[Demographic development of Lymnaea (Galba) truncatula Müller in Haute-Vienne, France. About observations on 4 years (1973-1976) (author's transl)].

Notes on the influence of shallow drainage and predation by Zonitoides nitidus on Lymnaea truncatula populations in 4 types of habitats. The populations of snails are observed with large and perceptibly constant numbers by the regular maintenance of drainage. Irregular maintenance is followed by a gradual fall of numbers of snails with their rapid increase in the year following autumnal ditch-digging. Grass-mowing of swampy meadows at the beginning of summer drying distinctly restricts numbers of snails, when Zonitoides nitidus lives in the habitats.