Siciliaria tiberii tiberii (A. Schmidt, 1868)

De Mattia, Willy, Reier, Susanne & Haring, Elisabeth, 2021, Morphological investigation of genital organs and first insights into the phylogeny of the genus Siciliaria Vest, 1867 as a basis for a taxonomic revision (Mollusca, Gastropoda, Clausiliidae), ZooKeys 1077, pp. 1-175 : 1

Siciliaria tiberii tiberii (A. Schmidt, 1868)

Figs 1.F, 25.1-25.2, 26.1-26.5, 29.1-29.3

Clausilia tiberii Schmidt 1868: 40.

Clausilia tiberiana Benoit 1876: 152.

Siciliaria tiberii - Boettger 1877: 33.

Siciliaria (Siciliaria) tiberii - Nordsieck 1979: 259.

Charpentieria tiberii - Beckmann 2004: 188.

Charpentieria (Siciliaria) tiberii tiberii - Nordsieck 2007: 54.

Siciliaria tiberii - Welter-Schultes 2012: 343.

Siciliaria tiberii - Nordsieck 2013b: 8.

Charpentieria tiberii - De Mattia 2017f.

Specimens examined.

Italy, Sicily, Terrasini, Capo Rama , 30 m asl, 38°08'19.06"N, 13°03'14.01"E, [Lab ID 19_1, COI: MW758919 , ITS2: MW757116, MW757117 ; Lab ID 19_2, COI: MW758920 ], W. De Mattia and J. Macor leg., 16.xii.2007. 3 dissected spm .

Shell

(Figs 26 .1-26.5, 29.1-29.3). Shell decollate; whorls ribbed; dorsal keel prominent; inferior lamella high to very high; anterior upper palatal plica strong and long, separated from the lunella; sometimes the anterior upper palatal plica presents a distal knob, sometimes another lower weak upper palatal plica is present close to the ALPP; anterior lower upper palatal plica strong and long; palatal edge of clausilium plate distally not receding, palatal edge distally more or less strongly bent upwards.

Measurements

(n = 40, decollate): shell height 16.3 ± 1.2, whorl width 4.0 ± 0.1, aperture height 3.1 ± 0.2, aperture width 2.3 ± 0.2.

External morphology of the genital organs

(Fig. 25 .1). The FO is longer than the V (FO/V range 2.0-2.3). The VD is thin along its whole course except for the proximal part where it is larger in diameter. The FDBC is longer than the BC+SDBC (FDBC/BC+SDBC range 1.5-1.7). The BC+SDBC is club-like to cylindrical and slightly longer than the V (BC+SDBC/V range 1.2-1.5), with no clear distinction between the SDBC and the BC. The apex is big and rounded. The D is slightly longer than the V (D/V range 1.7-1.9) and slightly longer that the BC+SDBC (D/BC+SDBC range 1.1-1.5), thinner than the BC+SDBC and with a small and round apex. The V is big and cylindrical. The A is large and long. The PC is longer than the V (P+E/V range 2.9-3.4). The PR is very short and robust. The ET is clearly visible. The E is longer than the P (E/P range 1.1-1.7) and gradually shrinking and turning into the VD.

Internal morphology of the genital organs

(Fig. 25 .2). The A shows few fleshy weak irregular folds. The P presents a set of transverse smooth pleats. The pleats are slightly irregular and tend to fade towards the A. The penial wall is smooth. The PP is big, elongated and markedly wrinkled with a pointed apex. It originates from one transverse epiphallar ring. The E shows two main fringed pleats that run as far as the VD. The V shows a weak irregular pattern of smooth pleats.

Ecology.

Siciliaria tiberii tiberii is found under stones, among scree, rocky debris and on dry stonewalls along the coastline, on a limestone plateau. According to De Mattia (2017f), the taxon is Near Threatened.

Distribution.

