Theodoxus jordani (G.B. Sowerby I, 1836)

Sands, Arthur F, Gloeer, Peter, Guerlek, Mustafa E, Albrecht, Christian & Neubauer, Thomas A, 2020, A revision of the extant species of Theodoxus (Gastropoda, Neritidae) in Asia, with the description of three new species, Zoosystematics and Evolution 96 (1), pp. 25-66 : 25

Theodoxus jordani (G.B. Sowerby I, 1836) Figures 15A-V , 16A-P , 17A-J

Neritina Jordani G.B. Sowerby I 1836: 4, pl. 99, fig. 49; G.B. Sowerby II 1849: 531, pl. 115, figs 213-215; Bourguignat 1853: 69; Martens 1879: 84-86, pl. 2, figs 14-16; Kobelt 1899: 2-3, pl. 211, fig. 1319 (as " N. jordanica " in figure caption).

Neritina Michonii Bourguignat 1852: 25; Bourguignat 1853: 70, pl. 2, figs 48-51.

Neritina Bellardii Mousson 1854: 52-53.

? Neritina Africana Reeve 1856: pl. 30, fig. 138a, b.

Neritina Nilotica Reeve 1856: pl. 34, fig. 157a, b; Martens 1879: 82-83, pl. 2, figs 17-19, pl. 13, figs 14-16; Kobelt 1899: 2, pl. 211, fig. 1317.

Neritina Jordani var. turris Mousson 1861: 151-152; Kobelt 1899: 3, pl. 211, fig. 1320.

Neritina Karasuna Mousson 1874: 34-35; Blanckenhorn 1897: 101-102, pl. 8, figs 6-8.

Neritina meridionalis var. Mesopotamica Mousson 1874: 35.

Neritina Euphratica Mousson 1874: 49; Kobelt 1899: 2, pl. 211, fig. 1318.

Neritina Anatolica var. Mesopotamica : Martens 1874: 33-34, pl. 5, fig. 42.

Neritina cinctella Martens 1874: 34, pl. 5, fig. 43; Martens 1879: 91, pl. 13, figs 22-24; Kobelt 1899: 4-5, pl. 211, fig. 1326.

Neritina Macrii [sic]: Martens 1879: 88-90, pl. 4, figs 11-13, pl. 13, figs 27-29 (non Neritina macri G.B. Sowerby II, 1849; partim, non pl. 13, fig. 13).

Neritina Mesopotamica : Martens 1879: 90, pl. 13, figs 20, 21; Kobelt 1899: 4, pl. 211, fig. 1325.

Neritina ( Theodoxia ) Jordani var. aberrans Dautzenberg 1894: 351.

Neritina Orontis Blanckenhorn 1897: 101, pl. 8, figs 3-5.

Theodoxia Macrii [sic]: Germain 1921: 516-518 (non Neritina macri G.B. Sowerby II, 1849).

Theodoxia jordani : Germain 1921: 511-514.

Neritina Ponsoti Pallary 1930: 286-287, fig. 1.

Theodoxus (Neritaea) jordani var. unicarinatus Picard 1934: 107-111, pl. 7, figs 1-4.

Theodoxus (Neritaea) jordani var. bicarinatus Picard 1934: 111-112, pl. 7, figs 5-8.

Neritina ( Neritaea ) Gombaulti Pallary 1939: 107, pl. 4, figs 53-56.

Neritina (Neritaea) homsensis Pallary 1939: 108, pl. 4, figs 57-61.

Neritina (Neritaea) homsensis var. major Pallary 1939: 109 (non Neritina wallisiarum var. major Récluz, 1850).

Neritina (Neritaea) homsensis var. minor Pallary 1939: 109 (nomen nudum, non Neritina minor Menke, 1828).

Neritina ( Neritaea ) Ponsoti: Pallary 1939: 109-110, pl. 4, figs 44-46.

