Platyla similis ( Reinhardt, 1880 )

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 : 142-144

Platyla similis ( Reinhardt, 1880)

Figs 6A–N

* Acme similis Reinhardt 1880: 46 .

Acme transsilvanica A. J. Wagner 1912: 258 .

Hyalacme beieri Käufel, 1930: 166 , fig. 3.

Platyla ceraunorum A. Reischütz, N. Steiner-Reischütz & P. L. Reischütz 2016: 82 , figs 2a–c.

Acicula (Hyalacme) beieri (Käufel) —Klemm, W. 1962: 219.

Acicula (Hyalacme) transsilvanica (A. J. Wagner) —Klemm, W. 1962: 219.

Acicula (Hyalacme) similis (Reinhardt) —Pintér, L. 1968: 211, figs 24–25.

Acicula (Hyalacme) beieri (Käufel) —Subai, P. 1976: 122, fig. 5.

Acicula (Hyalacme) beieri ( Käufel, 1930) —Zilch, A. 1976: 128.

Acicula (Hyalacme) similis ( Reinhardt, 1880) —Zilch, A. 1976: 128, pl. 12, fig. 17.

Platyla similis ( Reinhardt, 1880) —Boeters, H.D., Gittenberger, E. & Subai, P. 1989: 159, figs 157, 160, 162–165.

Platyla similis ( Reinhardt, 1880) —Welter-Schultes, F.W. 2012: 82, unnumbered fig.

Diagnosis. Shell slender fusiform, colourless to horn-brown, with 4½–6 slightly convex whorls. In frontal-view, body whorl usually occupies less than half of the total shell height (Hb/H ratio is around 0.5). Aperture in the frontal view angular to rounded oval, with a characteristic sinulus. Parietal callus clearly recognizable, passing into the columella; Angularis is missing. Umbilical callus very thin, extends up to about the middle of the parietal wall. In side-view, the upper part of the aperture stands slightly upwards; apertural rim is asymmetrically arched: the most pronounced part is located higher than the mid-line, and the rim leans backwards steeper above this than below. Sometimes (but not always) there is a neck bulge-like structure behind the apertural rim: a not clearly delimited, vague swelling.

Dimensions. H: 1.80–2.40 mm; W: 0.60–0.85 mm; H b: 0.90–1.15 mm; W b: 0.55–0.70 mm; H a: 0.55–0.70 mm; W a: 0.40–0.50 mm.

Type material studied. Holotype (of Hyalacme beieri ): Greece, Lefkas Island , Kaligoni; 14 Apr 1929; Beier leg., NHME-79000/K-15565 . Holotype (of Platyla ceraunorum ): Albania, Vlorë district, Himarë community, Kudhës, stream debris at the bridge along the old SH8 road to Pilur ; May 2015; A. Reischütz, N. Reischütz and P.L. Reischütz leg.; NHMW 111145 . Paratypes (of Hyalacme beieri ): 1 shell; Greece, Lefkas Island , Kaligoni; 14 Apr 1929; Beier leg.; NHMW-79000 /K-15564 .

Additional material: Albania, Sarandë district, S of Ilias, 300 m from the main road to Stavridi Monastery ; 40.1446° N, 19.6744° E; 253 m alt.; 12 Jul 2019; Z. Fehér and T. Fehér leg.; HNHM 104634 . Greece, Lefkas Island, Kaligoni ; 20 Apr 1932; M. Beier leg. (ex. coll. A. Fuchs); NHMW-79000 / K-6706. same locality as for preceding; M. Beier leg.; NHMW-75000 /E 28625 [erroneously labelled as syntype]. same locality as for preceding; M. Beier leg.; NHMW-79000 /K-6701 [label erroneously indicates type status]. Greece, Lefkas Island, above Poros ; 30 Jul 1976; L. Pintér and P. Subai leg.; HNHM 74013 . Greece, Corfu Island, between Barbati and Nissaki , side of Mt. Pantokrator ; 39.725° N, 19.88° E; 20 Jul 1975; P. Subai leg.; HNHM 69774 . Greece, Nisista ; 6 Jun 1933; M. Beier leg.; NHMW-79000 /K-6708. Greece, ’ Platanusa’ [=Platanoussa]; 4 Jun 1933; M. Beier leg.; NHMW- 79000 /K-6709. Greece, Drama county, Dytiki Rodopi, 13 km E of Sidironero, debris of Georuadi Stream ; 41.3654° N, 24.3247° E; 525 m alt.; 1 Apr 2007; L. Dányi, Z. Erőss, Z. Fehér, J. Kontschán and D. Murányi leg.; HNHM 104635 . Kosovo, Kačanik [Kaçanik], beech forest; NHMW 44425 .

