WATERBODY FLOWAGE AND ITS EFFECTION ON MOLLUSKS CONTAMINATION UNDER THE CONDITIONS OF UKRAINIAN POLISSYA STREAMFLOWS

The research results on the effect of water flowage of different current speed on the mollusks contamination have been presented in the paper. There is limited data in literature as to the effect of current speed on mollusks contamination under contemporary conditions of Ukrainian Polissya. The presented information broadens and complements the data. The current speed proved to indirectly affect the level of mollusks contamination by larvae stage of trematodes. It was stated that in streamflows with oligotype (0 – 0,1m/s) and mesotype (0,1 – 1m/s) current speeds the infection extensity of some mollusks species by parthenita and trematodes larvae may vary in wide range. It should be noted, that there were no rivers of polytype current speed in the studied waterbody. The high infection extensity indices by parthenita and trematodes larvae were revealed in Bithynia tentaculata mollusks (Linnaeus, 1758), Viviparus (Viviparus) viviparus (Linnaeus, 1758) in the Uzh, the Revna, the Seim under oligotype and mesotype current speed. This testifies to the fact, that contamination of the above mollusks types does not essentially depend on the current speed. We consider it is caused by high density of their population and the number of definite hosts. The above mentioned mollusks are the bridging hosts of trematodes which complete their development mainly in birds and fishes. The current speed is determinative as to contamination of widely distributed mollusks species as Lymnaea stagnalis (Linnaeus, 1758) and Planorbarius corneus (Linnaeus, 1758) which are stagnophiles. The comparison of infection extensity of joint river mollusks selection with oligotype and mesotype current speeds has been conducted.