yesterday i was cleaning my tank, and my biggest trapdoor snail was above the water line after i siphoned. so i needed to move him back down. i gave him a little tug but he would not budge, so i tried again and he came off. i tried not to pull, but instead twist a little and sort of tickle his foot so that he would let go of the glass.

but i think i may have injured him and i'm really worried. basically, his foot will not close into his shell, and if i touch him or wiggle his foot he does not hide in his shell. i don't think he is dead because if i touch his antennae or other parts of him, they recede, but that is all that he does.

it has been about 16 hours now and he has not moved. now i know that snails can sometimes just sit around and do nothing for days at a time, iv'e seen it before. but i'm still worried due to the circumstances and i feel like i have possibly done something stupid. if he is injured, can he heal? and is there anything i can do? thank you.