Where do snail abbies come from?

[Leah]

Their mommies, only a guess

[Ron99]

Could be a stomatella snail. they have very small shells that do not completely cover them and they are very common hitchhikers. They will also reproduce without problem in your tank.

[raisemyrent]

I checked some pictures on google, that's exactly what he is!

thanks for the info, still a bit of a mystery how he got in there, must have been a dormant egg or something in a rock (months after I added the rocks, which had come from a well established tank)... but a good addition...