Friend or Foe?

[ak_reefer]

Found this little guy in my live rock, just wondering if he would be safe to add to my tank.

Thanks,
Javier

 

[Krish]

Crabs are usually evil LOL!! I moved your thread to Leslie's forum just incase she may have a clue as to which species this is and if infact it is safe for your aquarium. I'd hold off adding him into the tank just incase it isn't a good idea.

 

[mfinn]

I've found too many crabs that turned out to be coral eaters.
I wouldn't trust it in my tank

 

[ak_reefer]

Thanks Krish, I am holding off on adding him.

 

[Chichas01]

to the sump with him!

 

[BReefed]

No, No, No! Don't sump that one!

It's a porcelain crab. Totally harmless, one of the only reef safe "crabs". I say "crabs" because it isn't really a crab at all, it only looks like one, it's a closer relative of a squat lobster. You can tell because despite them both being decopods, the Porcelinidae typically have six distinct rear legs, two mostly superficial front claws and inside of those two fan arms used for filter feeding. They also have the long antennae that your crabs have.

Hope you didn't exile this guy for the crimes of his cousins.

If you still don't want him, or trust him then I'll take him. I have a very friendly blue one in one of my tanks

 

[Herefishyfishy]

Unlike your porcelain "crab"

Appears his hitchhiker has 6 rear legs and lacks the long antenna, makes it a real crab

 

[BReefed]

Hey Mike,

My Porcelain crab actually has six walking legs as well, you just can't see them in this picture because they are tucked under his claws. This is kind of fuzzy, but it is the best I have since he likes to hide in dark places:



True crabs actually have four pairs of walking legs which are generally always visable:



I believe I also see the antennae crossing over the far right, second from the rear leg in AK Reefer's picture.

If it has eight walking legs then I agree 100%, it's probably to risky for anything other than a species tank. If it has six legs however, then it is a filter feeder that will spend most of its time waving its pereiopods almost like a feather duster once it settles in.

 

[ak_reefer]

Currently in my Fuge, hanging out.

 

[user 2204]

Watch it carefully. If you see those things near its mouth open up and the crab starts to use them as little nets to catch stuff in the water column, then it is most likely a member of the Porcellanidae family. Also if you look at the body and the way it is shaped similar to other Porcelain crab as well as the arms going to the pinchers. Very similar to the Porcelain crab.

Things to remeber is that there are 277 species porcelain crabs (Porcelain crab - Wikipedia, the free encyclopedia)

This website may assist in id's too:
crustacea.net - interactive keys