Plagigeyeria erossi, 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 : 25-26

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.

Figures

Fig. 9 (next page). A. Plagigeyeria erossi sp. nov., Mostar district, Komadinovo Vrelo at right bank of Neretva below Donja Jablanica, holotype (HNHM-MOLL- 104166). B–C. P. erossi sp. nov., type locality, paratypes (JG F0518, JG F1122). D. P. lewarnei sp. nov., Trebinje district, Gorica, cave Vruljak, holotype (HNHM-MOLL-104176). E. P. listicaensis sp. nov., Široki Brijeg, Bilo Vrelo (Lištica 2), holotype (HNHM-MOLL-104168). F. P. listicaensis sp. nov., type locality, paratype (JG F1250). G–H. P. reischuetzorum sp. nov., Dabarsko Polje, Vrelo Vrijeka. G. Paratype (HNHM-MOLL-104165). H. Paratype (JG F1173). I. P. reischuetzorum sp. nov., type locality, holotype (NHMW 111678). J. P. reischuetzorum sp. nov., type locality, paratype (JG F1158). K–L. Travunijana gloeri sp. nov., Dabarsko Polje, Vrelo Vrijeka. K. Holotype (HNHM-MOLL-104418). L. Paratype (JG F1340).

Fig. 2. Photos of studied localities in Hercegovina. A. Konjic. Ljuta spring (LT of Plagigeyeria ljutaensis sp. nov.). B. Blagaj, spring Buna (P. mostarensis var.). C. Konjic, spring at left bank of Ljuta Rivulet (LT of P. konjicensis sp. nov.). D. Donja Jablanica, Komadinovo Vrelo (LT of P. erossi sp. nov.). E. Vučija, Sušicka Jama (P. cf. lewarnei sp. nov.). F. Trebinje, Gorica, spring Vruljak 1 (P. robusta and P. lewarnei sp. nov.). Photos: Jozef Grego, Dorottya Angyal and Mário Olšavský.

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).