Identification
Land snails belong to the phylum Mollusca, the second-largest phylum in the animal kingdom. Within the phylum, snails belong to the class Gastropoda which typically possess: a well developed head bearing a mouth, tentacles & eyes; a visceral mass containing the reproductive & digestive organs, and a large foot with a creeping sole. Apart from a few exceptions most land snails belong to the order Pulmonata (gastropods which have developed a pulmonary cavity or lung). The shell of the snail houses and protects the soft parts of the animal.
Introduced Garden Snail, Cantareus aspersa
Photographer: Alan Henderson / Source: Museum Victoria
Distribution and habitat
Land snails occupy a variety of terrestrial habitats, including gardens, scrub, bush, rainforest and even desert. While native molluscs are still present in large numbers, the majority of molluscs species present in Victoria are introduced species. The distributions of most of the native snails are restricted to areas with native vegetation. In urban areas, the introduced species such as Cantareus aspersa (Common Garden Snail) are most frequently encountered.
Native carnivorous snail, Victaphanta atramentaria
Photographer / Source: Ross Field
Four species of native Victorian land snails, Allocharopa erskinensis, Geminoropa scindocataracta, Pernagera gatliffi and Victaphanta compacta are listed as threatened under the Flora and Fauna Guarantee Act.
Biology
Snails feed on a variety of foods. Many feed on living plants, and some on decaying vegetable matter. Others are carnivorous, choosing to eat other small invertebrates, such as insect larvae or other snails and slugs. Many of the introduced species of snails can be a serious pest in cultivated gardens, crops and pasture. Snails are hermaphrodite and are reciprocal fertilisers (that is, they can fertilise each other).
Escargot
Snails have long been used as a food by humans. The European edible snail Helix pomatia is a prohibited import into Australia, so the local industry must manage with the smaller species Cantareus aspersa, the common garden snail. Research has been undertaken to explore the culinary potential of large native species, but the results are inconclusive at this stage.
Further Reading
Barker, G. M. 1999. Naturalised Terrestrial Stylommatophora (Mollusca: Gastropoda). Fauna of New Zealand, volume 38. Whenua Press, New Zealand.
Beesley, P. L. et al. (eds) 1998. Mollusca, the Southern Synthesis. Fauna of Australia, volume 5. CSIRO Publishing, East Melbourne.
Smith, B. J. 1979. Field Guide to the Non-marine Molluscs of South-eastern Australia. ANU Press, Canberra.
Smith, B. J. 1992. Non-Marine Mollusca. In Houston, W. W. K. (ed.) Zoological Catalogue of Australia. Canberra: AGPS Vol. 8.