| haplometra cylindracea (zeder, 1800) (trematoda:plagiorchiidae): variation in the dates of cercarial shedding for overwintering galba truncatula. | natural infections of galba truncatula with haplometra cylindracea were followed from 2001 to 2009 to determine if their characteristics were similar when snails came from water collections frequented by bufo bufo or by frogs and newts for their egg-laying. snail samples were collected from both types of sites to count shed cercariae for three days and also free cercariae when snails were dissected. in sites only frequented by b. bufo, cercarial shedding occurred earlier than in those colonized ... | 2011 | 21678794 |