Effect of water temperature on the size-age structure of the population of <i>Hydrobia acuta</i> Black Sea molluscs and on invasion with <i>Gynaecotyla adunca</i> parthenitae

In the present work, the influence of water temperature on the size-age structure and size of the population ofHydrobia acutamolluscs and their invasion with parthenites of the microphallid trematodeGynaecotyla aduncain Kazachya Bay (Black Sea) was studied. A positive correlation between the indicators of invasion extensity and the size, abundance of molluscs and water temperature was revealed. It was found that the seasonal dynamics ofG. aduncaparthenites abundance clearly distinguishes the periods of mass infesction of molluscs, which are graphically displayed by two peaks – in July and November. It was confirmed that the life cycle of the Black Sea molluscsHydrobia acutaproceeds similarly to that of Mediterranean individuals