colonies? Might be an acro or poci crab. I’m no expert though.

 

[DangerDave]

No, aside from a couple tiny montipora frags I just got it’s all LPS or soft coral.

Dave

 

[DangerDave]

His right claw (from his prospective) is larger than the left.

 

[tdileo]

My next guess would be a black mithrax crab.

 

[DangerDave]

I was able to get a few more...

 

[DangerDave]

My next guess would be a black mithrax crab.

I think you’re right. I made a trap last night. He was heading for it, but backed off when the swarm of hermits came running. I’ll have to plan a diversion.

Dave

 

[S-t-r-e-t-c-h]

I think you’re right. I made a trap last night. He was heading for it, but backed off when the swarm of hermits came running. I’ll have to plan a diversion.

Dave

He might not be an issue. For all intents, it's going to behave like an emerald crab...

 

[DangerDave]

Stretch I agree. From what I've read today on them, it seems that it's really like everything else. Some bad actors, but maybe just fine. I'm still going to try the trap again. I'd like to get him into the frag tank. That would allow me to monitor it better, and get to it again if it needs to move to the sump.

Dave

 

[DangerDave]

Well it looks something took a chunk of my relatively new rainbow acan. I’m assuming it was the crab but I don’t really know. Regardless I want it out now, but I haven’t seen him in a couple days. The trap isn’t working, it gets worked by the hermit swarm and he bails.

 

[DangerDave]

Last night I saw him in my frag tank. He must of had a heck of a journey to get here. Anyway, here he is. Not sure what to do with him. Can’t see leaving him in the sump, he’s already went tank to tank via the sump.

 

[DangerDave]

After some more reading I think it’s a Xanthid. Off he goes.

 

[Sashaka]

Better safe than sorry. Glad you were able to catch him.

I have a red crab (not a strawberry)that I have not been able to id or catch. So far I don't think it's bothered anything, so I haven't torn the BioCube apart to catch it. I think mine might be what nyaquatic's calls a feeder crab. It has not been a problem, so far. http://www.nyaquatic.com/red-feeder-crabs-5-pc/

 

[Jose Mayo]

After some more reading I think it’s a Xanthid. Off he goes.

Yes, it looks like a Xanthidae crab, maybe Chlorodiella sp, like the one below:

It feeds mainly on algae, but, like all crabs, it is omnivorous.

Regards

 

[Rakie]

Who says you only have one?

I once had crabs on a rock. One day I saw a crab like 6 months after the tank had been up. Couldn't believe I had a 1/2" crab hiding in a 10g tank for half a year. Guess how surprised I was when I caught nearly a dozen of the suckers..

Keep watching. Your guy either went on the most epic journey ever, or you have more than one.