Bithynia troschelii (Paasch, 1842)

Anistratenko, V. V., Furyk, Yu. I., Anistratenko, O. Yu. & Degtyarenko, E. V., 2019, A Review Of Species Diversity, Distribution And Ecology Of Freshwater Gastropod Molluscs Inhabiting The Ukrainian Transcarpathian, Vestnik Zoologii 53 (5), pp. 349-374 : 360

Bithynia troschelii (Paasch, 1842) ( fig. 3 , 6)

Distribution.The species is distributed throughout Europe and almost all West Siberia ( Beriozkina et al., 1995). In some parts of its range it is rare or very rare (e. g. in Poland, Falniowski et al., 2004). In Ukraine the species is known from limited number of locations in the west part and in Steppe zone of the country (e. g. Anistratenko, Chernogorenko, 1989; Anistratenko, Stadnichenko, 1995). Recently it was mentioned as regionally new species for the Transcarpathian Region of Ukraine ( Anistratenko et al., 2018). Since B. troschelii is recorded here only one time (locality 13) we suggest it is rare species in the Ukrainian Transcarpathia.

R e m a r k s. Some authors (e. g. Welter-Schultes, 2012) use the name Bithynia transsilvanica (Bielz) for this species while others ( Glöer, 2002; Falniowski et al.,2004) consider the valid name is B.troschelii .In 1995 Beriozkina et al.(1995) established a distinct generic name Opisthorchophorus for Paludina troschelii Paasch, 1842 and few others nominal species with peg-top-shaped shell having convex whorls separated by a deep suture. By the shell shape the specimens we found in Transcarpathia ( fig. 3 , 6) demonstrate a close resemblance to ‘ O. hispanicus’ sensu Beriozkina et al.(1995: fig.4 , E).However we are not sure if ‘ O. hispanicus’ might represent a distinctinct species or is just a morphotype and prefer name the snails found as B. troschelii . As in the whole area of its distribution the species lives in Transcarpathia in temporary and semipermanent waterbodies, e.g. in small shallow artificial pools.

Figures

Fig. 3. Shells of Transcarpathian gastropod molluscs: 1 — Viviparus viviparus (locality 12); 2 — Contectiana contecta (locality 15); 3 — Viviparus sphaeridius (locality 12); 4 — Bithynia tentaculata (locality 15); 5 — Valvata (Cincinna) ambigua (locality 15); 6 — Bithynia troschelii (locality 13); 7 — Valvata (Cincinna) piscinalis (locality 22); 8 — Lithoglyphus naticoides (locality 9); 9–11 — Planorbis planorbis (locality 15); 12, 13 — Planorbarius corneus (locality 15). Scale bars are given for 1–3, 4–8, and 9–13 correspondingly.

Fig. 4.Shells of Transcarpathian gastropod molluscs: 1 — Radix peregra (locality 55); 2 — R. lagotis (locality 48); 3–5 — Physa acuta (3, 4—from locality 6; 5 — locality 15); 6–8 — Anisus septemgyratus (locality 58); 9–11 — Anisus spirorbis (locality 16); 12–14 — Gyraulus albus (locality 16); 15–17 — Segmentina nitida (locality 14); 18–20 — S. montgazoniana (locality 7); 21–23 — Ancylus fluviatilis (locality 58).