BC Conservation Data Centre: Conservation Status Report
Vallonia cyclophorella
Silky Vallonia
| Scientific Name: | Vallonia cyclophorella |
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| English Name: | Silky Vallonia |
| Provincial Status Summary | |
| Status: | S4S5 |
| Date Status Assigned: | December 01, 2015 |
| Date Last Reviewed: | March 10, 2025 |
| Reasons: | This species is widespread across central and southern BC, with a group of records in the Peace River area. Although there are few records overall, this small snail is found in relatively common habitats, such as leaf litter, grass, and beneath dead wood on bunchgrass slopes, as well as in open, dry, and rocky areas. It is likely more common than the number of known occurrences suggests. |
| Range | |
| Range Extent: | G = 200,000-2,500,000 square km |
| Range Extent Comments: | The range extent of this species is at least 184, 600 km2. It is known from southern BC on bunchgrass slopes, in open, dry forests, and in rocky areas (Forsyth 2004), as well as in five locations in the Peace River Valley, between Hudson's Hope and Bear Flats, west of Fort St. John (Forsyth 1999; Forsyth 2004, 2014; Royal BC Museum Invertebrate Collection, accessed 21 November 2024; GBIF, accessed 20 November 2024). |
| Area of Occupancy (km2): | U = Unknown |
| Occurrences & Population | |
| Number of Occurrences: | CE = 21 to >300 |
| Comments: | There are at least 15 known occurrences scattered over a large area in BC. They are known from several places in the Hudson Hope/Peace River region, there is a specimen from Lillooet, Skaha Lake, NE of Lytton, Skookumchuck (Kootenay River), south of Kamloops and the Ashnola River (Royal BC Museum Invertebrate Zoolgy Collection, accessed 21 November 2024; Gerber 1996, cited by Forsyth 1999; Forsyth 2003a, 2004). The broad range of potential records reflects the large range extent and common habitat. There are no iNaturalist records (iNaturalist, accessed 21 November 2024). |
| Number of Occurrences with Good Viability / Ecological Integrity: | U = Unknown |
| Number of Occurrences Appropriately Protected & Managed: | Rank Factor not assessed |
| Population Size: | U = Unknown |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | U = Unknown |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | U = Unknown |
| Long-Term Trend: | U = Unknown |
| Other Factors | |
| Intrinsic Vulnerability: | Rank Factor not assessed |
| Comments: | Valloniids are largely self-fertilizing and possibly clonal (Forsyth 2005). |
| Environmental Specificity: | D=Broad. Generalist or community with all key requirements common. |
| Comments: | Found in leaf litter, grass and under dead wood on bunchgrass slopes; in open, dry forests and in rocky areas (Forsyth 2004). |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | |
| Inventory Needs: | |
| Stewardship | |
| Protection: | |
| Management: | |
| Version | |
| Author: | Ramsay, L. (2024), Forsyth, R. and L. Gelling (2015) |
| Date: | November 20, 2024 |
| References | |
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Forsyth, R.G. 1999. Terrestrial gastropods of the Columbia Basin, British Columbia.Living Landscapes, Royal British Columbia Museum, Victoria. Available: http://www.livinglandscapes.bc.ca/cbasin/molluscs/contents.html. Accessed February 12, 2004.
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Forsyth, R.G. 2003a. Land snails of British Columbia. Online. Available: http://www3.telus.net/rforsyth/index.html (no longer available)
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Forsyth, R.G. 2004. Land snails of British Columbia. University of British Columbia Press. Vancouver, BC. 176pp.
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Forsyth, R.G. 2005. Comments on provisional ranks of British Columbia terrestrial molluscs. Unpubl. rep. submitted to the B.C. Minist. Sustainable Resour. Manage., Conservation Data Centre, Victoria, BC. 18pp.
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GBIF.org. 2024af. GBIF. Occurrence download for Vallonia cyclophorella. Accessed 20 November 2024.
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Gerber, J. 1996. Revision der Gattung Vallonia Risso 1826 (Mollusca: Gastropoda: Valloniidae). Schriften zur Malakozoologie aus dem Haus der Natur-Cismar 8:1-227 (Article not seen, citation from Forsyth, R.G. 2004. Land snails of British Columbia. University of British Columbia Press. Vancouver. 176pp.)
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iNaturalist community. 2024. Observations of Vallonia cyclophorella from British Columbia, Canada. Exported from www.inaturalist.org on 21 November 2024.
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Royal British Columbia Museum. 2015. Electronic database of terrestrial and aquatic mollusc records of the Royal BC Museum.
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Royal British Columbia Museum. 2016. Electronic database containing invertebrates specimens collected during the 2015 Biological Survey of Canada Bio-Blitz: Peace Region, British Columbia June 22-26.
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Please visit the website Conservation Status Ranks for information on how the CDC determines conservation status ranks. For global conservation status reports and ranks, please visit the NatureServe website http://www.natureserve.org/.
Suggested Citation:
B.C. Conservation Data Centre. 2024. Conservation Status Report: Vallonia cyclophorella. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 13, 2026).