Plagigeyeria jakabi, Grego, 2020

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 : 32-33

Plagigeyeria jakabi sp. nov.

urn:lsid:zoobank.org:act:8FFFE2C7-2DB1-4F0E-9FAD-D8027A4DD709

Fig. 12 A–B

Type material

Holotype

BOSNIA AND HERCEGOVINA • 1 shell; Herzegovina-Neretva Canton , Studenci-Guljevina, Vrilo “Guljevina” ( Fig. 4A ); 43.181472° N, 17.602929° E; 77 m a.s.l.; 2 Apr. 2018; J. Grego, D. Angyal, G. Jakab and M. Olšavský leg.; HNHM-MOLL-104172.

Paratype

BOSNIA AND HERCEGOVINA • 1 shell; same data as for holotype; coll. Grego /1 .

Dimensions

Holotype: H 2.52 mm; W 1.58 mm; BH 1.45 mm; BW 1.14 mm; AH 1.17 mm; AW 1.00 mm.

Paratype: H 2.45 mm; W 1.40 mm; BH 1.45 mm; BW 1.14 mm; AH 1.13 mm; AW 1.07 mm.

Etymology

Named after my friend Gabriel Jakab, a speleologist from Plešivec, Slovakia, who supported all our Balkan field trips and helped to explore the type locality of the new species.

Description

Solid elongate-conical 2.5 mm-high shell with blunt rounded apex, milky-yellowish colour and 4.5 convex inflated whorls separated by a deeply cut suture. Shell surface regularly axially ribbed with faintly granulose interstices. Nepionic whorl almost smooth with faint spiral rib-like structures. Umbilicus narrow, slit-like, partly obscured by the reflexed columellar marginal fold. The larger expanding reflexed aperture is tear-shaped with a sinulus-like extension at its upper-right end. Peristome blunt and trumpetlike reflexed along aperture outline, especially at upper marginal part. Outer lip lateral profile very weakly sinuous and characteristic sinuation present at columellar lip profile. Expanded aperture stepwise and conspicuously protruded against body whorl at basal view.

Differentiating features

P. jakabi sp. nov. differs from all related species like P. angyaldorkae sp. nov. by a typically tear-shaped aperture with a sharply conspicuous indication of a posterior channel and an oval rounded bottom part of the aperture and, by a less sinuated labral margin and by a more prominent body whorl. Shell morphometry comparison with the related species is presented in the Table 3 .

Habitat

The shells of the new species were washed out from subterranean aquifers through a large karst spring “Vrilo” in Guljevina (77 m a.s.l.). The spring rising under the thick vertical Neogene limestone cliff with a smaller cave left from the outlet and water mill ruins downstream. It is likely draining the water from Mokro Polje (230 m a.s.l.).

Distribution

Only known from the type locality.

Figures

Fig. 12. A–B. Plagigeyeria jakabi sp. nov., Studenci, spring Guljevina A. Holotype (HNHM- MOLL-104172). B. Paratype (JG F1204). C–D. P. vriosticaensis sp. nov., Vitina, Vrelo Vrioštica C. Holotype (HNHM-MOLL-104182). D. Paratype (JG F1214). E. P. angyaldorkae sp. nov., Vrelo Jakšenica (holotype HNHM-MOLL- 104163). F. P. ozimeci sp. nov., Vitina, Vrelo Vrioštica, holotype (HNHM-MOLL-104173). G–K. P. ozimeci sp. nov., Vitina, Vrelo Vrioštica, paratypes (JG F1215).

Fig. 4. Photos of studied localities in Hercegovina. A. Studenci, Vrilo Guljevina (LT of Plagigeyeria jakabi sp. nov.). B. Široki Brijeg, Bijelo Vrelo – Lištica 2 (LT of P. listicaensis sp. nov.) C. Donji Prolog, spring Mali Prokop (P. olsavskyi sp. nov.). Photos: Jozef Grego, Dorottya Angyal and Mário Olšavský.