Galba Truncatula

''Galba truncatula'' (previously: ''Lymnaea truncatula'') is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.Neubauer, Thomas A. (2014). Galba (Galba) truncatula (Müller, 1774). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=822446 on 2014-11-17

''Galba truncatula'' is the vector mainly involved in fascioliasis transmission to humans.

Distribution

''Galba truncatula'' is believed to be native to Europe, but it has been introduced in other parts of the world. Currently, ''Galba truncatula'' is commonly distributed in all European countries, including most Mediterranean islands such as Corsica, Malta, the Azores, Madeira, the Faroe Islands, the Balearic Islands, and the Canary Islands. Despite the fact that ''Galba truncatula'' has spread worldwide, exact distribution maps of the species are not available. In addition, most reports are based on morphological determination of the snail. Molecular evidences on the presence of ''Galba truncatula'' from non-European areas are limited. ''Galba truncatula'' has also been found in North and South America, several parts of Africa, and Asia.

In South America, the presence of ''Galba truncatula'' has already been molecularly verified in Bolivia, Peru, Argentina, Chile and Venezuela. In Africa, ''Galba truncatula'' is present mainly in Northern parts (i.e. Morocco, Algeria, Tunis, Egypt) but also in South Africa, Ethiopia, Kenya, and Tanzania.

In Asia, the snail occurs in Russia but other Asian countries were reported very rarely. ''Galba truncatula'' was found in Iran, Pakistan and in Kashmir.

Description

The height of the shell is 5–10 mm and the width of the shell is 2.5–6 mm.

The maximum length of the shell is 12.00 mm. Whorls are stepped. The columella is folded.

Tentacles are wider and with a wide base. Eyes are small. Mantle roof shows larger unpigmented whitish spots giving a pale appearance to the shell of living specimens by transparency.

The first bilateral teeth is tricuspid in radula. The praeputium/penis sheath length ratio is 2.50–5.90 mm (mean 3.44 mm).

Two species that have a similar morphology: ''Galba neotropica'' and ''Galba schirazensis''. Although several phenotypic characteristics may a priori be helpful for a preliminary specimen classification, a definitive classification of a specimen can only be obtained by the sequencing of at least one of the molecular markers used: ITS-2, ITS-1, 16S and cox1. Moreover, mixed populations of ''Galba truncatula'' and ''Galba schirazensis'' have already been described in the field.

Ecology

Habitat

''Galba truncatula'' can occupy both temporary and permanent freshwater ecosystems. The species occurs commonly in shallow well aerated water, in marshes, ponds, lakes, streams, rivers, water ditches.Glöer P. (2002). Überfamilie Lymnaeoidea Rafinesque 1815. Familie Lymnaeidae Lamarck 1812. In: Glöer P. (ed.) ''Die Süßwassergastropoden Nord-und Mitteleuropas''. Bestimmungschlüssel, Lebensweise, Verbreitung. Die Tierwelt Deutschlands 73. Conchbooks, Hackenheim, pp. 200–232. In France, the populations of ''Galba truncatula'' are declining because its habitat is threatened by modern agricultural practices. In case of larger water bodies, the snail occurs mostly on the edge between water and land, sometimes outside water layer on mud. ''Galba truncatula'' can be very abundant, with high population densities and it has an evident anthropophily including usual presence in human neighbourhood.

''Galba truncatula'' is amphibious organism and can survive long dry periods. This is caused by its high ability to aestivate during drought conditions. It is known that ''Galba truncatula'' can survive 6 weeks to 4.5 months of dry periods in aestivated stage in mud. In the laboratory cultures, Kendall (1949) observed survival over 1 year in Petri dishes without water.

The species requires alkaline pH (pH range 7.0 up to 9.6) Nilsson C., Ericsson U., Medin M., Sundberg I. (1998). ''Sötvattenssnäckor i södra Sverige – en jämförelse med 1940-talet''. Naturvårdsverket Rapport 4903. and calcium content over 0.3 mekv/L.

''Galba truncatula'' can live at a very high altitude such as in the Northern Bolivian Altiplano (an area located between 3800 and 4100 m high altitude).

Feeding habits

''Galba truncatula'' feed on algae and fresh or decomposed parts of plants. Beran L. (1998) ''Vodní měkkýši ČR''. Metodika ČSOP 17, ČSOP Vlašim, 113 pp.

Life cycle

In Europe, it has usually 2 generations per year and snails can live up to 2 years. Jackiewicz M. (2000). ''Blotniarky Europy (Gastropoda: Pulmonata: Lymnaeidae)''. Wydawnictwo Kontekst, Poznań. 115 pp. During very wet years, the species can produce occasionally 3 generations per year.

They are hatching from eggs. The shape of egg cluster is rounded to oval shape even when containing more eggs. There are usually 2–15 eggs in cluster.

Parasites

''Galba truncatula'' is an intermediate host for these known trematodes and nematodes:
* ''Fasciola hepatica''
* ''Fasciola gigantica''
* ''Fascioloides magna''
* '' Haplometra cylindracea''
* '' Plagiorchis'' spp.
* '' Opisthioglyphe'' spp.
* '' Calicophoron daubneyi''
* '' Muellerius capillaris''

Transmission capacity of fascioliasis to humans and to animals is high.

References

This article incorporates CC-BY-2.0 text from the reference

Further reading

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D. Rondelaud and C. Vareille-Morel, ''The chemical and biological control of Lymnaea truncatula in natural watercress beds in the Limousin region (France)''; Parasite Volume 1, Number 1, March 1994
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External links

''Galba truncatula''
at Animalbase taxonomy, short description, distribution, biology, status (threats), images

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Lymnaeidae
Gastropods of Asia
Gastropods of Europe
Molluscs of South America
Gastropods described in 1774
Taxa named by Otto Friedrich Müller