what kind of snail is this

[got bait?]

What kind of snail is this. I put 4 of these in my nano 5 mos ago and they are all still as healthy as ever. Don't want to mention how many turbos I've gone through since. Need to know the name so when I make a large clean up crew order from net, I know what they are.

 

[kreach]

Looks like a margarita snail to me... but I can't be positive...

 

[got bait?]

I bought some margarita snails and none look anything like these. These have a smooth shell and a distinct black spiral.

Thanks kreach