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

description: Plagigeyeria olsavskyi sp. nov.
urn:lsid:zoobank.org:act: 24E627A4-A78B-4447-BB44-B34BB9D0F943
Figs 5 F–I, 10C–D
Type material
Holotype
BOSNIA AND HERCEGOVINA • 1 shell; Herzegovina-Neretva Canton, Studenci, Vrelo “Kajtazovina” in Studeničko Polje (Fig. 3D); 43.169696° N, 17.628004° E; 53 m a.s.l.; 1 Apr. 2018; J. Grego, D. Angyal, G. Jakab, M. Olšavský leg; HNHM-MOLL-104178.
Paratypes
BOSNIA AND HERCEGOVINA • 3 shells; same data; coll. Grego/3 • 45; same locality as holotype; 22 Apr. 2019; J. Grego, M. Olšavský, G. Jakab and M. Kováčiková leg.; HNHM-MOLL-105100/1, coll. Grego /44 • 41 shells; West Herzegovina Canton, Ljubuški district, Donji Proboj, Vrelo “Mali Prokop” 400 m north of road M6; 43.223905° N, 17.514440° E; 98 m a.s.l. (Fig. 4C); 2 Apr. 2018; J. Grego, D. Angyal, G. Jakab and M. Olšavský leg.; SBMNH 626260 /7, coll. Grego /32, coll. Reischütz /1.
Dimensions
Holotype: H 2.01 mm; W 1.52 mm; BH 1.22 mm; BW 1.07 mm; AH 0.9 mm; AW 0.93 mm.
Paratypes:
H 2.00 mm; W 1.32 mm; BH 1.25 mm; BW 0.99 mm; AH 0.94 mm; AW 0.79 mm.
H 2.03 mm; W 1.42 mm; BH 1.25 mm; BW 1.01 mm; AH 0.85 mm; AW 1.07 mm.
H 1.87 mm; W 1.34 mm; BH 1.19 mm; BW 0.96 mm; AH 0.86 mm; AW 0.69 mm.
Etymology
Named after my friend Mário Olšavský, speleologist and geologist from Banská Bystrica, Slovakia, who actively helped with the sampling of springs in our field trips.
Description
Elongate-pyramidal 2 mm-high shell with flat blunt apex and four convex whorls separated by a deep suture; milky-white colour and distinctly open umbilicus. Shell surface covered by fine regular axial ribs at last two teleoconch whorls, nepionic whorl with cancellate surface and dominating axial ribs, embryonal whorls covered by irregular faint spiral rib-like structure with raised malleate structures at the interspaces. Rounded or slightly oval aperture with slightly outward reflexed margins. Sharp peristome slightly expanded along aperture outline. Outer lip lateral profile forward protruding and very weakly sinuous adapically and straight to very weakly sinuated at the columellar lip. The aperture is conspicuously stepwise protruded against the shell outline at the basal view.
Differentiating features
The shell morphology of the new species closely resembles P. inflata (A. J. Wagner, 1928), differing by its smaller and less conical shell, less open umbilicus, more blunt apex and a more rounded shape of the aperture. From P. plagiostoma it differs by having a more robust shell shape with a more prominent body whorl and broader umbilicus. Shell morphometry comparison with the related species is presented in the Table 2.
Habitat
The type lot was found in the sediments of two springs at a left tributary of the Tihaljina (Trebižat) River:
1. Vrelo “Kajtazovina” (53 m a.s.l.) in Studeničko Polje (LT): a large karst spring with a small cave and ruins of a water mill with a bridge at its mouth. Spring likely draining the water from Čitlučko Polje (217 m a.s.l.).
2. Vrelo “ Mali Prokop” (98 m a.s.l): A small spring rising from a crack in the limestone massif just beside the road to the northernmost houses of Donji Proboj Village. The small amount of sandy sediment is accumulated at the bottom of the shallow spring basin. The spring outlet looks to be almost constant during the year and not influenced by the spring maxima in the other neighbouring springs. It is likely draining the water from Rašanjsko Polje (344 m a.s.l.).
Distribution
Only known from the type locality and the nearby Vrelo “ Mali Prokop” in Donji Proboj in the left tributary of the Tihaljina (Trebižat) River.
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 26-29, DOI: 10.5852/ejt.2020.691, http://zenodo.org/record/3961840