I will try a thing. I caught many Theodoxus fluviatilis, a freshwater nerite common in Europa. It's the breeding season so they have already covered all sufaces with calceous capsules

List of freshwater snails compatible with opae ula conditions:
-Melanoïdes tuberculata (Mustafa)
-Tarebia granifera (Mustafa)
-Mieniplotia scabra (me)