Bythinella sp.

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 : 360-361

Bythinella sp.

Distribution. Spring snails of Bythinella occur throughout continental Europe (e. g. Wilke et al., 2010). Two nominal species of the genus are reported in Ukraine from the Transcarpathian and Ivano-Frankivsk Regions so far: B. austriaca (Frauenfeld, 1857) and B. hungarica Hazay, 1881 (e. g. Zdun, 1960; Anistratenko, Stadnichenko, 1995), however, these identifications need additional confirmation. The data available suggest the distribution of Bythinella in Transcarpathia is strictly limited to a few localities. We recently found individuals of Bythinella with no clear specific determination in small stream flowing into the Synyavka River near Osiy village ( Anistratenko et al., 2017: shell image is given in fig. 3 , G, H) and later it was recorded also in the stream near Bukove village ( fig. 1 , localities 19 and 20 correspondingly).

R e m a r k s. Identification of spring snails of the genus Bythinella is usually difficult due to lack of conchological characteristics which can serve as the reliable features for species distinguishing. For instance, several species of Bythinella were recently revealed in Ignis Mountains, the region of Rumania adjacent to the Ukrainian Transcarpathia ( Falniowski et al., 2009), clearly distinguishing genetically though are very similar to each other in shell morphology. Moreover, the representatives of Bythinella can hardly be distinguished from conchologically similar and somewhere in the Transcarpathian area sympatric occurring species of the genus Terrestribythinella ( Anistratenko et al., 2017) . No doubts that current taxonomy of these groups and study of their relationhips requires involving of a combination of morphological and genetic evidences. Populations of Bythinella in Transcarpathia occur in the altitude range of 200–400 m a. s. l. (table 2) in the rapid flow cold water with a stone bottom, which is typical for the preferred living conditions of these snails. Together with Bythinella sp. also Terrestribythinella baidashnikovi and some species of pulmonate were sampled in the biotopes ( table 1 ).

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. 1. Map showing the localities of samples studied. Details for each sampling point are given in table 1.