Diet

Although terrestrial snails have been documented with a wide variety of eating habits, the vast majority of them are herbivores – feeding mainly on plant material, lichens, and fungi (Dourson 2006). Polygyridae snails specifically are thought to search the leaf litter and consume microfungi found there (Auffenberg, Stange 1989). Besides consuming the leaves and stems of vegetation, they also enjoy eating fruits, wood, soft bark, and even algae (Klappenbach 2012).

Snails are frequently active at night or when moisture levels are high, and use chemical receptors on their tentacles to find food (Hotopp, Pearce, 2006). Once a suitable food source has been located, snails eat by rasping away small bits of food with their tongue (which is covered with chitinous teeth), known as a radula (Klappenbach 2012).

Besides plant material, snails also need a source of calcium to build and maintain their protective shells, which are secreted by the mantle (Klappenbach 2012). They get this mineral from a number of sources, such as from soft rocks like limestone or from the soil (Klappenbach 2012). In the case of soft rocks, they use their radula to rasp away small bits of limestone in order to get calcium (Klappenbach 2012). Also, a number of species obtain calcium by using their radula to glean it from empty snail shells (Dourson 2006).

Once ingested, food moves down the esophagus and enters the snail’s gastric pouch. Digestive juices in the esophagus give digestion a head-start, and food is further broken down in the gastric pouch via the attached digestive gland. The digestive gland then absorbs the digested material. The waste is passed on to the intestine, and is later excreted from the snail’s anus (Hotopp, Pearce 2006).