Where did you come from little guy??

Dsdaley77 · Oct 29, 2012

So I found this Crab in my tank and have no idea where it came from or what kind it is. It looks like an Emerald Crab but is ALL black with white stripes on his hairy legs. It also jumps around and uses it"s back legs like a spider would, Kinda creepy. Anyone know what it is??

returnofsid · Oct 29, 2012

The shape of the claws and hair on the legs definitely do make it appear to maybe be a Mithrax species crab. Those claws aren't built for catching fish or ripping apart corals. The claws are built for scraping algae. That doesn't mean it's reef safe though. Crabs are all opportunistic creatures. Keep a close eye on it and if you notice any corals being bothered, definitely be suspicious.

It probably came in as a hitchhiker, in live rock as a very small hitchhiker, usually on maricultured SPS colonies, if you've purchased any.

Dumnorix · Oct 29, 2012

Yeah I almost thought it was a Gorilla Crab until I looked more closely at the pinchers, great little bonus hitchhiker if he doesn't eat your coral.

OurReef · Oct 29, 2012

Might just be a color morph. I have a lavender emerald crab.

Dsdaley77 · Oct 29, 2012

It is so crazy how it moves, so fast. When I went back to view it some more, he took his back legs and folded them behind its back attached them to the Rick directly above and then did a little flip move to end up upside down. Weird

Thanks for the help with the possible id's, gives me a place to start my own search

Dsdaley77 · Oct 29, 2012

OurReef said:
Might just be a color morph. I have a lavender emerald crab.

He does look like my two Em's, one copper and one green, except for the stripes on its legs and the way it moves. I did get a 17 lb rock that came with the maxi in my albums and have lost a chromis, 4 of my turbo's and three blue leg hermits since then

(bout a month). I think it's time to try and catch this guy and sump him