The presence of predators modifies the larval development of Fasciola hepatica in surviving Lymnaea truncatula.
Experimental infections of Lymnaea truncatula with Fasciola hepatica were performed to study the consequences of the presence of predators (sciomyzid larvae or zonitid snails) on the characteristics of larval F. hepatica development in surviving snails. Controls consisted of infected snails that were not subjected to predators. Compared to controls, the survival rate at day 30 post-exposure, the duration of cercarial shedding, and the number of cercariae shed by surviving snails were significantly lower when predators were present in snail breeding boxes, whatever the type of predator used. In contrast, the prevalences of Fasciola infections in snails, and the length of time between exposure and the onset of cercarial shedding showed no significant variation. The progressive development of a stress reaction in surviving snails against predators during the first 30 days of experimental exposure to F. hepatica would influence snail survival during the cercarial shedding period and, consequently, the number of cercariae shed by the snails.
Rondelaud
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D
UPRES EA no. 3174, Facultés de Médecine et de Pharmacie, 2 rue du Docteur Raymond Marcland, 87025 Limoges Cedex, France. rondelaud@pharma.unilim.fr
Vignoles
P
P
Dreyfuss
G
G
D000818:Animals; D004175:Diptera; D005210:Fasciola hepatica / Q000254:growth & development*; D005211:Fascioliasis / Q000469:parasitology*; D020387:Food Chain; D006790:Host-Parasite Interactions; D007814:Larva / Q000254:growth & development; D008195:Lymnaea / Q000469:parasitology*; D012908:Snails; D013312:Stress, Physiological / Q000469:parasitology*