As in the experience of others, my small snails came in waves.

I had some interesting hitchhiking snails. Two in particular sat in one spot for weeks on end and I am wondering if they were a rock burrowing type, as they always seemed to create holes where they sat.

I don't understand why snails can't propagate and multiply in an aquarium.

In freshwater aquaria there are several different species of snail and all of them multiply rapidly, in fact a common FW problem is snails multiplying out of control.

If SW snails won't maintain self-sustaining populations in an aquarium you would have to ask why. Could the problem be not enough nutrients, lack of an essential element, a toxic water contaminant, or predation? And do people with refugia have snails propagating in them?

I have a number of cerith snails in my nano, and they have laid egges at least three times that I have noticed. The trouble is that I think either my shrimp or my hungry clownfish would nibble on them because they would be continously reduced. I have noticed a few baby cerith snails though (easy to notice from there characteristic shells) on occasion so I guess a few survived.

Rory

I think the problem starts with the fact that freshwater snails go directly from egg->snail. Most saltwater snails have a planktonic stage thrown in there to help dispersal. We all know how well planktonic stages do in a reef tank. When someone cracks the code we'll not only have tank bred snails, but also Centropyge angelfish and all that jazz.

Bert

I think making this assumption is a bit dangerous. There are thousands upon thousands of species of snail, many of which resemble one another. While what we are seeing may in fact be the young of our purchased snails, there is also the possibility that they are completely different species within seperate genera or families.

http://www.gastropods.com/Taxon_pages/Common_Names.html