[Distribution and biology of Apatemon annuligerum (V. Nordmann, 1832) Odening, 1970 (Trematoda, Strigeidida)].

In Lake Itkul situated north-westwards of the town of Abakan there were found encysted metacercariae of Apatemon annuligerum in the eyes of the perch. Adult fishes are 100% infected, the infection intensity amounting to 28 to 455 cysts (125 on the average). Maximum infection of the perch takes place at the age of 4 to 5 years. In elder fishes proceeds a decrease of infection intensity on account of a considerable mortality of cysts. There was undertaken an infection of incubative ducklings and observed a development of marita to a mature state. The maturation of eggs takes place on the 5-th day.