The source of the net zooplankton comes from Slovak/Hungarian stretch of the Danube River and its tributaries and from Východoslovenská nížina Lowland hydro melioration canal system. Out of 2400 samples, there were 13 new or in Slovakia rarely occurring species of rotifera found. All found species were in small quantities. The following species were found: Argonotholca foliacea (Ehrenberg, 1838), Brachionus falcatus Zacharias, 1898, Elosa worrallii Lord, 1891, Euchlanis triquetra Ehrenberg, 1838, Mytilina bisulcata (Lucks, 1912), Mytilina crassipes (Lucks, 1912), Mytilina compressa (Gosse, 1851), Mytilina trigona (Gosse, 1851), Paradicranophrus hudsoni (Glascott, 1893), Ptygura melicerta Ehrenberg, 1832, Testudinella caeca (Parsons, 1892), Testudinella pseudoeliptica Bartoš, 1951 and Testudinella truncata ecornis Wieszniewski, 1953.