Help ID'ing a crab

[vic622]

So I tried the baited shot-glass trick last night, using a 3" tall tumbler with a 2" mouth.
Put some frozen clam meat that I had left over from making my homemade frozen reef gruel - all good, until the Half-yellow Blue Damsels smelled it.
5-mins, empty tumbler, smug Damsels
Plan-B: cover 1/2 the mouth with Saranwrap.
More News, tomorrow.

Vic