Assume this is a crab, but what kind???

[WetLens]

Shot these photos during a recent trip to the Bahamas. Both photos were shot on a night dive - Two Grouper Reef off Conception Island in about 25' of water. The crab(?) was under a flat shell on top of a boulder. I lifted off the shell to see what was moving (I know...). The inset photo is the crab(?) in my wife's hand to give size perspective. Trying hard not to further harass the animal, these are the best shots I could muster. Any ideas?

 

[Sully3]

was it alive.
it looks like an empty carapace

 

[WetLens]

Yes, it was alive. It moved on the rock before I picked it up and placed in my wife's hand. We shot a quick photo and placed it back in the general area and it moved for cover. I had hoped for a better angle, but it ended up in a crevice.

 

[UnderwaterBumbleBee]

I think it's a decorator crab. We saw several in the Bahamas as well, they like to cling to sea fans and blend in pretty well. Here's a shot of one I took on a night dive. http://travel.webshots.com/photo/2700116270037104772tgeLnX

 

[WetLens]

Your photo is of a Neck Crab - this definitely was not a neck crab. The width between the eyes is significantly greater. I'll work on a closer crop of the photo.

 

[Sully3]

it may just be a crab that has a scientific name somewhere,
but there aer so many little crabs and shrimp like that in the
caribbean it could be anything.

 

[WetLens]

I cropped the photo at full resolution, then reduced by 50% to keep file size down. Also attached a photo of a neck crab from the same trip to show why I do not believe it is the same creature. I've taken lots of crab pictures... never seen anything like this.

 

[Sully3]

send it too Les Wilk from Reefnet.
He should be able to find out what it is
its definitely not a neck crab. neck crabs are pretty distinctive
matt

 

[WetLens]

"Hi Frank;

I showed the photos to a crab specialist. Here's the reply:

"From the relative lengths of the walking legs and their end joints, the frontal teeth and shape of the carapace, it looks like a juvenile of Ethusa mascarone americana."

Les"
Les Wilk

Common Name: stalkeye sumo crab per ITIS Standard Report