Radix (Radix) euphratica (Mousson, 1874)

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

publication ID	https://dx.doi.org/10.3897/zse.96.52860
publication LSID	lsid:zoobank.org:pub:B8CF4E84-1FEE-46F3-B275-BAFA6824902B
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scientific name	Radix (Radix) euphratica (Mousson, 1874)
status

Treatment

4. Radix (Radix) euphratica (Mousson, 1874) Figs 3F-H View Figure 3 ; 5C View Figure 5 . Table 1 View Table 1

Limnaea euphratica Mousson 1874: 40, 41.

Limnaea tenera race euphratica - Annandale and Prashad 1919b: 113, pl. XIII, figs 3-5.

Limnaea gedrosiana Annandale and Prashad 1919a: 48, pl. VII, figs 2-4; Annandale and Prashad 1919b: 107.

Limnaea gedrosiana var. rectilabrum Annandale and Prashad 1919a: 49, pl. VI, figs 1-6

Limnaea iranica Annandale and Prashad 1919a: 43, pl. VII, fig. 1.

Lymnaea gedrosiana - Likharev and Starobogatov 1967: 171, fig. 3.

Lymnaea (Pseudosuccinea) gedrosiana - Annandale and Rao 1925: 172; Subba Rao 1989: 130, fig. 295.

Lymnaea (Pseudosuccinea) gedrosiana f. rectilabrum - Annandale and Rao 1925: 173.

Lymnaea (Pseudosuccinea) iranica - Annandale and Rao 1925: 172.

Lymnaea (Radix) euphratica - Kruglov and Starobogatov 1993a: 88, fig. 12F; Kruglov 2005: 273, figs 160, 163.

Lymnaea (Radix) gedrosiana - Kruglov and Starobogatov 1993a: 90, fig. 14A; Kruglov 2005: 284, figs 164(8), 176.

Lymnaea (Radix) rectilabrum - Kruglov and Starobogatov 1993a: 90, fig. 13G; Kruglov 2005: 283, figs 164(7), 175.

Radix gedrosiana gedrosiana - Glöer and Pešić 2012: 42.

Radix gedrosiana rectilabrum - Glöer and Pešić 2012: 42.

Radix euphratica - Aksenova et al. 2018a: 4.

Radix (Radix) euphratica - Vinarski and Kantor 2016: 321.

Radix (Radix) gedrosiana - Vinarski and Kantor 2016: 322.

Radix (Radix) rectilabrum - Vinarski and Kantor 2016: 324.

Radix euphratica - Glöer 2019: 239, fig. 298.

TL.

Iraq, vicinity of Es-Samava Town (approximately 31°19'00"N, 45°17'00"E).

Types.

Not traced, but probably in the Zürich Zoological Museum ( Vinarski and Kantor 2016).

We recorded R. euphratica genetically from such remote countries as Iraq and Turkey in the west and southwest and Tajikistan in the northwest, also it has been identified from samples collected in the Krasnodar Region of Russia and Georgia ( Aksenova et al. 2018a; see Fig. 5C View Figure 5 ). The records of this species in literature cover also Afghanistan, India, Iran, Pakistan, Azerbaijan, Tajikistan, Uzbekistan and Turkmenistan (Annandale and Rao 1919a, b; Likharev and Starobogatov 1967; Subba Rao 1989; Kruglov and Starobogatov 1993a; Glöer and Pešić 2012). The range of R. euphratica seems to be rather wide, stretching from the Middle East to northern India. The northernmost localities of this snail are known in the Caucasian region, in Georgia and European Russia ( Aksenova et al. 2018a).

Conchologically, R. euphratica may be distinguished from the species of Radix described above by its relatively oblong ovate-conical shell, with high spire and weakly-inflated body whorl. The maximum shell height is around 20.0 mm (see Table 1 View Table 1 ). The columellar depression is weakly developed and, in some specimens, may be not visible. The tangential line of spire is almost straight or weakly concave that allows us to distinguish this species from the three species of Radix discussed above (see Fig. 3 View Figure 3 ). The morphology of the copulatory apparatus is typical for the genus (see Fig. 4 View Figure 4 ).

Nomenclature remark.

Several nominal species of radicines, with type localities situated in the Middle East or the east of Central Asia, were described in the late 19th - first half of the 20th century. The oldest of them are Limnaeus tener Küster, 1862, Limnaea auricularia var. persica Bourguignat in Issel, 1865 and Limnaea euphratica Mousson, 1874. The types of L. tener are lost, while the holotype of L. auricularia var. persica is extant ( Sitnikova et al. 2012). L. tener and L. auricularia var. persica share the same shell shape; these are ear-shaped, with low spire and enlarged aperture (see Fig. 5A, B View Figure 5 ). Both species were described from Iran and their conchological similarity, as well as the overlap in geographical distribution, may indicate these forms are conspecific (or represent the intraspecific morphs of R. auricularia ). Though the type series of R. euphratica is most probably lost, the shells of this species collected in Iraq ( NHMUK) look like shells of snails from Tajikistan studied by us both genetically and morphologically (compare Fig. 3F, G View Figure 3 and 3I View Figure 3 ). It allowed us to select the name Limnaea euphratica Mousson, 1874 for designation of this species, since the shell habitus of both L. tener and L. auricularia var. persica is different from that of snails from Iraq.

The absence of shell picture in the original description of L. euphratica (Mousson, 1874) may be compensated by the author’s remark that the shell shape of this species "approaches … some species of the eastern India [such as] L. succinea Desh." ( Mousson 1874: 40). Hubendick (1951) regarded L. succinea as a synonym of Lymnaea luteola , whose habitus indeed resembles that of L. euphratica , but looks rather different from shells of either L. tener or L. auricularia var. persica .

Based on the original descriptions and the study of specimens from available museum collections ( ZISP, NHMUK, NMNH and NHMW), we consider the three taxa from the Middle East, described by Annandale and Prashad (1919), as junior synonyms of R. euphratica . These are Limnaea gedrosiana , L. gedrosiana var. rectilabrum and L. iranica (see Fig. 5D-H View Figure 5 ). These three species are conchologically very similar and their shell traits correspond well to R. euphratica from Iraq (see Fig. 3I View Figure 3 ). Specimens of Radix rectilabrum sensu Kruglov and Starobogatov 1993a from Tajikistan and Uzbekistan studied by us ( Aksenova et al. 2018a) proved to be genetically indistinguishable from snails sampled in Iraq.

The taxonomic identity of Limnaea tenera and conchologically similar species ( Limnaea persica , Limnaea cor Annandale et Prashad, 1919) needs a further research by means of an integrative taxonomic analysis of the topotypic specimens.

Kingdom	Animalia
Phylum	Mollusca
Class	Gastropoda
Order	Hygrophila
Family	Lymnaeidae
Genus	Radix