Renea kobelti (A. J. Wagner, 1910 )

Lika, Romilda, Deli, Tamás, Paparisto, Anila, Erőss, Zoltán P. & Fehér, Zoltán, 2021, Contribution to the taxonomy and distribution of Aciculidae (Mollusca: Gastropoda: Caenogastropoda) in Albania and the surroundings, Zootaxa 5004 (1), pp. 131-150 : 145-148

Renea kobelti (A. J. Wagner, 1910)

Figs 9A–K

* Acme kobelti A. J. Wagner 1910: 187 , pl. 16, figs 17–18.

Renea kobelti albanica Boeters, E. Gittenberger & Subai, P. 1989: 189 , figs 194, 197, 208.

Renea kobelti kobelti ( Wagner, 1910) — Boeters, H.D., Gittenberger, E. & Subai, P. 1989: 188, figs 193, 195–196, 208.

Renea (Pleuracme) kobelti (A. J. Wagner, 1910) —Zilch, A. 1976: 129, pl. 12a, fig. 20.

Diagnosis. Shell slender fusiform, somewhat tapering, horn-brown (old empty shells are white) with 6¼–7½ convex whorls. The body whorl is apparently flatter than the upper ones. Protoconch (¾–1½ whorls) smooth, teleoconch strongly ribbed. Apertural rim asimmetrically arched in side view: its upper part leans deeper backwards than the lower part. A sinulus is not clearly marked.A neck bulge is missing. Peristome moderately thickened. Parietal callus is visible, sometimes its anterior part emerges like a weak parietal flap; this flap reaches the columella but does not reach the palatal insertion is developed as a n upstanding ridge; but ends in the weak angular tooth before reaching the palatal insertion. Umbilicus is covered.

Dimensions. H: 4.10–5.70 mm (it is estimated that full grown specimens of the Laç population exceed 6 mm); W: 1.40–2.10 mm; H b: 1.90–2.75 mm; W b: 1.30–1.85 mm; H a: 1.15–1.70 mm; W a: 0.80–1.20 mm.

Type material studied. Lectotype (of Acme kobelti ): Montenegro, ’Im Mulm der Kalkfelsen von Kameno, oberhalb Castelnuovo in Süd-Dalmatien’ [cliffs at Kameno, above Herceg-Novi]; Wagner leg.; IZPAN 5497 (designated by Boeters et al. 1989). Holotype (of Renea kobelti albanica ): Albania, ’Felsen an der Quelle Byshek südöstl. von Elbassan am Skumbi’ [Byshek Spring near Elbasan]; NHMW-75000/E 16535. Paralectotypes (of Acme kobelti ): 10 shells; same collection data as for the lectotype of Acme kobelti ; IZPAN 5497. 2 shells; same collection data as for the lectotype of Acme kobelti ; SMF 32577. Paratypes (of Renea kobelti albanica ): 2 shells; same collection data as for the holotype of Renea kobelti albanica ; NHMW- 75000/E 16535b. Albania, ’Skutari am rechten Ufer des Flusses Kiri’ [near Shkodër, right bank of Kir River]; NHMW- 79000/ K 53206 . 1 shell, Montenegro, Virpazar; Dabović leg.; NHMW- 75000/ E 48623 .

Additional material: Albania, Laç district , Laç , beneath Shna Ndout (St. Antony) Church, cliffs along the footpath; 41.6318° N, 19.7297° E; 225 m alt.; 14 Jul 2018; Z. Fehér, T. Fehér and R. Lika leg.; HNHM 104672 . Albania, Tepelenë district , Këlcyre W 7 km, a cave near Peshtan junction; 40.2971° N, 20.1077° E; 150 m alt.; 11 Jul 2019; Z. Barina, F. Bego, Z. Fehér, T. Fehér, A. Lindon, M. Mecsnóber, G. Puskás and T. Szederjesi leg.; HNHM 104674 . Montenegro, Kameno bei Castelnuovo Süddalmatien; NHMW 47812 . Montenegro, Plateau von Kameno; ex. Käufel; NHMW-79000 / K 15574 . Montenegro, Orjen Mts , between Podi and Kameno on the old Herceg Novi–Trebinje road; 42.4746° N, 18.5358° E; 420 m alt.; 17 Jul 2018; Z. Erőss, T. Fehér and Z. Fehér leg.; HNHM 104673 . Montenegro, Kotor , Škurda Gorge and N slope of the fortress; 42.4269° N, 18.7756° E; 75 m alt.; 29 May 2015; T. Deli, Z. Erőss and Z. Fehér leg.; HNHM 104670 . Montenegro, Lovćen Mts , gorge ca. 8 km from Kotor on the Kotor–Njeguši road; 42.4022° N, 18.7751° E; 400 m alt.; 29 5 2015; T. Deli, Z. Erőss and Z. Fehér leg.; HNHM 104671 . Montenegro, ’ Ljutaquelle bei Kotor’ [Ljuta Spring at Dobrota]; ex. Kuščer; NHMW-75000 /E 49328 .

