Radix auricularia (Linnaeus, 1758)

Bolotov, Ivan, Bespalaya, Yulia, Aksenova, Olga, Aksenov, Andrey, Bolotov, Nikita, Gofarov, Mikhail, Kondakov, Alexander, Paltser, Inga & Vikhrev, Ilya, 2014, A taxonomic revision of two local endemic Radix spp. (Gastropoda: Lymnaeidae) from Khodutka geothermal area, Kamchatka, Russian Far East, Zootaxa 3869 (5), pp. 585-593 : 586-588

Radix auricularia (Linnaeus, 1758)

( Figs. 1–7 , Table 1 )

Lymnaea (Radix) hadutkae Kruglov & Starobogatov, 1989 syn. n.: 22, figs. 1.12 & 2.7; Kruglov & Starobogatov, 1993: 85, fig. 11D

Lymnaea (Radix) thermokamtschatica Kruglov & Starobogatov, 1989 syn. n.: 22, figs. 1.9 & 2.9; Kruglov & Starobogatov, 1993: 85, fig. 11E

Material examined. Holotype of Lymnaea (Radix) hadutkae ( ZIN), Kamchatka: “Khodutkinskiy hot spring, gradient t° = 15–41°[C], opt. ~ 25–27°[C], 8.ix.1979, N.N. Khmeleva leg.” (no. 510–1982). Holotype of Lymnaea (Radix) thermokamtschatica ( ZIN), Kamchatka: “Khodutkinskiy hot spring, gradient t° = 15–41°[C], opt. ~ 25–27°[C], 8.ix.1979, N.N. Khmeleva leg.” (no. 510–1982). Topotypes ( INEP), 31 specimens, Kamchatka: Khodutka geothermal area, warm lake and warm river source, 6th June 2013, Aksenova, Bespalaya & Bolotov leg. ( INEP). Kamchatka: 6 specimens, Paratunskie hot springs, 8th June 2013, Aksenova, Bespalaya & Bolotov leg.; 7 specimens, Malkinskie hot springs, 3rd July 2012, Bespalaya, Bolotov & Vikhrev leg.; 4 specimens, Plotnikova River (Bolshaya River Basin), 3rd July 2012, Bespalaya, Bolotov & Vikhrev leg. ( INEP). Kurile Archipelago: 9 specimens, Kunashir Island, Aliger Lake, 27th July 2011, Bespalaya & Aksenova leg. ( INEP). Sakhalin Island: 2 specimens, Tym River, 14th June 2012, Bespalaya, Bolotov & Vikhrev leg. ( INEP). Primorye: 3 specimens, a small pond near Razdolnaya River, 25th June 2012, Bespalaya, Bolotov & Vikhrev leg; 4 specimens, Ussuri River (Amur River Basin), 20th June 2012, Bespalaya, Bolotov & Vikhrev leg. ( INEP). Locality coordinates are given in Appendix 1.

Description. Specimens from the Khodutka geothermal area are very small with shell height 7.0– 14.6 mm, width 4.0– 9.5 mm. Shell is glossy, dark-yellow or light brownish, elongated, with 4 whorls enlarging slowly ( Figs. 1–3 ). The spire is long, widely conical, in adult shells often destroyed on the top (likely due to the geothermal water influence). The aperture is ear-shaped, relatively narrow with an angle of 90° or>90° on the top. The inner lip is folded at the columella, with weakly-sinuated fold. The foot and dorsal part of the preputium bear “freckles”. The bursa copulatrix is oval or rounded; the bursa duct is thin and very long or long ( Figs. 1–3 and Table 1 ). According to morphological and anatomical data, specimens from other localities of the Russian Far East are similar to those found from the Khodutka area ( Fig. 4 ). However, specimens from non-geothermal localities (Plotnikova River, Aliger Lake, a pond near Razdolnaya River and Ussuri River) are larger with shell height up to 25.7 mm, width up to 20.9 mm, and had a more compact shell shape with a wide aperture.