Theodoxus (Neritaea) jordani : Tchernov 1975: 153; Schütt and Ortal 1993: 78-79, pl. 3, figs 37-41; Bandel 2001: 84-86, figs 12-20, 32-40; Amr and Abu Baker 2004: 221-222, fig. 1.

Theodoxus (Neritaea) cinctella : Schütt and Şeşen 1989a: 56-57.

Theodoxus (Neritaea) cinctellus : Schütt and Şeşen 1989b: 45-46; Yıldırım 1999: 886.

Theodoxus (Neritaea) jordani tricarinatus Schütt in Schütt and Ortal 1993: 79, pl. 3, fig. 42.

Theodoxus (Neritaea) pliocostulatus Schütt in Schütt and Ortal 1993: 79-80, pl. 3, fig. 43.

Theodoxus niloticus : Brown 1994: 45, figs 16b-c.

Theodoxus jordani : Yıldırım 1999: 886; Gürlek et al. 2019: 2993; Glöer 2019: 44, figs 30.

non Neritina mesopotamica : Mansoorian 2001: 4, figs 1-4 (= Neritina schlaeflii Mousson, 1874).

Theodoxus macrii [sic]: Amr and Abu Baker 2004: 222, fig. 2; Handal et al. 2015: 25-26, fig. 1B (non Neritina macri G.B. Sowerby II, 1849).

? Neritina cinctellus : Glöer and Pešić 2012: 13-14, fig. 2a, c.

? Neritina mesopotamica : Glöer and Pešić 2012: 14-16.

Theodoxus euphraticus : Mansoorian and Samaee 2012: 50-57 (partim, only material from Chaharmahal and Bakhtiari, Fars, Kermanshah, and Khuzestan provinces).

Neritina euphratica Glöer and Pešić 2012: 16, fig. 2d, e.

Theodoxus cf. jordani : Alhejoj and Bandel 2013: 146-147, pl. 1, figs 5-8.

Theodoxus octagonus Eichhorst 2016: 940, pl. 293, figs 1-8.

Theodoxus (Neritaea) octagonus : Mienis and Rittner 2017: 37, figs 1-3.

Theodoxus mesopotamicus : Glöer 2019: 47, fig. 34.

Theodoxus cinctellus : Gürlek et al. 2019: 2993.

Type locality.

River Jordan.

Type material.

The type material of N. jordani could unfortunately not be traced. The type material of the taxa introduced by Mousson are stored in ZMZ, including 16 syntypes of N. bellardii (coll. no. 528918) , 13 syntypes of N. euphratica (coll. no. 528916) , 20 syntypes of N. jordani var. turris (coll. no. 528930) , 5 syntypes of N. karasuna (coll. no. 528937) , and 56 syntypes of N. meridionalis var. mesopotamica (coll. no. 528912-528914). Additionally, 64 syntypes of N. cinctella are stored in ZMB (coll. no. ZMB /Moll 21732, 21735, 66639) , 2 syntypes of N. michonii are stored in MHNG ( MHNG-MOLL-111706-111707) , 2 syntypes of N. ponsoti are stored in MNHM (coll. no. MNHN-IM-2000-32754) and another one (labelled as “paratype”) is stored in RBINS (coll. no. MT 820) , and the holotype and two paratypes of T. octagonus are stored in BMSM (coll. no. BMSM 93544-93545) .

Remarks.

