[Problem of pathogenesis of somatic gigantism in snails infected with developmental stages of digenetic trematodes]

Mechanism of pathogenesis of somatic gigantism of water snails infected with development stages of digenetic trematodes is a complex phenomenon. The manner of origination of these abnormalities is often dependent on accepted host-parasite relationship. In the article there are discussed essential foundations of hypotheses explaining snails' parasitological gigantism as a consequence of alterations in gonadal activity (e.g. the hypothesis of disturbances in energetic budget of a host) or of different aspects of the parasite effect on activity of the neurosecretory centres, involved in the control of somatic growth, as well as a possibility of production by parthenites some compounds, acting synergically with host's growth neurohormone.