Pomatias elegans

Pomatias elegans
A live and active individual of Pomatias elegans; note how the back of the shell rests on the operculum on the upper surface of the tail
Live but retracted individual showing shell and operculum with its eccentric nucleus
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
(unranked): clade Caenogastropoda
clade Littorinimorpha
Superfamily: Littorinoidea
Family: Pomatiidae
Subfamily: Pomatiinae
Genus: Pomatias
Species: P. elegans
Binomial name
Pomatias elegans
(O. F. Müller, 1774)
Synonyms

Cyclostoma elegans

Distribution in Europe
Pomatias elegans in motion

Pomatias elegans, common name the round-mouthed snail, is a species of small land snail with an operculum, a terrestrial gastropod mollusk in the family Pomatiidae within the superfamily Littorinoidea, the winkles and their allies.

This species is sometimes called a "land winkle".[1]

Distribution

This species is very common in Southern Europe. Its overall distribution extends as far east as Istanbul and across the Bosphorus from there. It is uncommon in Britain and central Europe. Its distribution in North Africa is poorly documented.[2]

Habitat

This snail lives only in areas where there are high levels of calcium carbonate such as on limestone or chalk rock, and where there is loose and friable soil. This snail is also sometimes found in coastal sand dunes where the sand has many shell fragments mixed in.

Description

The shell of this species is thick-walled, ovoid and slightly conical. It is composed of 4 ½ - 5 convex spires with the last one as the largest one. The surface of the shell is reticulated with dark spots and discontinued bands of beige and violet colours. The thick and chalky operculum has an eccentric calcified nucleus, and bears a spiral sculpture. The length of the shells varies between 12.5 mm and 15.8 mm and its diameter between 7 mm and 11.5 mm.[3]

The waves of contractions on the surface of the foot are longitudinal, passing from side to side.

Threatened

The survival of this species is threatened in Central Europe by intensive farming, also in vineyards by habitat destruction, fertilizers, insecticides, herbicides and fungicides. The species has seriously declined in central and eastern England. This species is endangered in Switzerland and Ireland, and vulnerable in Germany.

A live but inactive individual of Pomatias elegans

References

  1. Journal of Molluscan Studies, GENETIC AND MORPHOLOGICAL VARIATION IN THE LAND WINKLE POMATIAS ELEGANS (MÜLLER) (CAENOGASTROPODA: POMATIASIDAE) Volume 67, Issue 2, pp 145–152 (http://mollus.oxfordjournals.org/content/67/2/145.abstract) Accessed 2014-9-2
  2. Fauna Europaea
  3. Monia Ben Romdhane; Chahrazed El Hefdi; Mohamed Ben Dalem (2008). "Première mention de Pomatias elegans (O.F. MÛller, 1774) au Nord de la Tunisie" (PDF). MalaCo, 5 : 254-255. www.journal-malaco.fr. Retrieved 2008-10-14.
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