Radix (Radix) auricularia (Linnaeus, 1758)

Vinarski, Maxim V., Aksenova, Olga V. & Bolotov, Ivan N., 2020, Taxonomic assessment of genetically-delineated species of radicine snails (Mollusca, Gastropoda, Lymnaeidae), Zoosystematics and Evolution 96 (2), pp. 577-608 : 577

1. Radix (Radix) auricularia (Linnaeus, 1758) Figs 3A ; 4A.

Helix auricularia Linnaeus 1758: 774, 775.

Lymnaea auricularia - Hubendick 1951: 151, figs 96, 97, 99 (partim).

Lymnaea (Radix) auricularia - Kruglov and Starobogatov 1993a: 85, fig. 10E; Jackiewicz 1998: 47, figs 64, 65, pl. II, X.7, XI, 1, 2; Kruglov 2005: 250, figs 137(1)-139; Andreeva et al. 2010: 99, fig. 48.

Lymnaea (Radix) hadutkae Kruglov and Starobogatov 1989: 22, figs 1(12), 2(7); 1993a: 85, fig. 11D.

Lymnaea (Radix) hakusyensis Kruglov and Starobogatov 1989: 20, figs 1(8), 2(6); 1993a: 88, fig. 11G.

Lymnaea (Radix) thermobaicalica Kruglov and Starobogatov 1989: 20, figs 1(10), 2(8); 1993a: 85, fig. 11E.

Lymnaea (Radix) thermokamtschatica Kruglov and Starobogatov 1989: 22, figs 1(9), 2(9); 1993a: 85, fig. 11F.

Radix auricularia - Glöer 2002: 213, fig. 241; Welter-Schultes 2012: 52, textfig; Vinarski and Kantor 2016: 318; Aksenova et al. 2016: 16, figs 1F, G; 2; Glöer 2019: 236, fig. 294.

TL.

Europe.

Types.

Possibly lost ( Vinarski and Kantor 2016).

This species is common in Eurasia, sporadically distributed in North Africa, introduced into North America and New Zealand ( Hubendick 1951; Charleston and Climo 1979; Burch 1989; Brown 1994; Kruglov 2005; Andreeva et al. 2010). It has many times been characterised in literature, both conchologically and anatomically ( Jackiewicz 1998; Glöer 2002; Kruglov 2005). The typical form of this snail has an ear-shaped shell with shortened spire and greatly expanded body whorl (see Fig. 3A ). However, R. auricularia exhibits wide variation is shell shape and proportions ( Vinarski 2016b). It may form local and ecological races, including dwarf races of geothermal springs, which had been accepted as valid species ( Bolotov et al. 2014; Aksenova et al. 2016, 2017).

The structure of the copulatory apparatus of R. auricularia is quite typical for the genus. The praeputium is oblong, cylindrical and rather thick; its width is virtually equal along its whole length (see Fig. 4A ). The penis sheath is much narrower, with a bulbous swelling on its distal end. The lengths of the praepuptium and the penis sheath of R. auricularia are nearly equal, though in some populations, there is a substantial variation in the ICA values ( Vinarski 2011).

A characteristic trait of this species, which distinguishes it from the remaining radicines of Europe, is the presence of freckles on the foot and praeputium ( Glöer 2019).

Figures

Figure 3. Shells of species in the genus Radix. A. Radix auricularia (28.08.2013, Kazakhstan, Karaganda Region, Suresai River; LMBI); B. R. alticola (20.06.2012, Tajikistan, a hot spring near Djelandy village; LMBI); C. R. alticola (01.07.2016, Tajikistan, a warm brook near Dzhaushangoz village; LMBI); D. R. brevicauda (Kashmir, a syntype; NHMUK); E. R. brevicauda (05.08.1948, Tajikistan, Pamir Mts., Shaimak village, in a warm spring; ZISP); F. R. euphratica (26.06.2016, Tajikistan, Dushanbe, a fountain near the President's palace; LMBI); G. R. euphratica (04.07.2016, Tajikistan, a roadside ditch near Kurban-Shakhid village; LMBI); H. R. euphratica (without date, Iraq, Bagdad; NHMUK); I. R. makhrovi, the holotype (China, Tibet, a roadside ditch west of the Lhasa River mouth; ZISP); J. R. plicatula, a probable syntype (China, Chusan, NHMUK); K. R. plicatula (26.07.2017, China, Uyghuria, Bagrash-kol' Lake; LMBI); L. R. plicatula (26.11.2014, China, Bejing, an artificial pond in the former Emperor's summer palace; LMBI). Scale bars: 2 mm (B-C, F-L), 5 mm (A, D-E, K).

Figure 4. Copulatory apparatuses of the species of the genus Radix. A. Radix auricularia (19.07.2007, Russia, Tyumen' Region, Vylposl channel near Labytnangi Town); B. R. alticola (01.07.2016, Tajikistan, a warm brook near Dzhaushangoz village); C. R. euphratica (04.07.2016, Tajikistan, a roadside ditch near Kurban-Shakhid village); D. R. makhrovi, a paratype (after Aksenova et al. 2018 a, modified). E. R. plicatula (26.11.2014, China, Bejing, an artificial pond in the former Emperor's summer palace). F. R. rubiginosa (Malaysia, Kuala-Lumpur); G. R. rufescens (24.11.2016, Myanmar, Yetho River, near the dam). H. R. natalensis (05.08.2018, Uganda, crater lake Kyamwiga). Scale bars: 2 mm.