Thats it ive lost my mind! (again)

[Grug]

PLEASE HELP ME!
i have a brand new tank setup.. cycled over 4 weeks.. all was well.. (barring the aptasia problem)

Put a snail, Hermit crab and blue tang in tank last weekend.

come home from work today and my heart sank.. my hermit crab had left his shell and died. something had been chewing on him so i got him out quick smart and as i was wondering weather to get the shell out as well.. IT WALKED AWAY!?

where on earth did this shell less hermit crab come from???!!! could there have been siamise twin hermit crabs in one shell?? do they shed whole bodies??? please help me i think im going insane!!!!!

I know that the body i took out of the tank had eyes feelers and all legs .. that much i could see.. i also noticed that the one that walked away from me had both his claws where on sunday night i noticed that one was missing/much smaller than the other.. jelly like..


also.. upon furthur inspection.. my rather sizeable snail is gone.. shells there.. meaty bit missing.. aliens?

 

[Grug]

its ok.. i think ive solved it.. hermit crab moulted.. didnt know they did that.. now i do..
snail still a mystery.

 

[Krypt]

Chances are the hermit crab ate the snail for his shell. Hermits will do that if you don't have a couple extra shells laying around for them to move into as they get bigger.

Oh and I would seriously consider taking the blue tang back. Blue tangs need a 6ft long tank to remain stress free and have a long life span. Even if it's a juvenile and only 1 inch long, still needs the swim space.