“…The species Ulnaria acus (Kützing) Aboal was chosen as the object of study, which is a cosmopolitan species living in freshwater bodies of Eurasia (Aboal et al, 2003;Medlin et al, 2008;Kulikovskiy et al, 2016;Kahlert et al, 2019;Liu et al, 2019;Podunay et al, 2021). U. acus was found in water bodies in North America (Eberle, 2008;Smith, 2010;Bergey et al, 2017), South America (Vouilloud, 2003;Crossetti and Bicudo, 2008), as well as in other regions (Sherwood, 2004;Bostock and Holland, 2010;Marazzi, 2014;Khairy et al, 2017).…”