question about aquarium snail?

Hi... i set up an aquarium earlier this month. This is the first aquarium i've had in a long while, and i have a question about a snail someone bought for me.

The snail has a yellow shell, and i'm not sure of the name of it, since i wasn't the one who purchased it. The snail's shell is about 1/2" from tip to tip.

When i got the snail, i put it carefully into the aquarium on one of my plants. It seemed to just sit there for two days, doing nothing.

This morning, i see the snail's shell laying on the bottom of the aquarium, and the animal is gone... shell is empty!

I am perplexed over what happened to the animal. I have several fish in my aquarium, almost all of them are youngsters. These are the types:

2 angel fish, about 1-1/2" from mouth to end of tail

3 green tiger barbs, youngsters

3 cory cats (one is an adult, good sized, the other two are juveniles)

3 guppies

1 algae eater

1 platy

Is it possible that my fish ate the snail?

thanks for your responses.