Crab ID - Peaceful?

[timfederwitz]

Found this guy in my package of sand from TBS. He's pretty big, so definitely don't want to add him if he would take out my CUC, etc., but he is cool looking.

Doesn't look like a Gorilla Crab to me, but the claws seem rather pointy.

Can anyone ID it?

 

[jraker]

doesnt look like anything ive seen before. throw it in the refugium just to be safe until someone can correctly ID it.

did you notice the pistol shrimp next to the crab? i know i just did. throw it in the refugium also. if you hear snapping, that means it is alive.

 

[timfederwitz]

Richard from TBS said it's a Mithrax, AKA Emrald Crab. I put it in the tank for now.

 

[BigJohnny]

That's not an emerald crab, the claw/claw arms are too skinny. It also looks striped

 

[Sugar Magnolia]

Looks like a mithrax to me.

 

[ShaunMonahan]

There are many species of mithrax (Mithraculus) crabs and this looks like one. I would remove it just to be on the safe rather than sorry side.

 

[cmanning317]

I have red and green emeralds. ..that is not one

 

[timfederwitz]

Well, I moved him to the sump for now. He was very active and seemed to be going through things and even eating barnacles. He VERY cool looking, and fun to watch, but I saw him grab a snail shell and dig in it, and I figured he might eat my snails (it was an empty shell).

I took some video of him and will try to post them and link to it here, but I'm thinking I may not want to test him once I get my CUC and other livestock. He's sizable for sure. His body is probably the size of a half-dollar coin around.

 

[timfederwitz]

Here's a video of him in action. Does this help with ID? Seemed like he would eat all my barnacle in a week if I left him in.
https://vimeo.com/138928463

 

[DingDong128]

Cool video. Kids are great. Thanks for sharing.

 

[g_langley]

I'm pretty sure I have two of these which came as Hitchers. I've only seen brief glimpses but the claws and arms are much the same as your picture/video. Would be interested for ID confirmation myself.

 

[Shawn O]

With the number of people buying from TBS it would be of good value to know the safety of this crab. If you were inclined to do so, you could put him in a fish bowl with a snail, a hermit, a small bottom-dwelling fish and a small coral frag. If he eats any of them in a day or two we'll know his preferences.

 

[Betta132]

I'd suggest putting him in a refugium or sump, if possible, especially since we know he's willing to eat sessile inverts. Keep him well-fed, and let's see what he grows into! He might develop more recognizable features once he grows a bit more. Right now, he just kind of looks like a mix of a spider crab and a mithrax crab. His claws look a bit too skinny to go after fish, though that might change once he grows.
The tiny snapping/pistol shrimp next to it is harmless. Pistols can't kill anything more durable than worms, and that looks like one of the teeny transparent pistol species that won't get much bigger than that. At worst, he'll eat a few tiny worms.