Need help with this little crab thingy

From Lembeh, this little crab was found on a spine of fire urchin.

I have seen it a few times throughout SE Asia but could not find its name through my usual sources and books.

Thanks for any info.

The common crab on these anemones is Zebrda adamsii - but these are stripey so I don't think that this is what you have here.

I would guess (and I stress guess) that this might be a young swimming crab, rather than a urchin commensal.

I'll be interested to hear what others think.

Alex

Do you have any images of the back? That would be a big help in figuring out the name.

Hi

it's definitively not an eumedoniid (the family where Zebrida belongs to)

looks indeed like a small portunid (swimming crab)

maybe it's the sea urchin symbiont Lissocarcinus arkati

I found a photo of Lissocarcinus arkati from the web in my files, and post it here, maybe you'll recognize the crab

if not, it's just a juvenile free-living swimming crab who found a shelter among urchin spines

cheers

Art

Leslie, sorry, I don't have picture of the back of the crab. It was on an urchin in a middle of a big heaps of fire urchin so I only managed to get picture from one angle only .

Art, All that I remember was that it looked semi transparent and did not remember seeing any pattern or other coloration on the back at all. The back did not look like the picture of the Lissocarcinus arkati that you posted.