Stygobium hercegnoviensis Grego and Glöer, 2019

Grego, Jozef, Glöer, Peter, Falniowski, Andrzej, Hofman, Sebastian & Osikowski, Artur, 2019, New subterranean freshwater gastropod species from Montenegro (Mollusca, Gastropoda, Moitessieriidae, and Hydrobiidae), Ecologica Montenegrina 20 (2019), pp. 71-90 : 82-83

Stygobium hercegnoviensis Grego and Glöer n. sp.

( Figs. 7–9 )

Type locality

Montenegro: Herceg Novi , Savina , below Savina Monastery under Braće Grakalić street at Melinje Hospital, behind the neonatal pavilion, 42.451656°N; 18.555225°E, 16 m a.s.l. ( Fig. 2A ) .

Type material

Holotype: Type locality, J. Grego leg., 26.07.201 6 ( HNHM 103037 ) . Paratypes: same data ( HMUK 20180026 /2, SMF 349441 /2, CNHM 11479/2, NMBE 554116/2, coll. Glöer /1, coll. Grego /22) ; same data, Z. P. Erőss and Z. Fehér leg. , 16.07.201 7 ( HNHM 103038 /73, NHMW 111665 /2, Grego/6) ; same data, Z. P. Erőss and Z. Fehér leg. , 16.07.201 8 coll HNHM 115 , ZPE/55 coll. Grego / 55 Montenegro: Herceg Novi , right bank spring of Nemila rivulet, on turn of Spasića i Masare street, 42.456214°N; 18.538386°E, ( Fig.2E ), Jozef Grego leg. , 26.07.201 6 (coll Grego/1); same locality Z. P. Erőss and Z. Fehér leg., 16.07.2017 (coll. Grego /4); 714 HNHM /4 ; Montenegro: Herceg Novi : Sušćepan, Izvor Vostanj above the village, 42.468768°N; 18.513022°E, ( Fig.2C ), Jozef Grego leg. , 28.7.201 6 (coll. Grego /34); Montenegro: Herceg Novi , Trebesinj, springs above the village behind Crkva St. Tome, 42.472 886°N, 18.524117°E, ( Fig.2B ), Jozef Grego leg. , 28.7.201 6 (coll. Grego /20); Montenegro: Herceg Novi , Zelenika - Kuti, side rivulet of Opaĉica, spring behind last house, 42.462747°N, 18.587347°E, J. Grego and Z. P. Erőss leg. , 25.07.201 6 (coll. Grego/6).

Measurements

Holotype: H 1.65 mm; W 0.68 mm; BH 0.87 mm; BW 0.61 mm; AH 0.45 mm; AW 0.44 mm.

Etymology

Named after the type locality situated inside Herceg Novi town at north shore of Kotor Bay, Montenegro .

Description

Fragile milky yellowish, silky, translucent shell with 4½ convex whorls with a deep suture and a blunt apex. Shell surface smooth with very weak axial growth lines. Shell small (1.65mm), elongate, subconical, slightly tapering towards the blunt apex. Umbilicus tiny, slit like. Aperture ear-shaped, proportionally smaller than body whorl, from which separated by a weak furrow. Peristome margin sharp and not reflexed reflected. Outer lip straight in lateral view and slightly scooped backward at its anterior end. In frontal profile lip aligned with the tapering shell outline.

Differentiating features

According to molecular data (only H3), the new genus forms a distinct Hydrobiid clade among the Agrafia Szarowska & Falniowski, 2011 , Hauffenia Pollonera, 1898 , Belgraniella Wagner, 1928 and Montenegrospeum Pešić & Glöer, 2013 group, with a p- distance 0.039 to 0.062.

The small elongate shell of the new genus can be compared with two Albanian species provisionally treated in the family Moitessieriidae : Paladilhiopsis szekeresi Grego et al., 2017 ( Albania, Tamarë) and Paladilhiopsis prekalenis Grego et al., 2017 ( Albania, Prekal). From both it differs by its more slender elongated conical shell, less blunt apex, and smaller aperture, which is situated expanded more on the columella side (Tab. 1). The availability of molecular data from the above two Paladilhiopsis species could possibly confirm their affiliation with the new genus Stygobium .

Habitat

The type locality is a small spring captured in a cistern with one central outlet and one leak near the neonatal building of Meljine Hospital. Few live specimens and empty shells were found in sandy sediment of the drainage channel collecting the leaked water. All the other known localities along NW coast of Kotor Bay have a similar stony cisterns with roughly-carved stone outlets collecting spring water, and the specimens were found in sediments near these outlets. Most likely, the species inhabits the underground water channels and stony water reservoirs, and only the occasionally washed-out specimens are trapped in sand beyond the water outlet.

Distribution

Aside from the type locality on the grounds of Meljine Hospital, the species is known in the greater vicinity of Herceg Novi on the N shore of Kotor Bay: at Sušćepan, Trebesinj, Zelenika- Kuti and two springs near the right bank of Nemila rivulet Rivulet at 18 - 320 m altitude. In the locality near Zelenika the species is found with Paladilhiopsis cattaroensis n. sp., and at Nemila with Saxurinator matejkoi n. sp. while at the type locality its syntopic with Plagigeyeria feheri n. sp.

Figures

Figure 2. Photographs of studied localities: A. Montenegro: Herceg Novi, Meljine Hospital (Stygobium hercegnoviensis n. sp., Plagigeyeria feheri n. sp); B. Montenegro: Herceg Novi, Trebesinj (S. hercegnoviensis n. sp.); C. Montenegro: Herecg Novi, Sušćepan, Izvor Vostanj (S. hercegnoviensis n. sp.); D. Montenegro: Kotor Bay with Risan, arrow. Velika Špilja (Plagigeyeria pageti forma minor, Schütt, 1961); E. Montenegro, Herceg Novi, Nemila (S. hercegnoviensis n. sp., Paladilhiopsis matejkoi n. sp.); F. Montenegro: Izvor Vitoja (Bosnidilhia vitojaensis n. sp.). (photo’s: Jozef Grego and Maroš Grego).

Figures 3-8. Discussed species of the genus Paladilhiopsis, Bosnidilhia, and Stygobium: 3–4 Paladilhiopsis cattaroensis n. sp. (Holotype HNHM 103039); 5 Bosnidilhia vreloana (Holotype ZMH 79663); 6 Bosnidilhia vitojaensis n. sp. (Holotype HNHM 103041); 7-8 Stygobium hercegnoviensis n. sp. (Holotype HNHM 103037) (photo´s: Peter Glöer, Jozef Grego)

Fig. 9. The penis of Paladilhiopsis (Lanzaia) matejkoi n. sp.