Plagigeyeria mostarensis Kuščer, 1933

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 : 16

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.

Figures

Fig. 7 (next page). A. Plagigeyeria mostarensis, Kuščer 1933, holotype, from Kuščer 1933, assigned to Izvor Buna in Blagaj but rather represents the form from near spring Bunica in Hodbina. B. P. mostarensis, hypotype of Schütt, 1970, from spring Bunica (SMF 221236). C. P. mostarensis, likely topotype from spring Bunica (JG F1146). D–E. P. mostarensis var., from spring of Buna assigned as type locality (JG F0536). Fa–Fb. Paladilhiopsis (Costellina) turrita (Kuščer, 1933) paratype and holotype from Kuščer 1933, spring Izvor in valley of river Jadro near Split. G. P. pseudocostellina sp. nov., left bank side spring of river Buna 400 m from main spring (holotype HNHM-MOLL-104164). H. P. pseudocostellina sp. nov., left bank side spring of river Buna 200 m from main spring (paratype JG F1140). I. Travunijana ovalis (Kuščer, 1933), holotype from Kuščer, assigned to Izvor Buna in Blagaj but not found in assigned locality, only in spring Bunica in Hodbina. J–K. T. ovalis (Kuščer, 1933), spring Bunica near Hodbina (JG F1145). L. T. robusta (Schütt, 1959), Trebinje district, Tučevac spring at right bank of Trebišnjica River (JG F1163). M. T. robusta, Trebinje district, Gorica, cave Vruljak 1 (JG F0831). N. T. robusta asculpta (Schütt, 1972), spring Ombla (Dubrovačka Rijeka) at Komolac near Dubrovnik (JG F1080).

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).