[Microsporidians (Protozoa, Microsporidia) of lower crustaceans from the reservoirs of Leningrad Province].

18 species of microsporidians were found in crustaceans of the Leningrad region. Of them 6 are referred to known species, 7 are described as new ones and 5 are identified to the genus. Some preliminary data are given on the influence of microsporidians on the host population, their specificity and variability.