Larval trematode infections in Lymnaea glabra populations living in the Brenne Regional Natural Park, central France

Lymnaea glabra is known to be a natural intermediate host of two flukes, Calicophoron daubneyi and Fasciola hepatica, in central France. But it can also sustain larval development of other digeneans. Adult snails were thus collected from 206 habitats in 2014 and 2015 to identify parasite species and determine the prevalence of each digenean infection in relation to the five types of snail habitats. Seven digenean species were noted in 321 infected snails (out of 17,647 L. glabra). Snails with F. hepatica or C. daubneyi were found in 14.5% and 12.6% of habitats, respectively. Percentages were lower for snails with Opisthoglyphe ranae (5.8%), Haplometra cylindracea (5.3%) and were less than 5% for those infected with Echinostoma revolutum, Notocotylus sp. or Plagiorchis sp. Prevalence noted for each parasite species varied with the type of habitat. The number of species in L. glabra was lower than that found in G. truncatula from the same region (7 instead of 10). The distribution and prevalence of each digenean species were thus dependent on the type and location of each snail habitat.