Spelaeodiscus virpazarioides Pall-Gergely & Feher, 2018

Pall-Gergely, Barna, Deli, Tamas, Eross, Zoltan Peter, Reischuetz, Peter L., Reischuetz, Alexander & Feher, Zoltan, 2018, Revision of the subterranean genus Spelaeodiscus Brusina, 1886 (Gastropoda, Pulmonata, Spelaeodiscidae), ZooKeys 769, pp. 13-48 : 13

Spelaeodiscus virpazarioides Pall-Gergely & Feher sp. n. Figure 14M-R

Type material.

Albania, Malësia district, a mountain pass 2 km N of Rraps-Starjë, 700 m a.s.l., 42°24.888'N, 19°30.240'E, leg. Erőss, Fehér, Szekeres, Grego, 27.06.2016, HNHM 103417 (holotype, SW = 3.45 mm, SH = 2.0 mm), HNHM 102765/4+1subadult+3fr (paratypes), NHMW 111672/3+2subadult+2fr; JG/3+2subadult+3fr (paratypes); same locality, leg. A. Reischütz, N. Reischütz & P. Reischütz, Apr. 2006, REI/1 juvenile paratype.

Type locality.

Albania, Malësia district, a mountain pass 2 km N of Rraps-Starjë, 700 m a.s.l., 42°24.888'N, 19°30.240'E.

Diagnosis.

A medium sized to large species with elevated spire, strong, very widely spaced ribs, fine spiral lines consisting of series of minute tubercles, hammered protoconch, weak basal thickening, weak parietal tooth, and a thickened parietal callus.

Description.

Spire elevated; protoconch consists of ca. 1.25-1.75 whorls, roughly sculptured, “hammered”; teleoconch with very strong, equidistant, widely spaced ribs (40-70 on the body whorl; addition to the radial ribs very fine, dense spiral striation is visible on the entire teleoconch, consisting of minute tubercles; entire shell with 4-4.75 whorls; aperture subcircular/triangular; basal part with two low swellings (similar to those of S. albanicus albanicus ), parietal wall with a weak tooth; parietal callus thickened, blunt; umbilicus funnel-shaped, relatively narrow.

Measurements. SW: 3.3-3.6 mm (median = 3.5 mm), SH: 1.95-2.25 mm (median = 2.1 mm), AW: 1.3-1.6 mm (median = 1.4 mm), SW: 1.4-1.5 mm (median = 1.4 mm), (n = 11).

Differential diagnosis.

This new species can be distinguished from all congeners (especially the most similar S. albanicus albanicus ) by the clearly visible spiral striation, roughly sculptured protoconch and thickened parietal callus. All Virpazaria species possess an elevated parietal callus, but it is sharp in most (all?) species, and the aperture of those species are more slender, crescent-shaped.

Variation among specimens.

The degree of the thickness of the parietal callus shows some recognisable variability within the single known population, but this trait might be due to the age (degree of development) of the examined shells.

Etymology.

This new species is named after its resemblance to Virpazaria species based on the thickened parietal callus.

Distribution.

Spelaeodiscus virpazarioides sp. n. is known from the type locality only (see also Figure 7 ).

Remarks.

Initially we considered placing this species to the genus Virpazaria due to the thickened parietal callus, which was mentioned in the original description of the genus Virpazaria . However, the subcircular/triangular aperture indicates that it is better to be placed in Spelaeodiscus .

Formerly, this population was incorrectly referred to as S. albanicus and was taken into consideration in that species’ Red List assessment ( Reischütz and Fehér 2017)

Conservation status.

To our present knowledge this species is very rare (currently known from a single location) and thus AOO is smaller than 20 km2. However, there is no reason to suppose that AOO, EOO, number of locations, number of subpopulations or the number of mature individuals are declining or extremely fluctuating. Therefore, it might be assessed as Near Threatened (NT).

Figures

Figure 7. Distribution of Spelaeodiscus Brusina, 1886 species.

Figure 14. Shells of Spelaeodiscus. A-F Spelaeodiscus unidentatus acutus ssp. n., holotype (HNHM 103252) G-L Spelaeodiscus unidentatus acutus ssp. n., Albania, rocks north of Hajmel at the bridge (NHMW 112371) M-R Spelaeodiscus virpazarioides sp. n., holotype (HNHM 103417).