Crab ID Help!

[wildkats]

I discovered this guy today hanging out on one of my sponges. I'm guessing he hitchhiked in my cabbage sponge, and because of his coloring I never noticed him. Could someone please tell me what he is, and if he's reef safe?

Thank you

 

[mhills16]

wow that thing is pretty cool, judging by the way he blends in with the sponge id make a guess that is what he feeds on maybe...

 

[JackKerouac]

Never seen before,but it looks absolutly cool!Take a look to your sponge if you see some pieces missing,but it could be that's only a mimic color to protect himself by predators......
It's so cool looking that I would keep him anyway

 

[billyWhite]

It's a Red Decorator Crab. I think they pick stuff up and put them on their back, like sponges or Zoas and stuff like that. He might take a little chunk out of your sponge to put on his back, but I don't think he'll obliterate it.

You Tube Video: http://www.youtube.com/watch?v=MUfGnGNlIJc

 

[JackKerouac]

nice video

 

[wildkats]

Thank you for the ID help. Since I've taken the picture 2 days ago, he's placed some algae and other misc. things all over his body. It does seem that he places them strategically so that he will blend in with his surroundings.

Thanks again.

 

[wildkats]

Just out of curiuosity, does anyone know how big he will get because he's already about 1 1/4" across the widest part of his back?

 

[billyWhite]

I'm not 100% sure, but I think they stay pretty small. I can't imagine he'll get much bigger, if any

 

[LeslieH]

Size depends on the species. Many of the tropical ones stay small. On the other hand giant spider crabs & king crabs are also decorators as juveniles but they're not exactly species you need to worry about in a reef!