Spelaeodiscus latecostatus Pall-Gergely & Eross, 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 latecostatus Pall-Gergely & Eross sp. n. Figure 10F-O

Type material.

Montenegro, S of Virpazar, 0.8 km (in a straight line) E of Limljani, above the village, 400 m a.s.l., 42°11.698'N, 19°06.217'E (site code: 20171021B), leg. T. Deli, Z.P. Erőss, A. Hunyadi & B. Páll-Gergely, 21.10.2017, HNHM 103214 (holotype, Fig. 10A-E ).

Other material.

Montenegro, Seoća S 1 km, along the Virpazar-Ostros road, 280 m a.s.l., 42°12.618'N, 19°9.000'E (site code: 2017/005), leg. Z.P. Erőss & Z. Fehér, 16.07.2017, HNHM 103213/3 shells, not paratypes (Fig. 10K-O ) .

Type locality.

Montenegro, S of Virpazar, 0.8 km (in a straight line) E of Limljani, above the village, 400 m a.s.l., 42°11.698'N, 19°06.217'E (site code: 20171021B).

Diagnosis.

A small, nearly flat species with strong, very widely spaced ribs, glossy protoconch and a toothless aperture.

Description of the holotype.

Spire somewhat elevated; protoconch consists of ca 1.25-1.5 whorls (the holotype is corroded at the protoconch-teleoconch junction), rather smooth, moderately glossy; teleoconch with very strong, equidistant, widely spaced ribs (42 on the body whorl); between main ribs some fine wrinkles discernible; entire shell with 3.75 whorls; aperture semilunar, toothless; peristome slightly thickened and expanded; umbilicus funnel-shaped, relatively narrow.

Measurements. SW: 2.2 mm, SH: 1.2 mm, AW: 0.8 mm, AH: ca. 0.8 mm, AA = 63°(holotype).

Differential diagnosis.

The widely spaced ribs are similar to S. hunyadii sp. n., but the less oblique aperture distinguishes S. latecostatus sp. n. from the other new species. Spelaeodiscus dejongi , which lives sympatrically with S. latecostatus sp. n., is similar in shell shape and size and the formation of the aperture, but has much denser ribs.

Variation among specimens.

See remarks.

Etymology.

This new species is named after its remarkably widely spaced ribs.

Distribution.

See under Remarks and Figure 7 .

Remarks.

The holotype of this species was found in a large sample of S. dejongi . Therefore, even if the shell shape does not differ from that species, the widely spaced ribs indicate that S. latecostatus sp. n. differs from S. dejongi on species level. Three shells from 1 km S of Seoća possess denser ribs than other S. dejongi populations (47-54 ribs on the body whorl), but obviously the rib density is lower than that of the holotype of S. latecostatus sp. n. Since the rib density of that population is intermediate between S. dejongi and S. latecostatus sp. n., it is not possible to decide which species it belongs to. More populations around the sample from 1 km S of Seoća site are necessary in order to provide a reliable identification. Here we provisionally identify those shells as Spelaeodiscus cf. latecostatus sp. n.

Conservation status.

To our present knowledge this species is very rare (currently known from two locations) 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 10. Shells of Spelaeodiscus Brusina, 1886 species. A-E Spelaeodiscus hunyadii sp. n., holotype (HNHM 103210) F-J Spelaeodiscus latecostatus sp. n., holotype (HNHM 103214) K-O Spelaeodiscus cf. latecostatus sp. n., Montenegro, Seoca S 1 km (HNHM 103213).