Effect of Trematoda Infestation and Zinc Ions of the Aquatic Medium on Hemocytes and Some Hematological Characteristics of Planorbarius purpura (Mollusca: Gastropoda: Pulmonata: Bulinidae)
Pettancyclus australicus (Tate) (Bulinidae, Miratestinae) ?????????????? ?????????????????? ???? ??????????????