Each coin has 2 sides: a positive role of alien<i>Potamopyrgus antipodarum</i>(Grey, 1843) snails in reducing the infection of native lymnaeids with trematodes

Abstract The change in the distribution of organisms freshwater ecosystems due to natural or manmade processes raises question impact alien species on local communities. Although most studies indicate a negative effect, positive one is more difficult discern, especially multispecies systems, including hosts and parasites. purpose study was check whether presence an host, Potamopyrgus antipodarum, reduces intensity Echinoparyphium aconiatum metacercariae native Radix spp. We additionally tested water temperature biomass host dilution effect. experimentally studied (1) lifespan echinostome cercariae different temperatures, (2) infectivity toward (3) host. found that cercarial survival were dependent. However, decreased with increasing temperature, contrary infectivity. Echinostome entered renal cavity both successfully transformed into metacercariae. number Our results lymnaeids may benefit from co-occurrence P. as additional origins reduce prevalence parasites scale effect depends not only increased spectrum susceptible but also other variables environment, density.