Planorbarius corneus (Linnaeus, 1758) (fig. 3, 12, 13)

Distribution. In the Transcarpathian Region P. corneus is apparently one of the common and widespread species — we found its populations in 8 localities: 6–8, 13, 15, 22, 23 and 32 (fig. 1, table 1). In Ukraine P. corneus is registered in all regions (Anistratenko, Сhernogorenko, 1989; Stadnichenko, 1990); it was listed also in Transcarpathian (Zdun, 1960; Stadnichenko, Gyrin, 2011 a; Anistratenko et al., 2018). Global distribution — Europe and the Western Siberia (Vinarski, Kantor, 2016).

Remarks. In the Transcarpathia this species usually inhabits shallow zone of permanent lotic and lentic waterbodies within the altitude range 100–170 m a. s. l. mostly associating with macrophytes; it also occurs in small natural and artificial ponds (table 1, 2). Apart the P. corneus, Stadnichenko and Gyrin (2011a) reported in the Transcarpathia fauna also P. purpura (O. F. Müller, 1774) and P. grandis (Dunker, 1850) . Conchologically both P. purpura and P. grandis can be differentiated from P. corneus; however, Western European malacologists do not recognize the former taxa as distinct species and regard them as junior synonyms of P. corneus (Glöer, 2002; Welter-Schultes, 2012).