A number of nominal species have already been synonymised under T. jordani based on similarities in shell morphology and overlapping distribution ranges. These include N. michonii Bourguignat, 1852, N. karasuna Mousson, 1874, and N. orontis Blanckenhorn, 1897 ( Martens 1879, Alhejoj et al. 2017). Moreover, Sands et al. (2019a) suggested that T. niloticus (Reeve, 1856) from the Nile River, Egypt (which has been considered a potential synonym of N. africana Reeve, 1856; Brown 1994) is conspecific with T. jordani on the basis of molecular data-something additionally supported by Glöer (2019). Our phylogenetic analyses expand upon this; we show that T. mesopotamicus (including the synonyms N. cinctella Martens, 1874, N. anatolica var. mesopotamica Martens, 1874 ( Schütt and Şeşen 1989a, 1989b), and T. euphraticus should be considered conspecific with T. jordani (Fig. 2 ). These results support the earlier notion of Roth (1987), who suggested that T. euphraticus , T. jordani , T. mesopotamicus , and T. niloticus may be conspecific based on morphological similarities, particularly concerning the opercula (Figs 15 - 17 ).

Although no molecular data could be incorporated, we further synonymise T. octagonus Eichhorst, 2016 with T. jordani . While T. octagonus maintains a subterranean lifestyle, the species shares a number of characteristics with T. jordani besides overlapping ranges; the operculum structures of the two species are near identical with otherwise large pseudo-apophyses and both occasionally show keeling of the shell. Moreover, key characters used to distinguish T. octagonus , such as the pronounced aperture and colouration of the shells, may be mitigated when intraspecific phenotypic plasticity of both species is considered ( Heller 1979; Bandel 2001; Amr et al. 2014; Eichhorst 2016; Mienis and Rittner 2017; Figs 15 - 17 ). Likewise, the taxa N. bellardii Mousson, 1854, N. jordani var. turris Mousson, 1861, N. ponsoti Pallary, 1930, N. homsensis Pallary, 1939, T. jordani var. unicarinatus Picard, 1934, T. jordani var. bicarinatus Picard, 1934, N. gombaulti Pallary, 1939, T. jordani tricarinatus Schütt in Schütt & Ortal, 1993, and T. pliocostulatus Schütt in Schütt & Ortal, 1993 are well within the variability of T. jordani and are considered junior synonyms herein as well.

Regarding the phylogenetic placement of T. jordani , Bunje and Lindberg (2007) found T. jordani to form a sister species to T. baeticus . Sands et al. (2019a) reaffirmed this clade but found further support for a number of other species not included by Bunje and Lindberg (2007), including T. macri , which Sands et al. (2019a) found to be the closest sister species to T. jordani (also see Fig. 2 ). Theodoxus jordani and T. macri likely diverged in the early Pleistocene ( Sands et al. 2019a; Fig. 2 ).

Notes on synonymy and homonymy: Martens (1874) described two taxa from the Chabur River near Ras al-Aynin Syria, Neritina cinctella Martens, 1874 and Neritina anatolica var. mesopotamica Martens, 1874. The latter variety is a junior homonym of N. meridionalis var. mesopotamica Mousson, 1874, which was published earlier (see also the discussion in the postface of Martens 1874 and Martens 1879). Based on newly collected material, Schütt and Şeşen (1989a, 1989b) considered all three taxa ( Neritina cinctella , N. anatolica var. mesopotamica , and N. meridionalis var. mesopotamica ) to belong to the same species given multiple intermediate forms. Although they were aware of the homonymy issue and that Mousson’s name has priority, they erroneously chose T. cinctellus as the name of the species.

Distribution.

Theodoxus jordani is common throughout southern Anatolia, the Levant, Mesopotamia, and parts of the Middle East, extending to at least southern Iran, although it is probably not found eastward of the Zagros Mountains ( Roth 1987; Schütt and Şeşen 1989b; Bandel 2001; Sands et al. 2019a; Fig. 3A ). It is also present on Cyprus and in the Nile River system, Egypt ( Sands et al. 2019a). Some records of this species from Iran and Iraq (e.g. N. mesopotamica sensu Mansoorian 2001) may be misidentifications of N. schlaeflii Mousson, 1874 which inhabits the lower reaches of the Euphrates, Karun, and Tigris rivers, as well as other brackish water systems around the Persian Gulf ( Glöer and Pešić 2012).

