Platyla procax Boeters, E. Gittenberger & Subai, 1989

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 : 139-142

Platyla procax Boeters, E. Gittenberger & Subai, 1989

Figs 7A–M

* Platyla procax Boeters, E. Gittenberger & Subai, P. 1989: 157 , figs 110, 153-154.

Platyla corpulenta Subai, 2009: 104 , figs 2, 5.

Platyla procax Boeters, E. Gittenberger & Subai, 1989 —Subai, P. 2009: 104.

Platyla procax Boeters, E. Gittenberger & Subai, 1989 —Welter-Schultes, F.W. 2012: 82.

Platyla corpulenta Subai, 2009 —Welter-Schultes, F.W. 2012: 78.

Diagnosis. Shell oval-conical, translucent (elder empty shells are white). Body whorl occupies (calculated as the Hb /H ratio) more than half of the total shell height. 5–6 moderately convex whorls, regularly increasing. Teleoconch smooth, with only a few irregularly standing growth lines. Aperture acutely oval in frontal view. Parietal callus thin, umbilicus covered, apertural rim is simmetrically and just slightly arched in side view. Angularis reduced or missing, sinulus not visible. Neck bulge is weakly developed or missing.

Dimensions. H: 2.95–4.30 mm; W: 1.35–1.90 mm; H b: 1.65–2.35 mm; W b: 1.25–1.70 mm; H a: 1.05–1.45 mm; W a: 0.75–1.10 mm; H b /H: 0.5–0.6.

Type material studied. Holotype (of P. procax ): Montenegro: Radetina pećina near Ilijino brdo; 1300 m alt.; Dabović leg.; NHMW-75000/E 49291a. Holotype (of P. corpulenta ): Montenegro, S side of Mt. Kroništar, ca. 10 km E of Ðuravci on the road to Ostros), in crevices of limestone rock and rock cavities; 350 m alt.; 21 Sep 2005; Subai leg.; SMF 329428. Paratypes (of P. procax ): 3 shells; same collection data as for the holotype of P. procax ; NHMW- 75000/E 49291b. Paratypes (of P. corpulenta ): 1 shell; same collection data as for the holotype of P. corpulenta ; NMBE 531621/1. 10 shells; Montenegro, near the previous location; 500 m alt.; 16 Sep 2006; Subai leg.; NMBE 531624/10. 2 shells; Montenegro, Rumija Mts., 4 km S of from Arbneš/Arbneshi (= approx. 2 km S of the mountain pass), 350 m alt.; 21 Sep 2005; Subai leg.; NMBE 531622/2. 6 shells; same locality as for preceding; 16 Sep 2006; Subai leg.; HNHM 96782/1, NMBE 531623/5.

Additional material. Albania: Shkodër district, Mt. Tarabosh, Vallas, Burimi i Vjetër ; 42.0500° N, 19.4160° E; 160 m alt.; 27 May 2015; T. Deli, Z. Erőss and Z. Fehér leg.; HNHM 101031 . Albania, Shkodër district, Mt. Tarabosh., Vallas , near mosque; 42.0506° N, 19.4162° E; 190 m alt.; 27 May 2015; T. Deli, Z. Erőss and Z. Fe- hér leg.; HNHM 104626 . Albania, Shkodër district, Mt. Tarabosh, above Vallas , S of Tarabosh Peak; 42.0515° N, 19.4171° E; 210 m alt.; 27 May 2015; T. Deli, Z. Erőss and Z. Fehér leg.; HNHM 104627 . Albania, Shkodër district, Drisht, right bank of Kir river opposite to the fortress hill; 42.1304° N, 19.609° E; 90 m alt.; 28 Jun 2016; Z. Erőss, Z. Fehér, M. Szekeres and J. Grego leg.; HNHM 104629 . Albania, Shkodër district, 4 km SW of Prekal ; 42.1656° N, 19.6889° E; 170 m alt.; 28 Jun 2016; Z. Erőss, Z. Fehér, M. Szekeres and J. Grego leg.; HNHM 104630 . Albania, Shkodër district, Drisht, right bank of Kir river at Shpellë Korbe ; 42.125° N, 19.6031° E; 90 m alt.; 14 Jul 2018; Z. Fehér, T. Fehér and R. Lika leg.; HNHM 104633 . Albania, Shkodër district, Zogaj ; 42.0728° N, 19.3932° E; 50 m alt.; 18 Apr 2009; P. Subai leg.; NMBE 531625 . Montenegro, Rumija Mts., Arbnež S 4 km, on the Ostros–Ulcinj road, 2 km S of Štegvaš Pass; 42.0582° N, 19.3535° E; 350 m alt.; 28 May 2015; T. Deli, Z. Erőss and Z. Fehér leg.; HNHM 104628 . same locality as for preceding; 16 Jul 2017; Z. Erőss and Z. Fehér leg.; HNHM 104632 . Monte- negro, Arbnež S 2 km, on the Ostros–Ulcinj road, SW of Štegvaš Pass; 42.0636° N, 19.3710° E; 480 m alt.; 16 Jul 2017; Z. Erőss and Z. Fehér leg.; HNHM 104631 .

