Arianta arbustorum
Encyclopedia
Arianta arbustorum is a medium-sized 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 land snail
Land snail
A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...

, sometimes known as the "copse snail", a terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

 pulmonate gastropod mollusk in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Helicidae
Helicidae
The Helicidae, sometimes known as the typical snails, are a taxonomic family of small to large, air-breathing, land snails. In other words, they are terrestrial pulmonate gastropod mollusks....

.

Subspecies

Several subspecies are recognized by some authors:
  • Arianta arbustorum alpicola Férussac, 1821
  • Arianta arbustorum arbustorum
  • Arianta arbustorum canigonensis
  • Arianta arbustorum picea
  • Arianta arbustorum pseudorudis
  • Arianta arbustorum repellini
  • Arianta arbustorum styriaca
  • Arianta arbustorum vareliensis

Distribution

This species is native to Europe:
  • North-western and central Europe with Alps and Carpathians
  • Netherlands
  • Austria
  • Czech Republic
  • Slovakia
  • Poland
  • Switzerland. One of the most frequent species of land snails in Switzerland, can be very abundant, up to 20 adults per square meter.
  • eastern Pyrenees, Spain
  • Norway
  • Iceland
  • the British Isles: Great Britain and Ireland In Britain the species suffered slightly from intensive farming and the continuous destructions of suitable uncultivated refuges. It is rare in Ireland.
  • Kaliningrad
  • Finland. In Finland, it has become so common in the Porvoo
    Porvoo
    Porvoo is a city and a municipality situated on the southern coast of Finland approximately east of Helsinki. Porvoo is one of the six medieval towns in Finland, first mentioned as a city in texts from 14th century...

     region east of Helsinki, that it is locally called the "Porvoo snail".
  • Estonia
  • Latvia
  • scattered to Serbia
  • BulgariaIts is rare in Bulgaria.
  • western Ukraine


This species has not yet become established in the USA, but it is considered to represent a potentially serious threat as a pest, an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....

 which could negatively effect agriculture, natural ecosystems, human health or commerce. Therefore it has been suggested that this species be given top national quarantine
Quarantine
Quarantine is compulsory isolation, typically to contain the spread of something considered dangerous, often but not always disease. The word comes from the Italian quarantena, meaning forty-day period....

 significance in the USA.

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 usually brown with numerous pale yellowish rows of spots and usually with a brown band above the periphery, occasionally yellowish, reddish or with greenish hue, weakly striated and with fine spiral lines on the upper side. The shell has 5-5.5 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 deep suture. The last whorl is slightly descending near the 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....

. The aperture is with prominent white lip inside. The apertural margin is reflected. Umbilicus is entirely covered by the reflected columellar margin.

The width of the shell is 18-25 mm. The height of the shell is 12-22 mm. Dimensions are locally variable.

The shell shape is globular in most present-day populations, but originally is believed to have been depressed in the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

, before lowlands were invaded and shells became globular, re-invading mountain regions except some isolated spots among glaciers.

The animal is usually black.

Life cycle

Arianta arbustorum lives in forests and open habitats of any kind. It requires humidity. It lives also in disturbed habitats (not in Ireland where it is restricted to old native woodland). It may locally tolerate non-calcareous substrate, in north Scotland also on sandhills. In the Alps up to 2700 m, in Britain 1200 m, in Bulgaria 1500 m.

It feeds on green herbs, dead animals and faeces.

If snails hatched more than 50 m distant from each other, they are considered isolated since they would not move more than 25 m (neighbourhood area 32-50 m), usually they move about 7-12 m in a year, mostly along water currents.

This species of snail makes and uses calcareous love darts during mating. Reproduction is usually after copulation, but self-fertilization is also possible. The size of the egg is 3.2 mm. Maturity is reached after 2-4 years. The maximum age up to 14 years.

Angiostrongylus vasorum
Angiostrongylus vasorum
Angiostrongylus vasorum, also known as French heartworm, is a species of parasitic nematode in the family Metastrongylidae. It causes the disease canine angiostrongylosis in dogs.Not much is known about the biology of this species.- Description :...

has successfully experimentally infected this snail.
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