Desmoulin's whorl snail, Vertigo moulinsiana (Dupuy), is protected under Annex IIa of the European Union Habitats and Species Directive. It is a priority species in the UK Biodiversity Action Plan and is listed in the British Red Data Book as an RDB3 (Rare) species.
Desmoulin's whorl snail is considered to be an Atlantic-Mediterranean species with a range extending from Ireland to Russia and south to North Africa. In Europe, the species has been confirmed from Austria, Belgium, Bulgaria, Czech Republic, Denmark, France, Germany, Greece, Hungary, Ireland, Italy, Lithuania, Luxembourg, Netherlands, Poland, Slovakia, Spain, Sweden, Switzerland and the UK. It is also known from Algeria, Azerbijan, Georgia, Morocco, Russia and Turkey. The southern distribution border is poorly known owing to taxonomic confusion with similar species.
The principal causes of decline are wetland drainage (particularly during the 20th century), change in agricultural and management practice, encroachment of scrub onto fen, and change of land use and development. In many countries the status ranges from Vulnerable (for example, in Ireland and Germany) to Endangered (including the Netherlands and Sweden) or Presumed Extinct (Luxembourg). Although recent surveys under the requirements of the Habitats Directive have revealed previously unknown populations, the overall status remains unchanged. With present information, Britain is considered to support the greatest number of Desmoulin's whorl snail populations in the European Union.
In Britain, Desmoulin's whorl snail
occurs principally in a band from east Dorset to north-west Norfolk. Outside
the key area of distribution, V. moulinsiana is known from Cors
Geirch on the Lleyn Peninsula in north Wales, Sweat Mere in Shropshire,
Stodmarsh in Kent, and at Penhale and Perranporth in Cornwall. The greatest
concentrations of individual sites are found in the river catchments of
the Hampshire Basin, the Thames Basin and the Norfolk Broads.
Ecology of Desmoulin's Whorl Snail
Monitoring Desmoulin's Whorl Snail
