''Chilostoma adelozona'' is a species of medium-sized, air-breathing,

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...

, a

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

pulmonate Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group inclu ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the family

Helicidae Helicidae is a large, diverse family of western Palaearctic, medium to large-sized, air-breathing land snails, sometimes called the "typical snails." It includes some of the largest European land snails, several species are common in anthropoge ...

, the true snails. The species is endemic to Switzerland, and is currently classified as Vulnerable by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

Taxonomy

Although first mentioned by

Pellegrino Strobel Pellegrino Strobel (22 August 18218 June 1895) was an Italian ornithologist, zoologist, naturalist and Italian politician. He is considered among the leaders of Italian malacology and, with Gaetano Chierici and Luigi Pigorini, is an important fig ...

in 1857 as a variety of ''Helix foetens'', that name was never validly described and is treated as a ''

nomen nudum In Taxonomy (biology), taxonomy, a ''nomen nudum'' ('naked name'; plural ''nomina nuda'') is a designation which looks exactly like a scientific name of an organism, and may have originally been intended to be one, but it has not been published ...

''. In 1864 Guiseppe Stabile provided the first

formal description A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

, publishing it under the varietal name ''Helix foetens'' var. ''cisalpina'', which later authors elevated to species rank as ''Chilostoma adelozona'' (Stabile, 1864). Modern checklists, such as ''

Fauna Europaea Fauna Europaea is a database of the scientific names and distribution of all living multicellular European land and fresh-water animals. It serves as a standard taxonomic source for animal taxonomy within the Pan-European Species directories Infr ...

'', recognise two

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

: the nominotypical ''C. adelozona adelozona'' and ''C. adelozona rhaeticum''.

Description and variation

The shell is broadly tumid—bulging in profile—and measures 16–29 mm across with a height of about 14 mm. It has 4–5 slightly convex

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). In nature File:Photograph and axial plane floral diagra ...

s (the spiral turns of the shell) separated by a clear suture, and a wide, off-centre

umbilicus Umbilicus may refer to: *The navel or belly button *Umbilicus (mollusc), a feature of gastropod, Nautilus and Ammonite shell anatomy *Umbilicus (plant), ''Umbilicus'' (plant), a genus of over ninety species of perennial flowering plants *Umbilicus ...

(the hollow at the shell's base). The overall hue is pale horn-coloured, usually with a faint brown band around the periphery and a paler zone immediately beneath. The

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

(shell opening) is set obliquely and is edged by a white, reflected lip. Populations of the nominotypical subspecies occur mainly on

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime (mineral), lime or being chalky. The term is used in a wide variety of Science, scientific disciplines. In zoology ''Calcare ...

cliffs between

Lake Lugano Lake Lugano ( or , from ; ) is a glacial lake which is situated on the border between southern Switzerland and northern Italy. The lake, named after the city of Lugano, is situated between Lake Como and Lago Maggiore. It was cited for the first t ...

and

Brescia Brescia (, ; ; or ; ) is a city and (municipality) in the region of Lombardy, in Italy. It is situated at the foot of the Alps, a few kilometers from the lakes Lake Garda, Garda and Lake Iseo, Iseo. With a population of 199,949, it is the se ...

, whereas ''C. adelozona rhaeticum'' inhabits talus slopes under heavy boulders—often non-calcareous—in eastern Alpine localities such as

Valtellina Valtellina or the Valtelline (occasionally spelled as two words in English: Val Telline; (); or ; ; ) is a valley in the Lombardy region of northern Italy, bordering Switzerland. Today it is known for its ski centre, hot spring spas, bresa ...

, around 1,500 metres elevation. Shell form and banding can vary considerably with geography and

microhabitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

Distribution and habitat

''Chilostoma adelozona'' is native to the southern Alps of northern Italy (particularly

Lombardy The Lombardy Region (; ) is an administrative regions of Italy, region of Italy that covers ; it is located in northern Italy and has a population of about 10 million people, constituting more than one-sixth of Italy's population. Lombardy is ...

and

Alto Adige South Tyrol ( , ; ; ), officially the Autonomous Province of Bolzano – South Tyrol, is an autonomous province in northern Italy. Together with Trentino, South Tyrol forms the autonomous region of Trentino-Alto Adige/Südtirol. The provinc ...

) and adjacent areas of Switzerland. It favours

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

rock habitats—vertical or overhanging faces, rocky

outcrop An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth and other terrestrial planets. Features Outcrops do not cover the majority of the Earth's land surface because in most p ...

s and scree—at elevations from about 1,500 m up to 1,800 m. Moisture for this snail is supplied by

seepage In soil mechanics, seepage is the movement of water through soil. If fluid pressures in a soil deposit are uniformly increasing with depth according to u = \rho_w g z_w, where z_w is the depth below the water table, then hydrostatic conditions wi ...

from snowmelt and persistent damp crevices, making these cool, shaded rock environments essential for its survival.

References

{{Taxonbar, from=Q14625308 Chilostoma Gastropods described in 1857