Arianta arbustorum

Arianta arbustorum alpicola

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

This species is native to Europe:

• North-western and central Europe with Alps and Carpathians[3]
• Netherlands[4]
• 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.[3]
• eastern Pyrenees, Spain[3]
• Norway[3]
• Iceland[3]
• Faroe Islands[5]
• the British Isles: Great Britain and Ireland[3] In Britain the species suffered slightly from intensive farming and the continuous destructions of suitable uncultivated refuges.[3] It is rare in Ireland.[3]
• Kaliningrad[3]
• Finland. In Finland, it has become so common in the Porvoo region east of Helsinki, that it is locally called the "Porvoo snail".
• Estonia[3]
• Latvia[3]
• scattered to Serbia[3]
• Bulgaria[3] It is rare in Bulgaria.[3]
• western Ukraine[3]

Arianta arbustorum is introduced to North America, but is only known from Canada, where established populations are known from Newfoundland, New Brunswick, Ontario,[6] and Prince Edward Island.[7]

This species has not yet become established in the US, but it is considered to represent a potentially serious threat as a pest, an invasive species which could negatively affect agriculture, natural ecosystems, human health or commerce. Therefore, it has been suggested that this species be given top national quarantine significance in the USA.[8]

apertural view of the shell of Arianta arbustorum (top left); lateral view (top right); apical view (bottom left) and umbilical view (bottom right)

The shell 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.[3] The shell has 5-5.5 convex whorls with deep suture.[3] The last whorl is slightly descending near the aperture.[3] The aperture is with prominent white lip inside.[3] The apertural margin is reflected.[3] Umbilicus is entirely covered by the reflected columellar margin.[3]

The width of the shell is 18–25 mm.[3] The height of the shell is 12–22 mm.[3] Dimensions are locally variable.[3]

The shell shape is globular in most present-day populations, but originally is believed to have been depressed in the Pleistocene, before lowlands were invaded and shells became globular, re-invading mountain regions except some isolated spots among glaciers.[3]

The animal is usually black.[3]

Arianta arbustorum lives in forests and open habitats of any kind.[3] It requires humidity.[3] It lives also in disturbed habitats (not in Ireland where it is restricted to old native woodland).[3] It may locally tolerate non-calcareous substrate, in north Scotland also on sandhills.[3] In the Alps up to 2700 m, in Britain 1200 m, in Bulgaria 1500 m.[3]

It feeds on green herbs, dead animals and faeces.[3]

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.[3]

drawing of love dart of Arianta arbustorum

This species of snail makes and uses calcareous love darts during mating. Reproduction is usually after copulation, but self-fertilization is also possible.[3] The size of the egg is 3.2 mm.[9] Maturity is reached after 2–4 years.[3] The maximum age up to 14 years.[3]

Angiostrongylus vasorum has successfully experimentally infected this snail.[10]

This article incorporates public domain text from the reference.[3]

Wikimedia Commons has media related to Arianta arbustorum.

• Arianta arbustorum at Animalbase taxonomy,short description, distribution, biology,status (threats), images
• Arianta arbustorum images at Encyclopedia of Life