Tons of little snails! From Nowhere!!!

[yearofthenick]

Hello,
Check this pic out. There are literally dozens of small snails all over my tank. I can only assume they come out at night since I NEVER see ANY during the day. I am shocked to have at least 50-60 little snails like these all over my 20g tank.
What's this all about? Who are these little buggers? Are they good or bad for the tank? Do they eat zoanthids?

 

[yearofthenick]

They don't have shells on their backs either. They do look like they have hardened backs though... kind of like a small turtle shell, but not. they're all over the glass and rock. What the heck?!?! Has anyone seen this before?

 

[yearofthenick]

Okay I did a little research and it looks like they're "Stomatella Varia" ... harmless snails supposedly. I am going to do more research on them and see what the dealio is.

 

[socalnano24]

I had lots of em in the first few months of my tank.... they get to be pretty large eventually. you are right, that they seem to have a "turtle shell" back. From what I know they eat algae and don't cause any problems.

 

[scopus tang]

Hard to tell from your picture, but if they are Stomatella, they are harmless to the tank and actually help out by eating algae. Nothing to be concerned about.
If they look like this (shell comes to a point), they are likely limpets;

Also beneficial to the tank.

 

[cranberry]

Out at night = stomatella.

 

[i<3reefs]

I've got one around the size of a quarter. They do get pretty big in snail terms.