Large sinistral, biconcave shell, whorls rounded and spire sunken. Umbilicus very wide. Animal brown or red with thin tentacles.It differs from the similar Planorbella duryi in having more rounded whorls and lacking the distinct mantle mottling of that species.
Planorbarius corneus (Linnaeus, 1758)
Common name: Ram's horn snail.
Class Gastropoda
Infraclass Heterobranchia
Megaorder Hygrophila
Order Lymnaeida
Superfamily Planorboidea
Family Planorbidae
Subfamily: Planorbinae
Genus Planorbarius Duméril, 1806 (Type species: Helix corneus, Linnaeus, 1758) (Synonym Coretus, Gray, 1847).
Original name: Helix corneus Linnaeus, 1758. In Linnaeus, C. (1758). Systema Naturae, per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata. Holmiae : Laurentii Salvii Tom. 1-824 pp.
Type locality: Northern Europe.
Synonym: Planorbis adelosius Bourguignat, 1859
On water weeds etc. in ponds. Feed on algae and detritus. Egg mass an elongate capsule containing 12-40 small eggs. Development direct.
Introduced from Europe, common in aquariums but not established (to our knowledge) in the wild in mainland Australia but in ponds in urban areas in Tasmania (Launceston) and at least one plant nursery in Melbourne.
Native distribution Western Europe to Siberia and the Middle East.
This large, red-coloured species is sometimes encountered in the aquarium trade. It has gone by the name of Planorbis corneus for many years.
Albrecht, C., Kuhn, K. & Streit, B. (2007). A molecular phylogeny of Planorboidea (Gastropoda, Pulmonata): insights from enhanced taxon sampling. Zoologica Scripta 36: 27-39.
Albrecht, C., Stelbrink, B. & Clewing, C. (2019). Planorbidae Rafinesque, 1815. Pp. 181-186 in C. Lydeard & Cummings, K. S. Freshwater Mollusks of the World: a Distribution Atlas. Baltimore, John Hopkins University Press.
Baker, F. C. (1945). The molluscan family Planorbidae. Urbana USA, University of Illinois Press.
Kershaw, R. C. (1991). Snail and Slug Pests of Tasmania, Queen Victoria Museum and Art Gallery.
Ng, T.H., Tan, S.K., Wong, W.H., Meier, R., Chan, S-Y., Tan, H.H. and Yeo, D.C.J. 2016. Molluscs for Sale: Assessment of Freshwater Gastropods and Bivalves in the Ornamental Pet Trade. PLOS One. DOI:10.1371/journal.pone.0161130.
Smith, B. J. and Kershaw, R. C. (1979). Field guide to the non-marine molluscs of south eastern Australia. Australian National University Press, Canberra, Australia.
Smith, B. J. & Kershaw, R. C. (1981). Tasmanian Land and Freshwater Molluscs. Hobart, University of Tasmania.
