Are these tiny/baby snails Good or Bad?

[muffe]

http://i44.*******.com/24e5mqe.jpg

http://i42.*******.com/2hzh0xu.jpg

http://i43.*******.com/2nc2dd2.jpg

Here's the list of known adult size snails I have in the tank currently.
Astrea
Nerite
Nassarius
Cerith

Are these offspring of a species above? Or a totaly different species? And are they beneficial, harmful, or neutral? :rolleyes: Thank you.

[Postal]

They are most likely collonista snails. They are a beneficial part of a CUC.

[muffe]

Thanks a million!

[daplatapus]

Good pics by the way.

[Sugar Magnolia]

Yep, collonistas. They will reproduce too.