Viviparus
Here are pictures of Viviparus ater from northern Italy. We found the species in a quite nasty stinking, muddy roadside ditch close to the village Noale in the coastal plains. It is a very hardy species and maybe the best suited Viviparus for aquarium purpose. I keep a group of the stock in an aquarium with a winter temperature of about 8-12 degree, and the snails are active during most of the winter.
Read more