Molluscs

Mollusca (slugs and snails)

Shropshire’s varied geology, ancient woodlands, grasslands and wetlands support at least 70 species of mollusc (snails and slugs).  Some of these are rare and declining nationally and internationally, such as the Annex II species Desmoulin’s Whorl Snail, Vertigo moulinsiana, a specialist of the fens around the meres. However there are very few records for slugs and snails in Shropshire, something that could be redressed quite easily for who has not seen a slug or snail in their garden? The surprising world of European snails is that many species are minute and therefore easily overlooked in a bag of leaf litter, or bucket of mud from a pond.

The mollusc (bivalve) of most conservation concern in Shropshire is the critically endangered Freshwater pearl mussel Margaritifera margaritifera which is declining throughout its range and threatened with extinction. Only a few viable populations survive in about 50 rivers in mainland Europe, including in the River Clun for which the river was classed as a Special Area of Conservation (SAC). Unfortunately it is declining here too, largely due to siltation smothering the river gravels which prevents successful recruitment. The adults can live for more than 100 years but without producing juveniles experts say the population in the Clun may only have 10 years left before extinction at this rate of decline. There is now a captive breeding programme and translocation project for these mussels.

Margmarg resized

Freshwater pearl mussel, Margaritifera margaritifera, River Clun.  Dead specimen, photo taken under licence with Natural England, M. Cousins, 2014

Please send your mollusc records to Mags Cousins  shropshiremolluscs@gmail.com

Shropshire mollusc records will be forwarded Adrian Norris the National Non-marine Recorder at the Conchological Society of Great Britain and Ireland http://www.conchsoc.org/ for inclusion in the national recording scheme.

Reports

In the SEDN Reports Dropbox folder you can find reports on:

  • Molluscs of the Meres
  • Omphiscola glabra at Brown Moss
  • Omphiscola glabra in Shropshire

Identification guides and sources of information

Recent publications have made mollusc identification much more accessible:

aidgapNaggs, F. et al, 2014 An illustrated guide to the land snails of the British Isles, NHM London, The Conchological Society of GB and Ireland and The Malacological Society of London. This A5 fold out laminated identification chart includes colour pictures of all known British and Irish snail species and 11 hothouse aliens.

Cameron, R., 2008 Land Snails in the British Isles, AIDGAP and FSC publications, Second Edition.

Rowson, B., 2014 Slugs of Britain and Ireland, AIDGAP and FSC publications.

 

Odonata >>

Clausilia bidentata

Two-toothed Door Snail, Clausilia bidentata, on a wall at Benthall Edge (M. Cousins)

Vmoulinsiana_New1

Desmoulin’s Whorl Snail, Vertigo moulinsiana, from Fenemere SSSI, less than 2.5 mm in height and showing the apertural teeth, an important character in this genus. Photo R. Burkmar

Cep nem resized

Brown-lipped Snail Cepaea nemoralis, at Gardiner’s Bank. Photo: M. Cousins

 

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