Cepaea spp. as a source of Brachylaima mesostoma (Digenea: Brachylaimidae) and Brachylecithum sp. (Digenea: Dicrocoeliidae) larvae in Poland

Abstract

Parasite diagnostics were carried out on 11 Polish populations of Cepaea spp. In three of them, coming from the roadside ditches of a village (Rytel, northern Poland), very high (up to 60%) prevalence of Brachylaima mesostoma was observed. This study provides the first molecular evidence of the presence of B. mesostoma inside Cepaea spp. in Europe. In a few snails from a population found in a private garden in a small town (Chełmża, northern Poland), larvae of Brachylecithum sp. were present. Cercariae and/or metacercariae of B. mesostoma were observed in both species of Cepaea: C. hortensis and C. nemoralis, whereas larvae of Brachylecithum sp. were found only in C. nemoralis. Both species of parasites inhabited snail hepatopancreas whose structure was significantly damaged by larvae. There was no significant connection between parasite invasion and snail host morphotype. The research did not allow the reasons for the high prevalence of B. mesostoma in Cepaea spp. to be explained, and also did not explicitly indicate how the parasite invaded Cepaea spp. individuals making them, at the same time a second intermediate host. However, it poses important questions about the life cycle of the parasite that may threaten extensively kept small-size farms of poultry.

Morph-dependent nematode infection and its association with host movement in the land snail Cepaea nemoralis (Mollusca, Gastropoda)

“…3 ). These results are consistent with another study analyzing both C. nemoralis and C. hortensis (Żbikowska et al ., 2020). We must acknowledge however that snail infection by trematodes is highly seasonal: infections by Brachylaima seem to be at their highest in fall (Gracenea & Gállego, 2017), while we sampled during spring.…”

“…Gérard et al ., 2020), which would likely have a stronger effect on snail behaviour. Indeed, sporocysts can cause high damage, direct and indirect, to that key organ for digestion and for energy storage (Segade et al ., 2011; Żbikowska et al ., 2020).…”

Brachylaima spp. (Trematoda) parasitizing Cornu aspersum (Gastropoda) in France with potential risk of human consumption

“…Two other land snail species, the helicids Cepaea nemoralis and Cepaea hortensis, were previously found to harbor Brachylaima metacercariae at another site in France (i.e., Richelieu located at 110 km from Arçais and 190 km from Thorigné-Fouillard as the crow flies), but without description of the parasite species [11]. In Poland, a recent study described the occurrence of Brachylaima mesostoma cercariae and metacercariae in three among 11 populations of C. nemoralis and C. hortensis, with spring prevalence up to 54% and 60%, respectively [60]. In our study, C. aspersum was found to act as both first and second intermediate host in Arçais, whereas only as second in Thorigné-Fouillard.…”

“…The life cycle of B. mesostoma was previously described in the Ukraine; there, it does not involve C. aspersum but the hygromiid Xeropicta krynickii as a first intermediate host and various terrestrial snails (Xeropicta krynickii, Helicopsis retowskii, Helicopsis filimargo, Eobania vermiculata, Brephulopsis cylindrica, Brephulopsis bidens, Thoanteus gibber) as second hosts [57]. Recently, B. mesostoma was identified in C. nemoralis and C. hortensis from Poland used both as first and second intermediate hosts [60]. Concerning the second Brachylaima species, which is undetermined, both molecular results and similarities in metacercariae morphometrics imply that it may occur at both sites, using C. aspersum as first and second intermediate host.…”

“…It is worth highlighting the increasing worldwide interest in Brachylaima spp. infecting other terrestrial snail species, according to recent studies (e.g., [59,60]). In France, a country bordering Spain, people consume between 25,000 and 30,000 tons of edible land snails per year, among them 800-1000 tons of C. aspersum produced on farms [32].…”