Omphiscola glabra
Encyclopedia
Omphiscola glabra is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of small to medium-size, air-breathing, freshwater snail
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....

, an aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 pulmonate gastropod mollusk in the family Lymnaeidae
Lymnaeidae
Lymnaeidae is a taxonomic family of small to large air-breathing freshwater snails, aquatic pulmonate gastropod mollusks, that belong to the clade Hygrophila....

.

Distribution

This European snail can be found from southern Scandinavia
Scandinavia
Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...

 (61° N) to southern Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

.
  • endangered in Germany. Critically endangered in Western Germany (Rheinland-Pfalz, Saarland, Nordrhein-Westfalen, Hessen). Extinct in Bavaria.
  • Netherlands
  • one site in the south east of Ireland was found in 2009, but it is listed as extinct at at local red list (2009).
  • vulnerable in Great Britain


The distribution of Omphiscola glabra is very scattered and rare. It is seriously threatened, at many places extinct. It is threatened by continuous habitat destruction
Habitat destruction
Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of...

 by drainage
Drainage
Drainage is the natural or artificial removal of surface and sub-surface water from an area. Many agricultural soils need drainage to improve production or to manage water supplies.-Early history:...

 and intensive farming
Intensive farming
Intensive farming or intensive agriculture is an agricultural production system characterized by the high inputs of capital, labour, or heavy usage of technologies such as pesticides and chemical fertilizers relative to land area....

. Acriculturally induced eutrophication
Eutrophication
Eutrophication or more precisely hypertrophication, is the movement of a body of water′s trophic status in the direction of increasing plant biomass, by the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system...

 and dreinage are threats. Omphiscola glabra has disappeared widely from urbanized areas such as London.

Shell description

The shell
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

 is strongly cylindrical, horny, often with colored with brownish or blackish cover, apex
Apex (mollusc)
Apex is an anatomical term for the tip of the mollusc shell of a gastropod, scaphopod, or cephalopod mollusc.-Gastropods:The word "apex" is most often used to mean the tip of the spire of the shell of a gastropod...

 blunt, 7-8 moderately convex whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

, with last whorl being twice as high as the narrow aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

, and with aperture often with white lip.

The height of the shell is 9–12 mm, up to 15 mm or up to 20 mm. The width of the shell is 3–4 mm, up to 5.5 mm.

Habitat

This snail lives in places such as swampy meadows and ditches.

Omphiscola glabra occur in small waters rich in vegetation, swamps and standing forest waters with leaf litter, often in water with organic iron contents and low calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

 contents. In Britain, they occur in small standing waters low in nutrients, with poor aquatic flora, often in waters drying out periodically. They usually do not occur in habitats with high molluscan diversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...

, and usually on uncultivated land. They are calciphile and have a pH tolerance of 5.4-8.8.

Reproduction begins in May. Juveniles hatch after 15–25 days. Omphiscola glabra has two generations per year.

Parasites

Omphiscola glabra can serve as intermediate host of several digenea
Digenea
Digenea is a subclass within the Platyhelminthes consisting of parasitic flatworms with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults are particularly common in the digestive tract, but occur throughout the organ systems of all classes of vertebrates...

n trematodes. In France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, Omphiscola glabra was naturally infected with Fasciola hepatica
Fasciola hepatica
Fasciola hepatica, also known as the common liver fluke or sheep liver fluke, is a parasitic flatworm of the class Trematoda, phylum Platyhelminthes that infects the livers of various mammals, including humans. The disease caused by the fluke is called fascioliasis . F...

, Paramphistomum daubnei, and Haplometra cylindracea. Moreover, recent report suggested that the species is also susceptible to Fascioloides magna
Fascioloides magna
Fascioloides magna, also known as giant liver fluke, large American liver fluke or deer fluke, is an important parasite of a variety of wild and domestic ruminants in North America and Europe. Adult flukes occur in the liver of the definitive host and feed on blood...

infection.
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