HCA: Hermit Crab Association

I had posted about the hole in the claw the other day. Well I was doing my daily routine earlier, and I thought I would check up on that hermit crab. Hes been pretty much in the moss pit since I first saw the hole. Well when I picked him up to look at it, I saw this...I freaked out. Idk if I should put him in a iso tank or what to do. All of my other hermit crabs are perfectly ok. I have noticed this one seems to start fights with new crabs when I get them. Idk if he started another fight with a crab and it backfired on him. Or if its something else. If someone could please help though, I'm quite worried.

I actually have a crab with a similar BP injury. Mine was from an attack while molting, though. Have you noticed if it is a particular crab trying to get him?
Sometimes new crabs are super aggro before they molt. We have one little guy who is a jerk to everyone.
If you feel better about ISO'ng until it molts, then trying to introduce it back into the main tank, that would be okay.
If it continues to spread, it could be something else. Someone with shell rot experience can jump in here with any input because I haven't dealt with that yet.

Well he molted not long ago actually, so idk if I should Iso. But I haven't really seen any new crabs be aggressive. Only thing I've seen is this one will sometimes go up to the new ones and pushes them with his big claw. That's about all. I've never seen any major fighting, so I assume it had happened in the middle of the night. I worry for the damage to him. Idk who's doing it.

This was Sparky when I first got her. I did no treatment.





I can't find the after photos, but the missing piece took like four molts before it looked normal again.

Oh wow, well mine molted not that long ago, so not sure when he will again. But I'm definitely keeping a eye on him.