I was just inspecting my tank this morning and I noticed that my sand conch has an eyeball missing, it is now just a 'stalk' with a dot on the end but the other 'stalk' has an eyeball like normal. This is odd because the fish in my tank dont pay any attention to the conch and there arent really...

this is my first time on the forum. I have a tiger sand conch and he was acting a little slow and sluggish yesterday. i woke up this morning and he pushed himself underneath my live rock and hasnt came out of his shell in about ten hours. Is this normal behavior or is he dead. any help is...