Plagigeyeria erossi Grego 2020, sp. nov.
Creators: name: Grego, Jozef
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Littorinimorpha
Hydrobiidae
Plagigeyeria
Plagigeyeria erossi

description: Plagigeyeria erossi sp. nov.
urn:lsid:zoobank.org:act: 405BAA2B-296D-4B18-9D62-343C35A6963E
Figs 9 A–C, 10A
Type material
Holotype
BOSNIA AND HERCEGOVINA • 1 shell; Bosnian Federation, Herzegovina-Neretva Canton, Donja Jablanica, Komadinovo Vrelo, 2 km SW of, and under the road from Mostar to Jablanica, side outlet of main spring at left bank of Neretva (Fig. 2D); 43.617298° N, 17.741081° E; 180 m a.s.l.; 30 Jul. 2016; J. Grego and Z. P. Erőss leg.; HNHM-MOLL-104166.
Paratypes
BOSNIA AND HERCEGOVINA • 3 shells; same data as for holotype; HNHM-MOLL-104167/1, coll. Grego /1, coll. Erőss /1. • 1 shell; same locality as holotype; 29 Mar. 2018; Jozef Grego leg; coll. Grego /1.
Dimensions
Holotype: H 2.10 mm; W 1.13 mm; BH 1.25 mm; BW 0.90 mm; AH 0.87 mm; AW 0.72 mm.
Paratypes:
H 2.01 mm; W 1.28 mm; BH 1.12 mm; BW 0.93 mm; AH 0.88 mm; AW 0.77 mm.
H 1.79 mm; W 1.09 mm; BH 1.12 mm; BW 0.88 mm; AH 0.79 mm; AW 0.70 mm.
Etymology
Named after my friend Zoltán Péter Erőss, president of the Hungarian Malacological Society, Budapest, who participated in the field trip and brought my attention to the locality of the new species.
Description
Solid, narrow, conical shell, 2.1 mm in height, with blunt apex, milky-white colour and four convex whorls separated by a deep suture. Shell surface very finely axially ribbed especially at the late teleoconch and ribs cross-sected by irregular wavy faint spiral structures. Nepionic whorl covered by 18 close-set spiral ribs, continuing apically into fine irregular granulose cord-like structure at protoconch and smoothly malleate nucleus. Umbilicus open, partly obscured by the strongly reflexed columellar margin. Larger expanding reflexed aperture oval, attached to the body whorl in its upper columellar part. Peristome blunt, reflexed along aperture outline. Outer lip lateral profile characteristically sinuous adapically as well as having a characteristic sinuation which is present at the columellar lip. Expanded aperture stepwise protruded against body whorl at frontal view.
Differentiating features
Compared with the geographically closest Plagigeyeria mostarensis Kuščer, 1933 (Hercegovina, Blagaj) (Fig. 7 A–E), the new species differs by its smaller cylindrical and less conical shell shape, blunter rounded apex and less prominent protoconch, more open umbilicus, as well as by a proportionally smaller and more oval aperture. The new species has a characteristic sinuation at outer and inner lips and a less prominent aperture within the shell peripheral outline. The shell morphology of the new species is closely related to Plagigeyeria plagiostoma (A. J. Wagner, 1914) from the spring of the river Bosna near Ilidža, which differs by its more slender shell, cylindrical shape, more open umbilicus, different sculpture of the protoconch, proportionally smaller aperture and a weaker marginal sinuation. Shell morphometry comparison with the related species is presented in the Table 2.
Habitat
The type locality is a large karst spring rising at the right bank of Neretva River among large stone blocks under highway (Sarajevo-Mostar) and draining the limestone massif of Mt Prenj (2115 m a.s.l.) in Čvrsnica Massif (highest peak Pločno, 2228 m a.s.l.). Due to a strong current in the spring zone, there was not enough fine sediment in the main spring zone, but empty shells had been found in two smaller side springs at the left side of the main outlet. This species most likely inhabits an undiscovered karst conduit upstream the spring inside the Čvrsnica Massif.
Distribution
Only known from the type locality.
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 pages 25-26, DOI: 10.5852/ejt.2020.691, http://zenodo.org/record/3961840