Distribution. It was previously known from the Mt. Orjen above Herceg Novi, the Kotor Bay area the Shkodër Basin and the Byshek Spring at Central Albania. Newly found localities extend the known range to southern Albania.

The item from Virpazar (NHMW-75000/ E 48623 ) is worth of some further discussion. This sample was collected by Petar Dabović in the 1930s, passed somehow to the Viennese private collector, Aemilian Edlauer and finally landed in the NHMW Mollusc Collection. Virpazar is a small historical town with a fortress. In the past decades, various malacologists sampled in and around Virpazar, including E. Gittenberger, H. Nordsieck, A. and P. L. Reischütz, P. Subai and the authors of this paper, but none was able to refind this species. The case is similar to those of Virpazaria backhuysi E. Gittenberger, 1969 , Virpazaria ripkeni E. Gittenberger, 1969 or Agathylla biloba (A. J. Wagner, 1914) , which species also have samples in the NHMW from Virpazar according to label information, arrived from the Edlinger collection, and originally collected by P. Dabović, but also them have never been refound in or around Virpazar (see Fehér et al. 2014, 2019). This either means that their label information refers to the Virpazar area in the broader sense or we can not exclude the possibility of mislabelling. Both might discredit the validity of this locality record.

Remarks. When R. kobelti albanica was described, the nominate form was known from two locations (Kameno and the Ljuta Spring), and there were three other samples (Virpazar, Kir River and Byshek Spring) with six individuals of which only one from each site was full grown. Boeters et al. 1989 claimed that these individuals are larger sized, slenderer, denser ribbed and have more smooth embrional whorls. We had the opportunity to study further samples from the Kotor Bay, from northern and southern Albania.

In Laç we could not obtain intact specimens, all what we have are either juveniles or decollated/damaged adults. Therefore, we compared dimensions and rib density values of the body whorl across the available populations. W b and H b values strongly correlate (linear regression R 2 =0.93), i.e. higher individuals are also wider and vice versa. Smallest individuals are from the type locality of the nominate form (Kameno), largest ones are from Laç. Extrapolating from the body whorl dimensions, their shell height values might be estimated from 5.5 to 6.5 mm. The holotype from Byshek Spring is of the same size as the smallest individuals in Laç. The other two R. kobelti albanica are even smaller. Rib density seems to be independent from shell dimensions ( Fig. 10 .). The Virpazar and Byshek specimens are really denser ribbed than the average, but also in Laç there was a shell, ribbed in the same way. The densest ribbed shells are from Kelcyrë. Some of the Kameno specimens are really widely-ribbed, but not all. H b: W b ratio varies between 1.35 and 1.52, stoutest individuals are in Kelcyrë but the populations can not be clearly distinguished by this character.

Summing up, the height/width ratio and rib density values were found to vary within-population too much to be good distinguishing features. Moreover, the newly found Albanian populations confuse the clear geographic pattern claimed by Boeters et al. 1989 as the southernmost Kelcyrë population resembles the most to the typical R. kobelti from Kameno. Although the absolute dimensions vary between populations, there are no features to clearly distinguish two or more taxa, therefore, R. kobelti albanica should be considered as the synonym of the nominate form.

Conservation status. At the time of the global assessment, the number of all known locations was five, and having no specific threat on this species it was assessed as Near Threatened (NT) ( Fehér 2011d). Due to recently discovered new locations, the number of known subpopulations is above five globally, but individually in Albania and in Montenegro remains below five. Accordingly, the global assessment needs to be reconsidered to Least Concern (LC), but the national assessements both for Albania and for Montenegro should be Near Threatened (D2).

Figures

FIGURE 9. Shells of Renea kobelti (A. J. Wagner, 1910). A–B. Byshek Spring, holotype of R. kobelti albanica (NHMW- 75000/E 16535). C–D. Virpazar, paratype of R. kobelti albanica (NHMW-75000/E 48623), E–F. Kelcyrë W 7 km (HNHM 104674). G–H. Bank of Kir River, paratype of R. kobelti albanica (NHMW-79000/K 53206). I–K. Laç (HNHM 104672) note that I and J are the same decollated specimen, whereas K illustrates the upper whorls of a not fully grown shell. L–M. Kameno (HNHM 104673). Scale bar = 1 mm.

FIGURE 10. Comparing conchological characters of Renea kobelti populations. A. Body whorl width plotted against body whorl height. B. Body whorl width plotted against the size of 10 rib spaces (see Fig. 2). Blue dots: Laç; red diamonds: Byshek Spring, holo- and paratype of Renea kobelti albanica; green triangles: Kelcyrë; black square: Bank of Kir River, paratype of R. kobelti albanica; white squares: Kameno, type locality of Renea kobelti; Drisht; orange squares: Kotor; blue diamond: Virpazar, paratype of R. kobelti albanica. Absolute dimensions are in mm.