Distribution. Mountains surrounding the southwestern and southeastern part of the Shkodër Basin (Mt. Rumija, Mt. Kroništar, Mt. Tarabosh and the westernmost extension of the Prokletije Mts) ( Fig. 1B ). In the original description of P. corpulenta, Subai (2009) mentions a locality at Arras, far to the east of the Shkodër Basin. However, that material was proved to be a juvenile P. albanica .

Remarks. At the time of the description of P. corpulenta , there were only four known P. procax specimens from one location and only nine adult P. corpulenta specimens from two locations (see notes at Distribution about the identity of the third P. corpulenta population mentioned by Subai (2009). Based on this, Subai (2009) treated P. corpulenta as a distinct species, which has a larger (H of P. procax : 3.25–3.65 mm whereas H of P. corpulenta : 3.68–4.3 mm) and relatively broader shell, a larger aperture, a better arched apertural rim and not any neck bulge.

Since then, further specimens from more locations became available. Taking all of them into account an apparent overlap is found both in absolute sizes and in relative stoutness (W/H ratio) values. Neither the presence/absence of a weak neck bulge proved to be a reliable distinguishing feature: this feature considerably varies within populations whenever a larger set of shells are studied. Although the P. procax paratype specimen, illustrated in side-view by ( Boeters et al. 1989: fig. 154b = Fig. 7C ) has an apparent neck bulge, the holotype has hardly any ( Fig. 7B ). And also, some of the larger and stouter, typical corpulenta -like individuals also bear a neck bulge (e.g. Figs 7I, 7K ).

Based on these new findings, it seems unjustified to further distinguish P. procax and P. corpulenta , so we suggest to treat the latter as the junior synonym of the former one.

Conservation status. According to the latest global assessments ( Fehér 2011b, 2018b), P. procax was classified as Vulnerable D2 and P. corpulenta as Least Concern. In the light of new distributional data and according to this new taxonomical concept, P. procax has more than five known locations/subpopulations globally and its area of occupancy (AOO) is supposed to be above 20 km 2. As there is no reason to suppose that the habitat quality, area of occupancy (AOO), number of locations, number of subpopulations or the number of mature individuals are declining or extremely fluctuating and there are no specific threats to this species, it qualifies for the Least Concern (LC) category at the global level. At the country level, however, there are less than five known locations and less than 20 km 2 AOOs both in Albania and Montenegro. Hence, at the national level it classifies as Near Threatened for both countries.

Figures

FIGURE 1. Distribution of Platyla and Renea species in and around Albania. A. Yellow: P. albanica; yellow star: type locality of P. albanica; red: P. feheri; red triangle pointing up: type locality of P. feheri. B. Black: P. banatica; red: P. pinteri; red triangle pointing up: type locality of P. pinteri; magenta: P. procax; magenta star pointing up: type locality of P. corpulenta; magenta star pointing down: type locality of P. procax. C. White: P. gracilis; white star: type locality of Acicula graeca; magenta: R. kobelti; magenta star pointing up: type locality of R. kobelti; magenta star pointing down: type locality of R. kobelti albanica. D. Red: P. similis; red star pointing up: type locality of Hyalacme beieri; red star pointing down: type locality of Platyla ceraunorum; purple: P. wilhelmi; purple star: type locality of P. wilhelmi.

FIGURE 7. Shells of Platyla procax Boeters, E. Gittenberger & Subai, 1989. A–B. Radetina pećina near Ilijino brdo, holotype (NHMW-75000/E 49291a). C. Radetina pećina near Ilijino brdo, paratype (NHMW-75000/E 49291b). D–F. Vallas (HNHM 104627). G. Prekal SW 4 km (HNHM 104630). H–I. Štegvaš Pass S 2 km (HNHM 104628). J–K. Drisht (HNHM 104633), L–M. Štegvaš Pass S 2 km (HNHM 104628). Scale bar = 1 mm.