Beckmann (2004: 188), following Nordsieck’s personal communications cites Siciliaria tiberii tiberii from a southern area surrounding San Cipirello (Madonna dei Furi, Monte Palmeto, Monte della Fiera, San Giuseppe Jato and Monte della Scala). As previously stated, this identification revealed to be wrong.

As a result, the actual distributional range of Siciliaria tiberii tiberii seems to be limited to the area from San Cataldo (Partinico) in the south to Monte Palmeto and Capo Rama (Terrasini) in the north to the northern slopes of Monte Pecoraro. Further field research is needed in order to define its actual distribution. Recent findings of Diego Viola (Trieste, Italy) from a locality between San Giuseppe Jato and Piana degli Albanesi revealed the presence of a population of Siciliaria cfr. Siciliaria tiberii that clearly differ, as a shell, from S. calcarae jatinensis ssp. nov. and S. calcarae parajatinensis ssp. nov.(personal communication). The poor samples available (few damaged shells) did not allow us a thorough investigation.

Remarks.

Monte San Calogero in the east (cited by Nordsieck as also included in the S. tiberii distribution), is an isolate limestone massif 10 km SE of Termini Imerese, 50 km east of San Cipirello and 65 km SSE of Capo Rama. The presence of S. tiberii tiberii in this locality, due to its remarkable distance, should be confirmed by further field research and not only inferred from museum samples. Mislabelling or wrong locality assignments could have played a role in this regard (as for Siciliaria septemplicata alcamoensis , see below). The diagnosis provided by Nordsieck (2013b: 8) "Shell not or only in part decollate; dorsal keel less strong" imply that it might represent another population of S. calcarae s. l., yet more field and taxonomical research is needed. Clausilia tiberiana Paulucci 1878 is deemed as junior synonym of Siciliaria tiberii tiberii by Nordsieck (2013b: 8). The authorship is probably wrong as Paulucci (1878: 13) cites Clausilia tiberiana Benoit: Benoit (1875: 152) introduced the name Clausilia tiberiana as a "Elegante e bella specie de’ dintorni di S. Giuseppe delle Mortelle contrada non lungi da Palermo" and depicted this taxon in 1876 (Table VI, fig. 7). Benoit (1881: 107) stated that again that "Questa bellissima e grande conchiglia, non conosciuta dagli autori siciliani vive nella contrada detta S. Giuseppe delle Mortelle, non lungi da Palermo". Despite intensive collecting in the surrounding of Palermo by one of the authors (WDM), we were unable to identify the position of this old toponym (also by asking locals).

Figures

Figure 1. Wagner's (1913, 1925) and Brandt's (1961) Siciliaria genital drawings A Siciliaria septemplicata, Wagner, 1913: plate 572, fig. 14 B Siciliaria grohmanniana grohmanniana, Wagner, 1925: plate 1, fig. 8 C Siciliaria calcarae calcarae, 1925: plate 3, fig. 25 D Siciliaria ferrox, Brandt, 1961: fig. 1 E overall Siciliaria / Sicania and Sicilian Mauritanica distribution F Siciliaria / Sicania and Sicilian Mauritanica distribution of taxa.

Figure 25. Siciliaria tiberii tiberii (A. Schmidt, 1868), Capo Rama, Terrasini 25.1 whole distal genital organs 25.2 internal distal part of genital organs. Siciliaria tiberii alcamoensis Brandt, 1961 comb. nov., Piano Margi, Carini 25.3 whole distal genital organs 25.4 internal distal part of genital organs 25.5 detail of the pseudopapilla.

Figure 26. Siciliaria tiberii tiberii (A. Schmidt, 1868), Capo Rama, Terrasini 26.1 shell 26.2 clausiliar plate double side 26.3 shell 26.4 detail of the aperture 26.5 clausiliar plate double side. Siciliaria tiberii alcamoensis Brandt, 1961 comb. nov., Piano Margi, Carini 26.6 shell 26.7 clausiliar plate double side 26.8 detail of the aperture 26.9 shell.