Viviparus georgianus, common name the banded mystery snail, is a species of large freshwater snail with gills and an operculum, an aquatic gastropod mollusk in the family Viviparidae.

This snail is native to North America. The specific epithet georgianus is a reference to the southern State of Georgia, where the type locality is situated.

Original description

Viviparus georgianus was originally discovered and described (under the name Paludina georgiana) by Isaac Lea in 1834.

Lea's original text (the type description) reads as follows:

Shell description

Viviparus georgianus has a relatively globose, dextral shell, with 4–5 whorls separated by distinct sutures. The outer lip of the shell is quite thin and the overall coloration is yellow-green. There are abundant rows of hairs with distinctly hooked ends and ridges on the periostracum. The umbilicus is narrow or not apparent, and the operculum is round to oval, with concentric circular markings that radiate from an off-centre origin located towards the top left.

There are always 4 darkly pigmented bands that wrap around the shell spirally, but these are sometimes only visible from the inside of the shell.

One-year old snails are 12–17 mm high; at 2 years, 17–21 mm high; and at 3 years, 21–30 mm high. The maximum height is 45 mm.

Ecology

Habitat

This snail is found in lakes and slow-moving rivers with mud bottoms. The species thrives in eutrophic lentic environments such as lakes, ponds and some low-flow streams. It is usually absent from larger, faster flowing rivers; however, it is able to survive conditions of high water velocity in the St. Lawrence River, and in the United States it may even be better adapted than the introduced species Bithynia tentaculata to such habitats.

Individuals are generally found in a range of habitats, including: regions with silt and mud substrate; communities dominated by diatoms and filamentous algae (not blue-green algae); shallow waters with sand or gravel substrate; soft and hard water; water with pH between 6.3 and 8.5; freshwater habitats only; river reaches more than meanders.

Viviparus georgianus breeds and lives in shallow waters, often amongst macrophytes, in spring to fall, then moves out to deeper areas in the fall in order to overwinter away from shore. In more open waters, fall migration begins earlier than in smaller lakes and ponds. Most growth generally occurs when waters become warmer in spring and summer, although reduced growth continues in winter.

Life cycle

It is dioecious (it has two distinct sexes), iteroparous (reproducing more than once in a lifetime) and ovoviviparous, laying eggs singly in albumen-filled capsules. Females generally brood eggs for 9–10 months. Fecundity is generally between 4 and 81 young per female, but on average is closer to 11 young/female. Females can brood more than one batch of young at a time, and the number of young in one brood is positively related to the size of the female. Reproductive females are usually larger than 16 mm. Female banded mystery snails live 28 – 48 and males live 18 – 36 months.

Feeding habits

Viviparus georgianus is known to be a facultative or even obligate filter-feeding detritivore. Because of this, it can be used as a bioindicator of sediment contamination by oil and fertilizer, because its growth, survival and histology are significantly affected by the ingestion of contaminated sediments.

This species grazes on diatom clusters found on silt and mud substrates, but it may also require the ingestion of some grit, in order to be able to break down algae.

The banded mystery snail often lives at high densities, sometimes up to around 864/m².

Parasites

This snail is host to many parasites in its native habitat, including cercaria, metacercaria, ciliated protozoans, annelids, and chironomid larvae.

Distribution

Indigenous distribution

The banded mystery snail is native to North America, generally found from the northeastern United States to Florida and the Gulf of Mexico primarily in south central Florida, Georgia, Alabama and north, mainly in the Mississippi River system, to Illinois and northwestern Indiana. Massachusetts, Indiana and Connecticut are probably some of the states marking the northern limit of this species’ native range.

A recent study found that Viviparus georgianus is in fact not one species, but a species complex in North America. It was determined that Viviparus limi is native to the Ochlockonee River and southwestern Georgia, while Viviparus goodrichi lives in the Florida panhandle and southwestern Georgia, and Viviparus georgianus defined sensu stricto is found in eastern and southern Florida as well as the Altamaha River in Georgia.

Other populations in the Altamaha, Mississippi and St. Lawrence River basins have not been studied yet with respect to their specific genetic make-up, and so they are simply named as being part of the Viviparus georgianus species complex.

Nonindigenous distribution

This species has invaded the northern part of the United States: Ohio, Michigan, Wisconsin, Virginia, Pennsylvania, New York, New Jersey, New England, as well as Quebec and Ontario in Canada.

In the Mid-Atlantic Region it is found in the Niagara River, Erie Canal, Hudson River drainage in New York, and possibly Lake Champlain. It is established in the Chesapeake Bay, Maryland. (Ruiz 2000)

In the Great Lakes Region: The first record of this introduced species in the Great Lakes basin is from the Hudson River drainage, connected to the Erie Canal and Mohawk River, in 1867. It was later reported from the Lake Michigan watershed by 1906 and Lake Erie by 1914. Other records are from 1931 near Buffalo, Lake Erie and the Niagara River. The New York State Museum has records from the 1950s and 1960s from 11 counties Mackie et al. (1980) list this species as recorded from Lake Huron, but they do not give the date of establishment, or any references.

