Evolution of tissue lesions in Lymnaea truncatula infected by Muellerius capillaris and by Neostrongylus linearis (Nematoda: Protostrongylidae)

Abstract

Juvenile and adult Lymnaea truncatula, 1 and 4 mm in height, were exposed to L1 of Muellerius capillaris and of Neostrongylus linearis. They were raised at 23° C until day 35 post-exposure and batches of five survivors were killed at periodic intervals for histological studies. Different lesions were observed in all the snails with living or abortive larvae. An inflammatory reaction developed in the foot and in the tentacles. Epithelial necrosis, often followed by reconstitution, occurred in the four studied organs (albumen gland, digestive gland, gonad, kidney). The frequency of the different lesion types varied in relation to the protostrongylid species and to snail size at the time of exposure. Principal components analysis showed i) the association of the presence of N. linearis larvae with lesions of the digestive glands, and it) the association of the presence of M. capillarislarvae with foot lesions.