Remarks. Max Beier visited Kaligoni first in 1929, which trip was followed by two further ones in 1932 and 1933. Käufel (1930) described Hyalacme beieri on the basis of two specimens collected during the first visit. The material of the following two collecting events were studied by Klemm (1962), who claims that further 26 specimens were found in 1932 and 1933. It is logical to conclude that the museum items NHMW-75000/E 28625 and NHMW-79000/K-6701, labelled without dates but with the indication of locality as Kaligoni, must came from 1932 or 1933, and as such, they must not be types.

Klemm (1962) determined the material from Nisista (NHMW-79000/K-6708) and Platanoussa (NHMW-79000/ K-6709) as Acicula transsilvanica , whereas that from Kaligoni as Acicula beieri . At the same time, Klemm (1962) notes that the elongated shell, attributed to Acicula beieri by Käufel, is not generally characterize this population; apart from the holotype each specimens’ shell height is in the 1.9–2.0 mm range. Later, Boeters et al. (1989) synonymized both beieri and transsilvanica under Platyla similis .

Shell characters of the two recently found South Albanian populations, one of them described as P. ceraunorum by Reischütz et al. (2016), seem to fell within the intra- and inter-population variability of this species. Accordingly, we should treat P. ceraunorum as the synonym of P. similis .

Sysoev & Schileyko (2009) mention the name Platyla similis as a junior synonym of Platyla oedogyra ( Paladilhe, 1868) without providing any justification, and MolluscaBase (2021) follows this (mis)interpretation. This is somewhat difficult to understand, especially in the light of the fact that the systematic position of P. oedogyra was investigated very thoroughly by Boeters et al. (1989) and they came to the conclusion that P. oedogyra is a junior synonym of Platyla polita ( Hartmann, 1840) . The P. oedogyra specimen, illustrated by Sysoev & Schileyko (2009: fig. 2d) exhibits very similar characters of P. polita and does not resemble P. similis at all. Thus, we see no reason to depart from the concept of Boeters et al. (1989) and therefore, we consider P. similis as a valid name and P. oedogyra as the junior synonym of P. polita .

Distribution. This species is patchily distributed within a relatively wide range ( Boeters et al. 1989). The range includes the Appennines down to southern Italy and Sicily, the Southern Carpathians in Romania, the Stara Planina Mts. in Bulgaria and eastern Serbia, the Rhodope Mts. in southern Bulgaria and northeastern Greece (e.g. Fig. 6M ), the southern part of Serbia, the Shar Mts. in Kosovo, the Ionian Islands, and the Ionian coast from southern Albania down to the Peloponnese ( Fig. 1D ).

Conservation status. Globally it was assessed as Least Concern (LC) because of the relatively large range, numerous known subpopulations and no identified threats ( Páll-Gergely 2011). Neither in Albania is there any reason to suppose that the habitat quality, extent of occurrence (EOO), area of occupancy (AOO), number of locations, number of subpopulations or the number of mature individuals are declining or extremely fluctuating. But there are only two known locations in Albania, and therefore, it qualifies for the Near Threatened (D2) category at the national level.

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 6. Shells of Platyla species. A–N. Platyla similis (Reinhardt, 1880). A–B. Kudhës, holotype of Platyla ceraunorum (NHMW 111145). C–D. Lefkas, Poros (HNHM 74013). E–F. S of Ilias (HNHM 104634). G–H. Lefkas, Kaligoni, holotype of Hyalacme beieri (NHMW-79000/K-15565). I–J. Lefkas, Kaligoni (NHMW-75000/E-28625). K. Nisista (NHMW-79000/K 6708). L. Platanoussa (NHMW-79000/K 6709). M. Sidironero E 13 km (HNHM 104635). N. Kaçanik (NHMW 44425). O–R. Platyla gracilis (Clessin, 1877). O–P. W of Çajup Pass (HNHM 104652). Q–R. Suhë NE 6 km (HNHM 104651). Scale bar = 1 mm.