[Adaptibility of Diplostomum cercariae in carp and the effect of a prior infestation].

Experiments on the infection of carp fry with cercariae of Diplostomum have shown that cercariae of Diplostomum spathaceum can penetrate crystalline lens of larvae of these fishes in three days after their hatching and that the adaptability of cercariae of D. paracaudum to carp is much higher than that of cercariae of D. spathaceum. After the first infection with cercariae a relative postinfectious immunity against infection with cercariae of this or close species of this genus arises in carp fry.