References Bauer, O. N. 1984. Biological basis of aquaculture: parasites and diseases of fi sh. Nauka, Moscow, 1-170 [In Russian]. Bikhovskaya-Pavlovskaya, I. E. 1985. Parasites of fi sh: Study Guide. Nauka, Leningrad, 1-121 [In Russian]. Davidov, O. N., Tymnichanov, Yu. D. 2003. Diseases of freshwater fi sh. Vetinform. Kiev, 1-219 [In Russian]. Henetsinska, T. A., Kosheva, A. F. 1959. On the question of the life cycle and the systematic position of Paracoenogonimusovatus Katsurada (Trematoda) and the identity of this species to Neodiplostomulum hughesi
This is the first review of life cycles of trematodes with parthenitae and larvae in freshwater gastropods from forest biocoenoses of Ukrainian Polissia. Altogether 26 trematode species from 14 families were found circulating in 13 ways in molluscs from reservoirs connected with forest ecosystems of the region. Three-host life cycle is typical of 18 trematode species, two-host life cycle has found in 7 species, and four-host cycles has found in one species. Alaria alata Goeze, 1782, has three-host (Shults, 1972) and four-host cycles. Opisthioglyphe ranae (Froehlich, 1791) can change three-host life cycle to two-host cycle replacing the second intermediate host () with the definitive host. Species with primary two-host life cycle belong to Notocotylidae Lühe, 1909, Paramphistomidae Fischoeder, 1901 and Fasciolidae Railliet, 1758 families. Trematodes with three-host cycle have variable second intermediate hosts, including invertebrates and aquatic or amphibious vertebrates. Definitive hosts of trematodes are always vertebrates from different taxonomic groups. The greatest diversity of life cycles is typical for trematodes of birds. Trematodes in the forest biocoenoses of Ukrainian Polissia infect birds in six ways, mammals in three, amphibians in four, and reptiles in one way. The following species have epizootic significance: Liorchis scotiae (Willmott, 1950); Parafasciolopsis fasciolaemorpha Ejsmont, 1932; Notocotylus seineti Fuhrmann, 1919; Catatropis verrucosa (Frölich, 1789) Odhner, 1905; Cotylurus cornutus (Rudolphi, 1808); Echinostoma revolutum (Fröhlich, 1802) Dietz, 1909; Echinoparyphium aconiatum Dietz, 1909; Echinoparyphium recurvatum (Linstow, 1873); Hypoderaeum conoideum (Bloch, 1782) Dietz, 1909; Paracoenogonimus ovatus Kasturada, 1914; Alaria alata Goeze, 1782.
 Ginetsinskaja, T. A., Dobrovolsky, A. A. (1963): [A new method of finding sensilla on trematodes larvae and its value for systematic]. Reports. AS of USSR, 151,2: 460–463 (In Russian)  Ginetsinskaja, T. A., Koscheva, A. F. (1959): [About the lifecycle and systematic status of Paracoenogonimusovatus Katsurada (Trematoda) and identity of metacercariae of this species with Neodiplostomum hughes Markewitsh]. Vestnik Leningradskogo universiteta, Vol. 2, No 9: 68–75 (In Russian)  Katsurada, F. (1914): Studien uber Trematoden bei SuBwasserfischen, mit
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the Vistula Lagoon ecosystem. Oceanologia, 48 (4), 545-561. Sarabeev, V. L., Domnich, I. F. 2001. Parasites of fishes of the family gobiidaein the north-western part of the Azov sea. In: Problems of ichthyopathology. UAAS, Kiev, 100-104 [In Russian]. Skryabin, K. I. 1952. Trematodes of animals and humans. AS USSR. Moscow, Vol. 6, 283-297 [In Russian]. Soroka, N., Goncharov, S. 2015. Method of allocation metacercariae trematodes Paracoenogonimusovatus; The applicant and patentee National University of Life and Environmental Sciences of Ukraine. No. 103347; 06