Theodoxus macri (G.B. Sowerby II, 1849)

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 macri (G.B. Sowerby II, 1849) Figure 18A-H

Neritina Macri G.B. Sowerby II 1849: 531, pl. 116, fig. 222.

Neritina Macrii [sic]: Martens 1879: 88-90, pl. 13, fig. 13 (partim, non pl. 4, figs 11-13, pl. 13, figs 27-29); Blanckenhorn 1889: 81 (synonymy tentative); Kobelt 1899: 5, pl. 212, figs 1327, 1328 (partim, excluding synonyms).

non Theodoxia Macrii [sic]: Germain 1921: 516-518.

non Theodoxus macrii [sic]: Amr and Abu Baker 2004: 222, fig. 2; Handal et al. 2015: 25-26, fig. 1B.

? Theodoxus macrii [sic]: Glöer 2019: 46, fig. 32.

Type locality.

Asia Minor (= Anatolia).

Type material.

According to Dance (1966), most material described by G.B. Sowerby II is deposited in BMNH, and parts also in the Tomlin Collection of NMW. Unfortunately, the types could not been located in either of these two institutions (A. Salvador, H. Wood pers. comm. 07/2018).

Remarks.

The identity of this species is doubtful at the moment. G.B. Sowerby II (1849) based it on a black periostracum, oval shell, and a grey, more inclined columellar plate. The short description and sole figure, as well as the imprecise locality information ("Asia Minor") and the apparent lack of type material, render an attribution of newly collected specimens to that species uncertain. Sands et al.'s (2019a) material from eastern Cilicia and south-east Anatolia fit well in terms of shell shape and periostracum colouration, and we tentatively consider them to belong to T. macri (Fig. 18 ). The previous perception of T. macri was a different one though. In the literature of the late 19th century, it has been commonly considered a more widely distributed Middle Eastern species, with the junior synonyms N. karasuna and N. michonii ( Martens 1879, Westerlund 1886, Kobelt 1899). More recently, Dagan (1971), Tchernov (1975), and Bandel (2001) considered T. macri a junior synonym of T. jordani , but based only on material from Israel and Jordan. Molecular analyses suggest that Theodoxus from Jordan, Israel, and Palestine belong to a single species, T. jordani , which is distinct from all other species ( Sands et al. 2019a; Fig. 2 ). Although the true identity of T. macri remains dubious at the moment, these results indicate that T. macri does not occur outside of Cilicia and south-eastern Anatolia. Probably all previous records of T. macri from the Middle East (e.g. Najim 1959; Elkarmi and Ismail 2006; Handal et al. 2015) refer to T. jordani . If this is corroborated, T. macri likely diverged from a common ancestor with T. jordani in the early Pleistocene ( Sands et al. 2019a; Fig. 2 ).

Note on authority: G.B. Sowerby II (1849) attributed the name to Récluz based on a manuscript name, but Sowerby remains the sole author of this species.

Distribution.

The distribution range of T. macri cannot be fully elucidated at present (see Remarks). The material studied by Sands et al. (2019a) derives primarily from the drainage systems in eastern Cilicia and nearby drainages in south-east Anatolia (Fig. 3A ).

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 18. Theodoxus macri (G. B. Sowerby II, 1849). A - D. Specimen collected close to Harbiye Falls, Harbiye, Antakya, Turkey (UGSB 24179); E - H. Specimen from Lake Yenisehir, Reyhanli, Turkey (UGSB 24180); I, J. Specimen from Lake Balik, Adalar, Turkey (UGSB 24181). All specimens (A-J) were used in the phylogeny (Fig. 2). Scale bars: 1 mm.