My crab got out of its shell underwater

[hermitsrus1966]

Ok soo this all just happened a month ago when I had got a teeny little pp from petco or pets mart ( I dont remember they r the same to me) anyhow not long after when I was giving fresh food I knocked him into the salt water dish. He fell on top of a large rock upside down. Now remember this guy has too big and too heavy of a shell on plus he is probably weak. He try to grasp something to get himself back upright and he can't he abandons his shell and goes nude underwater. I guided him onto a bamboo stick in the dish and took him out immediately put his old shell and others around him. He checked the first one out that he had seen and slipped into it. I am wondering why he did this? Is their something wrong with my crabitat or something?

[Crabby7Crabber]

Maybe it's possible he knew that the shell was too heavy for him, so he decided to "abandon ship" and leave his shell. It's a good thing you helped him with the shells, but I'm not surprised he went for the first one he saw. Shells are hermit crabs' homes. Their abdomens and body parts tucked into the shells need shells to be protected. Hermit crabs also curl up into shells when in danger (An example could be another animal attacking them, like a seagull). That's why on the beach you can find hermit crabs sporting crazy outfits, like a lego, to illustrate. Anything to keep them safe (I'm sure you already know this. I'm kind of just reminding myself just in case I were in a situation like this ). I don't think this scenario means there's something wrong with your crabitat. Just try to be a little more careful!