I have three mexican turbo snails in my tank for about three months now. I noticed today that one of the snails has left its shell and there is no where else it could go there are no empty shells in the tank but i do have 35 lbs of rock on the tank. Where could have it gone? also on one of the better looking live rocks there are these little white cone shape looking things growing on it they start off small and mabey the biggest one is a 1/4 inch long there is about 15 of them are they good or bad?

ok first of all how many gallons is your tank? Do you have ANY other invertebrates, any other snails, shrimp, or crabs... especially crabs? Next, ive had a snail out of its shell for months now, see it all the time, jus goes around like any other snail, except without a shell, eating the algae off the glass, it is a turbo, not sure what kind though. And on your cone shaped things, do you have any pictures? Someone else on here might know exactly what it is but im not commin up with anything yet. closest thing i can think of are the astrea starfish, in which my tank has literally hundreds of those, kinda block the view. Note that invertebrates dont have an extremely long life span, ive lost probably 50 snails, prolly the same amount of crabs. There are things in your tank that you didnt put in there that will clean up things like that in the night.... lol and u think im kidding. No telling where your snail is at, especially if u only have 3...