Plagigeyeria inflata (A. J. Wagner, 1928 )

Grego, Jozef, 2020, Revision of the stygobiont gastropod genera Plagigeyeria Tomlin, 1930 and Travunijana Grego & Glöer, 2019 (Mollusca; Gastropoda; Moitessieriidae and Hydrobiidae) in Hercegovina and adjacent regions, European Journal of Taxonomy 691, pp. 1-56 : 12

Plagigeyeria inflata (A. J. Wagner, 1928)

Figs 5C , 6D

Geyeria plagiostoma inflata A. J. Wagner, 1928: 285 , pl. 13. figs 68–69, 72.

Plagigeyeria plagiostoma f. inflata – Schütt 1972: 119, fig. 2.

Plagigeyeria plagiostoma – Bank 2013: Fauna Europaea v. 2.6 — Bank & Neubert 2017: 25.

Diagnosis

The species can be separated from Plagigeyeria plagiostoma by its larger shell (2.5 mm high against 1.9 mm) with a more robust and more conical shell shape with more open umbilicus and less blunt apex, by larger, more expanded aperture and by coarser ribs with different cancellate surface of the nepionic whorl.

Distribution

Only known from the type locality in Vrelo Bosne (581 m a.s.l.) near Ilidža, South of Sarajevo.

Remarks

Plagigeyeria inflata (A. J. Wagner, 1928) was described from the same spring where the empty shells of P. plagiostoma had been present and, supposing their subspecific status and identical locality, the two species were synonymized by Schütt (1972) and then again in the Fauna Europaea ( Bank 2013). Nevertheless, I have to note their conchological distinctness without intermediates, and that both species were found in the same locality only as empty shells washed together within the recent thanatocoenoses of the spring zone. We have no idea about the underground aquifer range and about its mutually separated cave branches. It is very common in the morphology of many spring caves, that the large isolated, hydrologically active cave passages converge their flow just upstream of the spring outlet. Thus we cannot exclude the presence of two separated species or populations existing within one cave system without being sympatric. The recent thanatocoenoses do not represent their true habitat. Both species are very well differentiated by their shell shape and size ( Wagner 1928; Schütt 1972) without any intermediate and I prefer to treat them as two independent species.

Figures

Fig. 5 (next page). A. Plagigeyeria plagiostoma (A. J. Wagner, 1914), from Vrelo Bosne in Ilidža, (topotype JG F1116). B. Travunijana vruljakensis Grego & Glöer, 2019, Gorica near Trebinje, spring Studenac (holotype HNHM-MOLL-104416). C. P. inflata (A. J. Wagner, 1928), from Vrelo Bosne in Ilidža (topotype JG F1117). D. P. ljutaensis sp. nov., Konjic district, spring of River Ljuta (holotype HNHM-MOLL-104180). E. P. konjicensis sp. nov., small spring at left bank of Ljuta River, 600 m downstream of the main spring (holotype HNHM-MOLL-104174); F–G. P. olsavskyi sp. nov., Studenci, spring Kajtazovina F. Holotype (HNHM-MOLL-104178). G. Paratype (JG F1192). H–I. P. olsavskyi sp. nov., Ljubuški district, Donji Proložac, spring Mali Prokop (JG F1209).

Fig. 6. A. Plagigeyeria ljutaensissp. nov., Konjic,Vrelo Ljuta, paratype (SBMNH 626401).B. P.konjicensis sp. nov., Konjic, left side spring of Ljuta River, paratype (SBMNH 626249). C. P. plagiostoma (A. J. Wagner, 1914), Sarajevo, Ilidža, Vrelo Bosne, (SBMNH 632718). D. P. inflata (A. J. Wagner, 1928), Sarajevo, Ilidža, Vrelo Bosne (SBMNH 33032). Scale bars = 1 mm (SEM SBMNH Vanessa Delnavaz).