So I went on vacation for a week to visit some family and I get back today and my Emerald crab was laying in the sand dead. I noticed he was really pale and was hardly green at all so I poked him thinking he would spring back to his bully self and try and take my fingers out but he was stiff as can be. What could have caused this? I am not sure how long he had been dead because he was alive when I left so it had to have happened within the last week...