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Marisa cornuarietis (Linnaeus, 1858)

Diagnostic features

Despite the species resemblance to planispiral planorbid snails it is nonetheless an ampullariid. Its large size, distinct spiral bands and the presence of an operculum distinguish this species from planorbid snails such as Planorbella duryi and Planorbis corneus.


Marisa cornuarietis (Linnaeus, 1858)

Common name: Giant Ramshorn Snail; Columbian Ramshorn Snail

Class Gastropoda

Subclass Caenogastropoda

Order Architaenioglossa

Superfamily Ampullaroidea

Family Ampullariidae

Genus Marisa Gray,1824 (Type species: Helix cornuarietis Linnaeus, 1758).

Original name: Helix Cornuarietis Linnaeus, 1758. Linnaeus,C. (1758). Systema Naturae per regna tria naturae, secundum classes, ordines, genera,species, cum characteribus, differentiis, synonymis, locis. Edito decimal, reformata. Tomus 1. Laurentii Salvii, Holmiae [=Stockholm], i-iv, 1-824pp.

Type locality: 'European Seas' (erroneous, probably Venezula).

Biology and ecology

On sediment and weeds etc. Lays pink coloured gelatinous egg masses on plants etc. below the waterline. Omnivorous and potentially a pest of aquatic crops.


Introduced from South America into the United States. Found in aquarium shops in Sydney, Brisbane and Melbourne.


This species is not established in Australia. However, it is commonly found in the aquarium trade and is a potentially capable of becoming established.

Further reading

Cowie, R. H. (2002). Apple Snails (Ampullariidae) as Agricultural Pests: their Biology, Impacts and Management. Pp. 145-192 in G. M. Barker. Molluscs as Crop Pests. Wallingford, UK, CAB International.

Cowie, R. H. & Thiengo, S. C. (2003). The Apple Snails of the Americas (Mollusca: Gastropoda: Ampullariidae: Asolene, Felipponea, Marisa, Pomacea, Pomella): A nomenclatural and type catalogue. Malacologia 45: 41-100.

Ferguson, F. F., & Palmer, J. R. (1958). Biological notes on Marisa cornuarietis, a predator of Australorbis glabratus, the snail intermediate host of schistosomiasis in Puerto Rico. American Journal of Tropical Medicine and Hygiene7(6), 640-642.

Horne, F. R., Arsuffi, T. L., & Neck, R. W. (1992). Recent introduction and potential botanical impact of the giant rams-horn snail, Marisa cornuarietis (Pilidae), in the Comal Springs ecosystem of central Texas. The Southwestern Naturalist37(2), 194-196.

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.

Perera, G. & Walls, J. G. (1996). Apple snails in the aquarium. T.F.H. Publications, Inc., Neptune City, New Jersey.

Simone, L. R. L., 2004. Comparative morphology and phylogeny of representatives of the superfamilies of architaenioglossans and the Annulariidae (Mollusca, Caenogastropoda). Arquivos do Museu National 62: 387-504.