Siciliaria tiberii armettensis, De Mattia & Reier & Haring, 2021

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 armettensis ssp. nov.

Figs 1.F, 27.1-27.3, 28.1-28.3, 29.6-29.8

Type locality.

Italy, Sicily, Carini, Grotta dei Puntali o dell’Armetta, 90 m asl, 38°8'58.56"N, 13°9'25.83"E.

Type material.

1 Holotype (NHMW 113621) [Lab ID 38_1, COI: MW758880, ITS2: MW757098, MW757099, MW757100] and 4 Paratypes (NHMW 113622): Italy, Sicily, Carini, Grotta dei Puntali o dell’Armetta, 90 m asl, 38°08'58.56"N, 13°09'25.83"E, [Lab ID 38_2, COI: MW758881], W. De Mattia and J. Macor leg., 16.iv.2017. 3 dissected spm. 8 Paratypes (CMWDM 18227): same locality.

Shell diagnosis.

Shell decollate; whorls moderately ribbed; dorsal keel prominent; inferior lamella high; anterior upper palatal plica present, knob present at distal end of the upper palatal plica, detached from the lunella; lower anterior palatal plica (ALPP) present; palatal edge of clausilium plate distally not receding, palatal edge distally strongly bent upwards.

Shell description

(Figs 28 .1-28.3, 29.6-29.8). The shell is elongated, fusiform, sinistral, decollate and robust. It is brown to dark reddish in colour. The shell surface has small ribs, more densely packed towards the decollate tip and gradually spreading towards the aperture. There are whitish papillae along the moderately deep sutures throughout the whole teleoconch. The spire is slowly and regularly growing, with 7 ½ (after decollation) slightly convex whorls. The basal and cervical keels are well distinct. The umbilicus is closed. The aperture is roundish to subovoid and its height is ~ 1/4 to 1/5 of shell height. The PRI is short and it ends at the level of the L. It is not fused with the L and presents a slight thickening along its posterior end. The PRI is not visible from a frontal view of the aperture. The L is dorso-lateral to lateral. The PUPP is short or obsolete, knob-like and connected to the L. The AUPP is strong and long, detached from the L and clearly visible from the aperture. The distal end of the AUPP has a well-developed knob. The BAS starts directly from the L and it is long and strong, well visible from the aperture. The SCL is absent or resembling an irregular small thickening, connected with the lunella. The IL is very high to extremely high. The SUL is tooth-like, long and overlapping with the SPL. The SPL is long and it ends at 4/5 of the last whorl. The SCOL is not visible. The peristome is continuous, markedly thickened and reflected. It is not superiorly fused to the wall of the first whorl. The palatal edge of the clausilium is distally receding and bent upwards. The plate is cylindrical in shape. The palatal edge against the distal end is bent upwards and more or less blunt.

Measurements.

Holotype: decollate shell height 20.1, whorl width 4.8, aperture height 4.6, aperture width 3.1. Paratypes (n = 35, decollate): shell height 19.7 ± 1.6, whorl width 4.6 ± 0.2, aperture height 4.2 ± 0.3, aperture width 2.8 ± 0.3.

External morphology of the genital organs

(Fig. 27 .1). The FO is longer than the V (FO/V range 1.5-1.8). The VD is thin along its whole course. The FDBC is slightly longer than the BC+SDBC (FDBC/BC+SDBC range 1.0-1.3). The BC+SDBC is irregularly spindle-like and longer than the V (BC+SDBC/V range 1.6-1.9), with no distinction between the SDBC and the BC. The apex is pointed. The D is longer than the V (D/V range 3.0-3.2) and longer that the BC+SDBC (D/BC+SDBC range 2.1-2.3), much thinner than the BC+SDBC and with a small but round apex. The V is short, cylindrical and large in diameter. The A is large. The PC is much longer than the V (P+E/V range 2.6-2.8). The PR is short and robust. The ET is not clearly visible. The E is longer than the P (E/P range 1.7-1.9), gradually shrinking and turning into the VD.

Internal morphology of the genital organs

(Figs 27 .2, 27.3). The A shows a set of irregular fleshy folds. The P presents a main longitudinal fleshy fold that goes from the PP as far as the A. This fold is heavily segmented in an oblique way. Additionally, the P also shows a set of small longitudinal and irregular small pleats that reach the A. The fine structure of the wall is smooth. The PP is small, elongated and smooth. The P-E transition presents a first distal and a second median ER while both the PP and ELP originates from a third proximal ER. The epiphallar formula is: 1ER+2ER+3ER(PP+ELP). The E shows five to seven smooth longitudinal pleats that proximally turn into a pattern of coarse small weak pleats that gradually fade away towards the VD. The V shows a set of heavy and robust transverse smooth pleats that proximally begin somehow irregularly. The wall is smooth.

Comparative analysis.

Siciliaria tiberii armettensis ssp. nov., like the nominate subspecies, has a ribbed shell and it is clearly distinguishable from all the remaining subspecies that present a more or less striated but ribless shell surface. Nonetheless, the nominate subspecies shows a stronger ribbing, with elevated and robust ribs. The distal end of the AUPP always presents a knob that is well visible from the frontal view (Figs 28 .1-28.2). This feature is shared also by the nominate subspecies (Fig. 26 .1) but only by the ≈25% of the investigated specimens (n = 40).

Ecology.

Siciliaria tiberii armettensis ssp. nov. inhabits east-exposed limestone walls and cliffs, hiding among tuft of vegetation, rocks cracks and crevices.

Distribution.

Siciliaria tiberii armettensis ssp. nov. is exclusively known from the type locality, the surroundings of the Grotta dei Puntali o dell’Armetta. Further field investigation along the Monte Pecoraro eastern slopes is needed in order to determine the actual distribution of the taxon. Grotta dei Puntali o dell’Armetta are included in the protected area Riserva Naturale Grotta dei Puntali.

Etymology.

The taxon is named after the Grotte dell’Armetta, a complex of natural caves where wall engravings and stone handcrafted tools, dated from the Paleolithic to the Bronze Age, were discovered ( Mannino 1978).

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 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.

Figure 27. Siciliaria tiberii armettensis ssp. nov., Grotta dei Puntali, Carini 27.1 whole distal genital organs 27.2 internal distal part of genital organs 27.3 detail of the pseudopapilla. Siciliaria tiberii scalettensis Beckmann, 2004 Portella Scaletta, Villagrazia 27.4 whole distal genital organs 27.5 internal distal part of genital organs 27.6 detail of the pseudopapilla.

Figure 28. Siciliaria tiberii armettensis ssp. nov., Grotta dei Puntali, Carini 28.1 shell 28.2 shell clausiliar plate double side 28.3 detail of the aperture 28.4 clausiliar plate double side. Siciliaria tiberii scalettensis Beckmann, 2004 Portella Scaletta, Villagrazia 28.5 shell 28.6 detail of the aperture 28.7 shell 28.8 detail of the aperture 28.9 clausiliar plate double side.