Segmentina montgazoniana Bourguignat in Servain, 1881 (fig. 4, 18–20)

D i s t r i b u t i o n. In the Transcarpathia S. montgazoniana is registered for the first time and is a formally new species for the regional fauna. Currently its populations are found in two localities: 6 and 7 (fig. 1, table 1). In Ukraine S. montgazoniana is known from the Polissya and Forest-Steppe zones (Anistratenko, Chernogorenko, 1989; Stadnichenko, 1990). Global distribution — Europe (Vinarski, Kantor, 2016).

Remarks. In the Transcarpathia S. montgazoniana occur in shallow permanent waterbodies (rivers and their floodplains) on vegetation within the lowland area (ca. 100 m a. s. l.) (table 1, 2). European authors usually consider diversity of Segmentina as confined to one morphologically variable species, S. nitida (Falkner et al., 2001; Glöer, 2002; Welter-Schultes, 2012). However, some anatomical and conchological differences allow distinguishing among this group several separate species (Kruglov, Soldatenko, 1997) of which S. montgazoniana is recorded in the studied region.