Remarks. Both of the endemics from the Khodutka geothermal area ( Fig. 6 ) are conspecific to R. auricularia , based on morphological, anatomical and molecular studies ( Table 1 and Figs. 1–5 ). The same elongated shells with narrow apertures were reported for several R. auricularia populations from the Baikal Lake area ( Stift et al. 2004). According to our data, R. auricularia is widespread on the Russian Far East, where it was recorded from Kamchatka, Primorye, Sakhalin, and Kuriles ( Fig. 7 ). Zhadin (1952) reported that this species is widespread on the Pacific Basin, including Kamchatka, Amur Basin and Primorye, which is in agreement with our records. However, Kruglov & Starobogatov (1993) noted that R. auricularia ranged in Europe, the western part of the Middle East and Siberia, but not mentioned in the species records from the Far East. Thereafter, Starobogatov et al. (2004) again reported that species ranged on the Far East, where it was recorded in rivers of the Pacific coast from Kamchatka to Primorye. Meanwhile, Kruglov & Starobogatov (1989, 1993), Starobogatov et al. (2004) and Kruglov (2005) listed many local endemic Radix species for different areas of the Russian Far East, which belong to the sections Ussuriradix Kruglov & Starobogatov, 1989 , Nipponiradix Kruglov & Starobogatov, 1989 and Okhotiradix Kruglov & Starobogatov, 1989 . Taxonomic position of these taxa is uncertain and they need in a current revision based on mitochondrial and nuclear molecular markers.

Figures

FIGURES 1 – 7. Radix auricularia (Linnaeus, 1758) from Russian Far East. Figs. 1 - 4. Shell and proximal part of the female genitalia. Scale bar 2 mm. Fig. 1. Holotype of Lymnaea (R.) hadutkae Kruglov & Starobogatov, 1989 syn. n. (shell photo: M. V. Vinarski; genitalia redrawn from the protologue, Fig. 2.7). Fig. 2. Holotype of L. (R.) thermokamtschatica Kruglov & Starobogatov, 1989 syn. n. (shell photo: M. V. Vinarski; genitalia redrawn from the protologue, Fig. 2.9). Fig. 3. Newly collected specimen from the Khodutka geothermal area, Kamchatka (photos: O. V. Aksenova). Fig. 4. Specimen from Malkinskie hot springs, Kamchatka (photos: O. V. Aksenova). Fig. 5. Bayesian phylogram of haplotypes based on mitochondrial COI gene dataset (Appendixes 1 & 2). The scale bar indicates the branch length. Asterisks: Posterior probabilities ≥ 0.95; other significant node support values are mentioned in the figure. Haplotypes exclusively from NCBI’s Genbank are marked with circumflex accents (˄). The well-supported clade with two haplotypes from the Khodutka geothermal area is highlighted in blue. Fig. 6. General view of the Khodutka warm lake. Fig. 7. Map of observed localities on the Russian Far East. The red circles represent species records. Locality codes are given in Appendix 1. The digital elevation model and other layers of the map were added from Esri Data & Maps 10 dataset (Map: M. Yu. Gofarov).

Tables

TABLE 1. The comparison of type specimens of endemic Lymnaea (Radix) species from Khodutka geothermal area with R. auricularia based on morphological and anatomical distinguishing features (Glöer & Pešić 2008)

Species	Region and reference	Aperture ear-shaped	Upper margin of aperture (frontal view)	Upper margin of aperture (apical view)	Juveniles look like the adults	Bursa duct	“Freckles” on foot and preputium
R. auricularia	Southern Europe (Glöer & Pešić 2008)	yes	90º or>90º	straight	no	very long	yes
R. auricularia	Russian Far East, excluding Khodutka area (our data, list of localities see. in “Material examined”)	yes	90º or>90º	straight	no	very long	yes
R. auricularia	Khodutka area, Kamchatka (our data)	yes	90º or>90º	straight	no	very long or long	yes
Holotype of L. (R.) hadutkae	Khodutka area, Kamchatka (Kruglov & Starobogatov 1989; Kruglov 2005; our data)	yes	90º	straight	--	very long	no data
Holotype of L. (R.) thermokamtschatica	Khodutka area, Kamchatka (Kruglov & Starobogatov 1989; Kruglov 2005; our data)	yes	>90º	straight	--	long	no data