3 Molluscs

3 Molluscs
Vertigo angustior
Narrow-mouthed Whorl Snail
Vertigo angustior
Jeffreys, 1830
Narrow-mouthed Whorl Snail
Latin synonyms: Turbo vertigo Montagu, 1803; Vertigo
venetzii Charpentier, 1822;
Vertigo plicata A. Müller, 1838
Taxonomic classification:
Order: Terrestrial pulmonates, Stylommatophora
Family: Vertigos, Vertiginidae
Status: EN – Endangered
Narrow-mouthed whorl snail (Vertigo angustior)
M. Horsák
Morphology Narrow-mouthed whorl snail is a tiny
gastropod, the shell height not exceeding 1,8mm,
the width 0,9mm. The shell is sinistral, with 5 rather
strongly convex whorls, the last flattened laterally and
narrowed basally giving a somewhat fusiform outline.
Mouth-edge delicately thickened, sharply reflected;
outer lip a deep central indentation, continued externally
as a spiral groove and internally corresponding
with a long lamella-like upper palathal tooth; mouth
with 5–6 teeth. Shell pale redish or yellowish-brown,
rather glossy, with numerous close and regular fine
growth-ridges, especially on the erlier whorls.
Bionomiy A calciphile species. It inhabits especially
non-forested areas, basophilic, wet, even waterlogged
valley meadows, wetland habitats and
meadow springs with tufa formation, fens. It lives in
grass, decaying vegetation in the layer of plant litter,
or in moist moss. It creeps also on plant stalks up to
the height of 10–15cm. Localities on water banks
are also known. Sporadically it occurs also in rock
debris with higher and stable moisture (Krupinské
bralce rocks in the Štiavnické vrchy Mts.). In general,
the narrow-mouthed whorl snail is considered an
univoltine species. It feeds probably on detritus and
decaying organic plant material, possibly on microorganisms
present in the decaying process (micromycetes,
algae, etc.)
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