Trematode Parthenitae Infection Rate and Distribution of Kola Bay Actic Molluscs of the Genus Littorina
The study was carried out in 2018 in the littoral zone of Kola Bay during the autumn period in the areas of Abram Mys Settlement, Mishukovo Settlement and Retinskaya Bay. Molluscs of the genus Littorina were collected from various substrates: stones, algae, metal construction and soil. In addition, samples were taken not from a particular substrate, but along the borders of the littoral zone to study species composition of molluscs and common level of infection rate in study areas. Our data showed that L. saxatilis infested by mature trematode parthenitae prefer being on the surface of algae, metal structure, stones at low tide instead of hiding under the stones, in the thickness of algae and in other possible shelters. The study of age distribution among infested Littorina molluscs living on different substrates showed that the ratio of age groups is different and varies from 1+ to 13+. Distribution data are established and considered for infested molluscs by trematode parthenitae of the group ”pygmaeus”: Microphallus pygmaeus, M. piriformes, which are characterized by the absence of free-living cercariae. Trematode parthenitae of other species which have a stage of free-living cercaria in their life cycle are absent in molluscs during the autumn period.
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