Plagigeyeria mostarensis , Kuscer 1933
Creators: name: Grego, Jozef
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Littorinimorpha
Hydrobiidae
Plagigeyeria
Plagigeyeria mostarensis

description: Plagigeyeria mostarensis Kuščer, 1933.
Figs 7 A–E, 8D
Plagiogeyeria (sic) mostarensis Kuščer, 1933: 62, pl. 1 fig. 3.
Plagigeyeria mostarensis – Jaeckel, Klemm & Meise 1957: 174. — Jaeckel 1967: 92. — Schütt 1972: 119, pl. 6. fig. 3. — Willmann & Pieper 1978: 126. – Bole & Velkovrh 1986: 202, fig. 37. — Bodon, Manganelli & Giusti 1996: 33, fig. 13. — Bank 2013: Fauna Europaea v. 2.6.
Diagnosis
Shell elongate-conical with distinct regular ribbing, deep suture and very widely expanded, trumpetlike aperture stepwise pronounced at the basal view. The lateral and columellar profiles of the aperture are characteristically sinuated. Umbilicus slit-like. Nepionic whorl ribbed, only slight spiral ribs, and protoconch surface covered by irregular spiral ribs with inter-rib granulations, nucleus weakly malleated.
Distribution
Known from the springs of rivers Buna (36 m a.s.l.) and Bunica (55 m a.s.l.) southwest of Mostar. Springs are most likely draining water through karst conduits from Trusinsko Polje (866 m a.s.l.), Nevesinjsko Polje (817 m a.s.l.) and Rotimlja Polje (422 m a.s.l.).
Remarks
Kuščer (1933) described P. mostarensis with the type locality as the vrelo “Buna” (36 m a.s.l.). However, the Buna spring hosts a different morphotype, while the typical morphotype can be found in the nearby Vrelo “Bunica” (55 m a.s.l.). He also reported the same type locality for P. ovalis, which was not confirmed in Vrelo “Buna” but only in the Vrelo “Bunica” (see remark on P. ovalis). Both species were also figured by Schütt as from the Vrelo “Bunica”. We suppose that Kuščer's specimens were actually collected from Vrelo “Bunica”, which most likely represents the true type locality of both taxa. It is probable that both springs were treated as the one well-known Vrelo “Buna” on the original collection label. The shells of P. mostarensis known from the Vrelo “Buna” (Buna morphotype) (Fig. 5 D–E) differ from the typical form figured by Kuščer and known only from the Vrelo “Bunica” (Bunica morphotype) (Fig. 5 A–C) by their more pagoda shape of shell with more angled whorls with different suture and different shape of marginal sinuation. The Buna morphotype of P. mostarensis is predominantly found in the deposits of the large main stream of Buna River. In all four small side streams at the left bank rising 300–600 m downstream from the main Buna resurgence the empty shells of P. pseudocostellina sp. nov. (Fig. 5 G–H) can be found. These are separated by a straight, not sinuated, rounded aperture very similar to Paladilhiopsis (Costellina) turrita (Kuščer, 1933) (known only from the small spring Izvor in Jadro Valley near Split, Croatia). The taxonomical importance of the Buna morphotype is still under investigation and for the time being, it is listed under P. mostarensis. Plagigeyeria reischuetzorum described herein from Vrelo “Vrijeka” in Dabarsko Polje (472 m a.s.l.) in the upper Bregava Basin, which is likely draining the karstwater from Slato Polje (1012 m a.s.l.) and Lukavačko Polje (895 m a.s.l.), is morphologically the closest relative of P. mostarensis. The karst conduits of Bregava Basin indicate at least an occasional divergence of its waters into the Vrelo “Bunica” (55 m a.s.l.), thus their close relation is not surprising.
description: Published as part of 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, pp. 1-56 in European Journal of Taxonomy 691 on page 16, DOI: 10.5852/ejt.2020.691, http://zenodo.org/record/3961840