A qPCR assay for the rapid and specific detection of Shining ram’s-horn
snail (Segmentina nitida) eDNA from Stodmarsh National Nature Reserve,
UK
Abstract
Segmentina nitida Müller 1774 is a freshwater snail which was formerly
widespread throughout England and south Wales. Since the 1840s it has
seen a rapid decline in its range which has been attributed to
deteriorating water quality due to nutrient enrichment, lowering of
water tables and over-management of the ditches in which it resides.
Segmentina nitida has therefore been identified as a UK Biodiversity
Action Plan (UKBAP) priority species which recommends further research
for its conservation. Here we have developed a Taqman based qPCR eDNA
assay for the detection of S. nitida at the Stodmarsh National Nature
Reserve and compared the results with a manual survey of the ditches at
this location. Our eDNA analysis exhibited an observed percentage
agreement of 84% with a kappa coefficient of agreement between manual
and eDNA surveys of 0.56. Three ditches determined to be negative for
Segmentina nitida by eDNA analysis were manual survey positive, and a
further two ditches that were negative by manual survey were positive by
eDNA analysis revealing the potential for improved overall detection
rates using a combination of manual and eDNA methodologies. eDNA
analysis could therefore augment manual survey techniques for Segmentina
nitida as a relatively quick and inexpensive tool for collecting
presence and distribution data that could be used to inform manual
surveys and management of ditches.