HCA: Hermit Crab Association

Hi - we have hermit crabs at my work as office pets. Another coworker did all the research to get the crabitat set up, so I don't have the specifics on what the substrate consists of, etc but she knows more what she's doing than I do. We had one presumably die and was disposed of. We had another do the same thing and in my research, I read a lot about how it is could be surface molting or something. These two both molted about a month ago and had both been active since. We've had them since July. After molting, they were lighter in color, to be expected. Within the last week, our second went limp partially out of his shell on top of the substrate. I'd been trying to watch for him smelling. Today, he had been isolated (presumed dead) and he is still limp, but seems to be more solid in his shell and he is a darker color than he had been. He does smell a bit fishy. I don't want to hold out hope if he's dead, or keep a dead crab in the crabitat for everyone, but I couldn't find anything about their exoskeleton color darkening once deceased. It's not black and he doesn't fall out of the shell. I welcome any ideas.

Crabs can do some unexpected things, but a classic surface molt progression leaves them limp only for a day or two at most right around when they go to shed their old exo. They'll start to darken and harden within a few hours of shedding but they should be alert and eating their old exoskeleton before their color comes back strongly. I'm sure there are crabs out there that take longer than this, and I've seen many people over the years describe the molting odor as being fishy, so it's never a clear cut answer without waiting and being sure. It is awful. I know. If you have doubts though it is safer to observe and be sure. If the crab slides from the shell or there's any sign of brown liquid in the shell then they have died.