[Infestation of littoral molluscs of Dal'nie Zelentsy Bay by parthenitae of the eider parasite Microphallus pygmaeus (Levinsen, 1881) (Trematoda: Microphallidae)].

The mollusks Littorina saxatilis, L. obtusata, Solariella obscura, Cingula aculeus, Hydrobia ulvae, Margarites helicina and M. groenlandica serve as hosts of the parthenites of Microphallus pygmaeus in eastern Murman. Over a period of 20 years the infection rate of the mollusks has increased greatly that is associated with the increasing number of definitive hosts. Maximum infection rate was recorded in the end of July--August. The infection rate of littorins within this period was about 90 per cent.