I have had four hermit crabs living in a terrarium together for about a year now. This morning, I found one of them outside of his shell, curled up dead.
I’ve heard that they can get whacked by other crabs when they venture outside of their shells. Is that probably what happened? The temperature in the cage is good, they have plenty of food and water, and their shell supply is plentiful.
Is it normal for a hermit crab to just drop dead like that? I’d hate to think that one of my crabs is a cold blooded killer, I didn’t raise him like that.
I’ve had pet hermies. He could have gotten in a fight, but I’ve had several die during difficult molts. It’s not uncommon. Was he digging a lot or was he buried in the sand/gravel for awhile before this happened? If so it may likely have been due to a molt. Molting is very stressful on hermies and some get so exhausted they die.
If you catch any more naked hermies, put them in a margarine container with their shell for a half hour and leave them alone. Usually they’ll go back into the shell. If that doesn’t work, you can try to GENTLY uncurl its abdoment a bit and ease it back into the shell. I did that a couple times with one little nudist I had and it worked. Their abdomens are very delicate and they need the shells not only for protection, but to store water to keep themselves hydrated. Without it they dehydrate very quickly.
Seriously, it’s impossible to ever know for sure. In my reef tanks I’ve seen one hermit jerk another out of his shell, inspect it, then haphazardly discard it for the poor bullied one to hope to reattain.
If the hermits were noticably agressive toward one another, enclosed together in a relatively small space, and one was molting, I’d hazard that it’s a good bet murder was behind it.
When they are ready to molt they’ll usually bury themselves completely in the sand, making a little cave out of moist sand to protect themselves while they shed, and then afterwards eat, their old skin. A surefire way to tell if he just molted would be if he looked more pale than usual. A newly molted crab needs time for their exoskeleton to thicken up and the new skin appears smoother and paler for awhile afterwards. Typically though, a molting crab may go under the sand and stay there anywhere from 2 weeks to a month, coming up periodically to take a little food and water. Had you not seen him for awhile? Other signs of impending molt are sluggishness and loss of interest in food. If none of these signs were present, it’s more likely that he either got in a fight, or left his shell to find another, and ended up staying out too long. Either way, sorry that you lost him. They are endearing little things aren’t they?
Do you have good humidity in your tank? Do you know whether your crabs are Equadorian or PPs? If you have Equadorians, they need salt water as well as fresh water access. If they are Equadorians, they will eventually die from lack of salt water, but this is a slow process as they store the nutrients and it takes a long time for them to die this way.
PPs are more colorful than Equadorians. The E crabs will be more of a pale tannish color than PPs. PPs are distinguished by their purple pinchers (hence PPs). PPs also have round eyes, while Es have more oval-shaped eyes. Es are also much more talkative.
All that being said, I think you probably just had a bad molt. It’s really common so don’t feel too badly about it. It’s especially common when you have too-low humidity in your tank so make sure you have good humidity!
