Australian fresh water snails belong to the master group "Gastropoda" ( Snail) Gastropoda have a unique feeding structure called a "Radula" a special cartilage type structure lined with tiny teeth that the snail uses for rasping and scraping food from rocks etc. Freshwater snails have several methods of breathing underwater. Some have gills located within a mantle cavity inside the shell, others obtain oxygen from air filled spaces within their bodies and some have peripherally placed