Spelaeodiscus densecostatus Pall-Gergely & A. Reischuetz, 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 densecostatus Pall-Gergely & A. Reischuetz sp. n. Figure 5M-R

Type material.

Montenegro, Hotel/Restaurant Izvor north of Sutomore, no GPS available, leg. A. Reischütz, N. Reischütz & P. L. Reischütz, May 2015, NHMW 112364 (holotype: SW = 3.7 mm, SH = 1.8 mm, Figure. 5M-R), REI/1 juvenile/broken paratype.

Type locality.

Montenegro, Hotel/Restaurant Izvor north of Sutomore.

Diagnosis.

A large species with very low and dense ribs; aperture toothless.

Description.

Spire slightly elevated; protoconch consists of slightly more than 1.5 whorls, rather glossy; teleoconch with very fine, low, equidistant riblets (approx. 112 on the body whorl); between main ribs some fine wrinkles discernible; entire shell with 3.75 whorls; aperture semilunar, peristome; peristome expanded and slightly reflected on the basal and umbilical areas; aperture toothless; umbilicus regular funnel-shaped, relatively wide.

Measurements. SW = 3.7 mm, SH = 1.8 mm, AW = 1.5 mm, AH = 1.4 mm (holotype).

Differential diagnosis.

Spelaeodiscus densecostatus sp. n. differs from S. albanicus by the smaller shell and the much denser and lower ribs on the teleoconch. Furthermore, S. albanicus albanicus has two basal and a palatal tooth in the aperture.

Variation among specimens.

The only known adult shell is the holotype. Therefore, the morphological diversity within population is unknown.

Etymology.

This new species is named for its dense ribs, which distinguishes it from the most similar S. albanicus .

Distribution.

This species is known from the type locality only (Figure 7 ).

Conservation status.

The number of known locations of this species is less than five (i.e. known from a single site) and AOO is smaller than 20 km2, but 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 should be assessed as Near Threatened (NT).

Figures

Figure 5. Shells of Spelaeodiscus Brusina, 1886 species. A-F Spelaeodiscus albanicus edentatus ssp. n., holotype (NHMW 112360) G-L Spelaeodiscus albanicus edentatus ssp. n., Montenegro, rocks across the road at Vitoja, Skadarsko Jezero (NHMW 112361) M-R Spelaeodiscus densecostatus sp. n., holotype (NHMW 112364).

Figure 7. Distribution of Spelaeodiscus Brusina, 1886 species.