Thanks for the pics!
We recently put another pair of emerald crabs in the tank (to take care of some bubble algae..algae undetectable now). We picked out a male and a female.
The first pair was a male and female by accident. I won't tell you what we thought when we saw them...well...having a good time together. We were fortunate to witness the female releasing her eggs some time later; I have a thread with pics somewhere around here.
Emerald crabs certainly have personality. One of the current ones, I think the female, thinks she is an acro crab; sleeping in the branches of the largest acro.
When moving around the tall rock, she often swings from outcrop to outcrop on one claw much like a monkey swinging through the trees.