Im not sure about the emerald crabs. But the halloween crab probally molted. Crabs grow an shed there exoskeleton. It looks like a crab is laying there but it is just there skeleton. The crab usually remanins in the shell somewhat hid til his shell hardens up again to prevent injury or death. After they molt there body is very soft so that is why they hide I hope this helped some!!!
I have 2 Emerald crabs 1 is about 3 inches the other is about 11/2. I think they were mating the other morning. Is this possible?
Also, I had a Halloween crab die completely came out of the shell.The shell laid there about a week give or take. Then I looked and it looked liked the Halloween crab. I not for sure bacause I haven't seen his legs much but the one time I did see him crawling around his legs looked orange and black.