References

1. Jokinen, E. 1992. The Freshwater Snails (Mollusca: Gastropoda) of New York State. The University of the State of New York, The State Education Department, The New York State Museum, Albany, New York 12230. 112 pp.
2. Mackie, G. L., D. S. White and T. W. Zdeba. 1980. A guide to freshwater mollusks of the Laurentian Great Lakes with special emphasis on the genus Pisidium. Environmental Research Laboratory, Office of Research and Development, U. S. Environmental Protection Agency, Duluth, Minnesota 55804. 144 pp.
3. Jokinen, E. H. 1984. Periostracal morphology of viviparid snail shells. Transactions of the American Microscopical Society 103(4):312-316.
4. Lee, L. E. J., J. Stassen, A. McDonald, C. Culshaw, A. D. Venosa and K. Lee. 2002. Bioremediation Journal 6(4):373-386.
5. Vincent, B. 1979. Étude du benthos d’eau douce dans le haut-estuaire du Saint-Laurent (Québec). Canadian Journal of Zoology 57(11):1271-2182.
6. Duch, T. M. 1976. Aspects of the feeding habits of Viviparus georgianus. The Nautilus 90(1):7-10.
7. Pace, G. L. and E. J. Szuch. 1985. An exceptional stream population of the banded apple snail Viviparus georgianus in Michigan, USA. Nautilus 99(2-3):48-53.
8. Wade, J. Q. and C. E. Vasey. 1976. A study of the gastropods of Conesus Lake, Livingston County, New York. Proceedings of the Rochester Academy of Science 13(1):17-22.
9. Jokinen, E. H., J. Guerette and R. W. Kortmann. 1982. The natural history of an ovoviviparous snail Viviparus georgianus in a soft water eutrophic lake. Freshwater Invertebrate Biology 1(4):2-17.
10. Wade, J. Q. 1985a. Studies of the gastropods of Conesus Lake, Livingston County, New York, USA II. Identification, occurrence and ecology of species. Proceedings of the Rochester Academy of Science 15(3):206-212.
11. Browne, R. A. 1978. Growth, mortality, fecundity, biomass and productivity of four lake populations of the prosobranch snail, Viviparus georgianus. Ecology 59(4):742-750.
12. Rivest, B. R. and R. Vanderpool. 1986. Variation in capsule albumen in the freshwater snail Viviparus georgianus. American Zoologist 26(4):41A.
13. Vail. V. A. 1978. Seasonal reproductive patterns in 3 viviparid gastropods. Malacologia 17(1):7-98.
14. Vail, V. A. 1977. Observations on brood production in three viviparid gastropods. Bulletin of the American Malacological Union, Inc. 43:90.
15. Buckley, D. E. 1986. Bioenergetics of age-related vs. size-related reproductive tactics in female Viviparus georgianus. Biological Journal of the Linnean Society 27(4):293-310.
16. Wade, J. Q. 1985b. Studies of the gastropods of Conesus Lake, Livingston County, New York, USA III. Endozoic and parasitic organisms obtained from gastropods. Proceedings of the Rochester Academy of Science 15(3):213-215.
17. Burch, J. B. and J. L. Tottenham. 1980. Species list, ranges and illustrations. Pages 82-215. In North American freshwater snails. The University of Michigan, Ann Arbor.
18. Jokinen, E. H. and J. Pondick. 1981. Rare and endangered species: freshwater gastropods of southern New England. The Bulletin of the American Malacological Union, Inc. 50:52-53.
19. Mills, E. L., J. H. Leach, J. T. Carlton and C. L. Secor. 1993. Exotic species in the Great Lakes: a history of biotic crises and anthropogenic introductions. Journal of Great Lakes Research 19(1):1-54.
20. Katoh, M. and D. W. Foltz. 1994. Genetic subdivision and morphological variation in a freshwater snail species complex formerly referred to as Viviparus georgianus (Lea). Biological Journal of the Linnean Society 53(1):73-90.
21. Viviparus georgianus at NatureServe Explorer, accessed 19 October 2008.

This article incorporates public domain text from:

• Rebekah M. Kipp & Amy Benson. 2008. Viviparus georgianus. USGS Nonindigenous Aquatic Species Database, Gainesville, FL. /nas.er.usgs.gov/queries/FactSheet.asp?speciesID=1047> Revision Date: 2/26/2007

External links

• Chemical toxicity studies in Viviparus georgianus