Badania nad behawiorem slimakow w antropogenicznie zmienionym srodowisku wodnym. 1. Aktywnosc lokomotoryczna Lymnaea stagnalis [L.] ze szczegolnym uwzglednieniem subpopulacji zarazonych przez stadia rozwojowe przywr digenetycznych

Studies upon behariour of snails in anthropogenically changed water environment. 1. Locomotor activity of lymnaea stagnalis (L), with regard to subpopulations infected with developmental stages of digeneans. The aim of the paper was to analyse the locomotor activity of snails, Lymnaea stagnalis, with regard to physico-chemical properties of water in an inhabited reservoir and parasitic infection. The material was collected in selected anthropogenic water environments situated in the Upper Silesian Industrial Region (sinkhole ponds, sand-and clay-excavations). The locomotor activity of each snail was analysed in laboratory conditions by designation of number of penetrated segments, marked in tanks filled with water originating from a given reservoir, during 15', with intervals of l'. It was observed the significant relationship between locomotor activity of examined snails and the water carbonaceous hardness (r = -0,812, at range of the independent variable 173.0-863.5 mg CaCO₃/dm³). Correlation coefficients with other physico-chemical parameters of water were close to zero. Locomotion of snails infected with developmental stages of digenetic trematodes was significantly lower comparing to non-infected individuals. Locomotor activity of these former ones was dependend more on degree of the digestive gland damage by the parasite than on the infection agent.