Figures

Figure 2. Dated phylogeny of the genus Theodoxus constructed with BEAST, based on existing GenBank and newly incorporated data for COI, 16 S and ATPα (Suppl. material 1: Table S 1). Morphospecies where associations are queried are highlighted by a question mark after the species name (see the " Systematic checklist " for more information). Small green (PP ≥ 0.95) and red (PP <0.95) dots on nodes indicate the relative posterior probability support of divergence events. Node labels (1 - 32) correspond to divergence dates and HPD intervals in millions of years ago (Mya) for selected nodes (see Suppl. material 1: Table S 3). Dashed dark blue and light blue lines represent the minimum interspecific and maximum intraspecific variation determined by Sands et al. (2019 a) to aid Theodoxus spp. delimitation (see see Methods, Phylogenetics and species delimitation and that study for more information on the delimitation methods).

Figure 3. Occurrence map for Theodoxus spp. in Asia. All points conform to specimens used in the phylogenetic analyses (Suppl. material 1: Table S 1), except for T. gloeri for which no molecular data are available and only the type and paratype localities are indicated. Species are partitioned across four identical maps (A - D) to limit overlap of points as far as possible. Barring T. gloeri, closer related species are grouped together (Fig. 2).

Figure 15. Theodoxus jordani (G. B. Sowerby I, 1836). A - D. Specimen from the Avakas Gorge, Peyia, Cyprus (UGSB 18321) incorporated into the phylogeny (Fig. 2); E - H. Specimen collected in the Ceyhan River, Eski Misis, Adana, Turkey (UGSB 20777); I - L. Specimen from the Orontes River, Antakya, Hatay, Turkey (UGSB 24175) used in the phylogeny (Fig. 2); M - O. Specimen (T. euphraticus - morphotype) from the Seyed Hosein Park spring, near the Bishapur, Fars, Iran (UGSB 22233); P - R. Topotype of N. jordani from the River Jordan, Israel (UGSB 24177) incorporated into the phylogeny (Fig. 2); S, T. Specimen (T. euphraticus - morphotype) from the Karun River, Ahvaz, Iran (UGSB 21681); U. Specimen (T. niloticus - morphotype) collected in the Nile River, Egypt (UGSB 24178) used in the phylogeny (Fig. 2); V. Specimen (T. euphraticus - morphotype) from the Karun River, Ahvaz, Iran (UGSB 21682). Scale bars: 1 mm.

Figure 16. Theodoxus jordani (G. B. Sowerby I, 1836). A, B. Syntype of N. euphratica from the Euphrates River at Samawah, Iraq (ZMZ 528916); C - E. Syntype of N. michonii from Syria (MHNG-MOLL- 111706); F - H. Syntype of N. karasuna collected from the Karasu River, south-eastern Turkey (ZMZ 528937); I, J; K, L. Two syntypes of N. ponsoti from Lake Muzayrīb, Syria (MNHN-IM- 2000 - 32754); M. Syntype (labelled as paratype) of N. ponsoti from Lake Muzayrīb (MT 820, RBINS); N. Syntype of N. jordani var. turris collected in the Sea of Galilee (ZMZ 528930); O, P. Syntype of N. bellardii from the Litani River, Beqaa valley, Lebanon (ZMZ 528918). Scale bars: 1 mm.

Figure 17. Theodoxus jordani (G. B. Sowerby I, 1836). A - C. Syntype of N. meridionalis var. mesopotamica from near Diyarbakir, Turkey (ZMZ 528914); D, E. Specimen (T. mesopotamicus - morphotype) collected in Sanliurfa, Turkey (UGSB 23426) and used in the phylogeny (Fig. 2); F - H; K - M. Two syntypes of N. cinctella collected at the source of River Chabur near Ras al-Ayn, Syria (ZMB / Moll 21732); I, J. Topotype of N. cinctella from the same locality (UGSB 18762). Scale bars: 1 mm.