Valvata (Cincinna) piscinalis (O. F. Müller, 1774) (fig. 3, 7)

Distribution. General distribution range of V. piscinalis covers the Europe, Caucasus (Armenia) and Western Siberia. In the Ukraine the species is widelydistributed in the Dnipro basin and in the mouth part of the Danube (Anistratenko, Anistratenko, 2001). Also V. piscinalis is reported in the Ukrainian part of Transcarpathia (Zdun, 1960; Stadnichenko, Gyrin, 2011 b; Anistratenko et al., 2018). We found these mollusc populations in 5 sites located mainly within the Tisa River basin: 11, 15, 21–23 (fig. 1, table 1).

Remarks. In the Transcarpathian this species inhabits slow-flowing waters within the lowland zone of the region in the altitude range between 100 and 150 m a. s. l. (table 2), Accordinig to our observations, V. piscinalis prefers hard (stony or sandy) substrates in shallow zone of rivers or, rarely, springs. In the Chorna Voda River (locality 15) these snails co-occurred with highly diverse community of gastropod molluscs (table 1).