Snail ID

[MarineFishGuy]

I have been finding these snails in increasing numbers in my Reef Tank.
I am not sure what they are.
Tonight I found two of them on Zooanthid polyps.
I have heard of predatory zooanthid snails, but I have not been able to determine if that is what these are.
They have similar markings, but lack the cone shaped operculum mentioned here.
http://www.reefs.org/hhfaq/snails/faq_heliacus.jpg/view?searchterm=snail

I found some larger ones and tonight saw two very small ones. They appear to be the same variety. Pictured below is a juvenile and an adult.
Any help would be greatly appreciated.

Juvenile

Adult
Thanks,
Ken

 

[Frick-n-Frags]

heh, all the snails in ID threads are looking like collonistas to me these days. and so do these.

the sundial snail(I had one) is a very flat shell and looks like something rolled up like how weatherstripping putty is rolled up.

this is more cone shaped, amd with the pretty pattern and the fact they are quite small......

 

[theop]

I agree that they are collonista snails. They are good algae grazers and are mainly nocturnal. Their population will grow to what their food supply can support.

 

[Frick-n-Frags]

I wouldn't mid having a collonista infestation one bit. I had some strombus cooking for a while, but they eventually fizzled out

 

[MarineFishGuy]

Thanks a lot, that looks like a better match to me too.

Collonista nanina appears to be the same, except the colors are brown instead of red for the markings.

These guys are anywhere from the size of a pin to the size of a pencil eraser.
Ken

 

[Frick-n-Frags]

maybe when you have a boatload of them, you would be willing to sell/swap a few.