Siciliaria grohmanniana addaurae, 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 grohmanniana addaurae ssp. nov.

Figs 1.F, 7.4-7.6, 8.5-8.9, 13.5-13.8

Type locality.

Italy, Sicily, Palermo, N side of Monte Pellegrino, Punta Priola, Grotte dell’Addaura, 115 m asl, 38°11'13.01"N, 13°21'6.91"E.

Type material.

1 Holotype (NHMW 113611) [Lab ID 41_1, COI: MW758883, ITS2: MW757093, MW757094] and 8 Paratypes (NHMW 113612): Italy, Sicily, Palermo, N side of Monte Pellegrino, Punta Priola, Grotte dell’Addaura, 115 m asl, 38°11'13.01"N, 13°21'6.91"E, [Lab ID 41_2, COI: MW758884; Lab ID 41_3 COI: MW758929], W. De Mattia and J. Macor leg., 15.iv.2017. 3 dissected spm. 10 Paratypes (CWDM 18222): same locality.

Shell diagnosis.

Shell decollate; whorls ribbed; dorsal keel weak but distinguishable; inferior lamella very high; two anterior upper palatal plicae present, both of them separated from the lunella; parietalis short ends before the beginning of the spiralis; palatal edge of clausilium plate distally receding, plate gutter-like narrowed, palatal edge against distal end bent upwards and more or less pointed.

Shell description (Figs 8 .5-8.9, 13.5-13.8).

The shell is elongated, fusiform, sinistral and decollate, rarely not decollate. It is brown to reddish brown in colour. The external surface has small raised ribs almost equally arranged in all whorls of the teleoconch. The spire slowly and regularly grows with eight or nine whorls that are only slightly convex. The sutures are moderately shallow with very rare whitish papillae present towards the apex. The basal and the cervical keels are weak but distinguishable. The umbilicus is closed. The aperture width is ~ 1⁄4 of shell height and subovoid in shape. The PRI is long and raised, wider along its posterior part and not fused with the L. The PRI is not visible from the aperture. The L is antero-lateral, with a reduced, knob-like PUPP connected to it. There are two AUPP, both of them detached from the L and barely visible from the aperture. The upper AUPP is stronger and longer than the lower one. The ALPP (BAS) starts directly from the L and it is long and strong, clearly visible from the aperture. The SCL is present and robust. It is connected to the L. The IL is high to very high. The SUL is short, tooth-like and ends before the beginning of the SPL that is wider along its posterior part. The SCOL is not emergent. 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 narrow and gutter-like.

Measurements

Holotype: decollate shell height 17.3, whorl width 4.5, aperture height 4, aperture width 2.5. Paratypes (n = 20, decollate): shell height 17.2 ± 0.6, whorl width 4.4 ± 0.1, aperture height 3.9 ± 0.3, aperture width 2.9 ± 0.3.

External morphology of the genital organs (Fig. 7 .4).

The FO is longer than the V (FO/V range 1.5-1.7). The VD is thin along its whole course. The FDBC is longer than the BC+SDBC (FDBC/BC+SDBC range 1.0-1.3). The BC+SDBC is cylindrical or club-like and slightly longer than the V (BC+SDBC/V = 1.1), with no clear distinction between the SDBC and the BC. The apex is wide and round. The D is longer than the V (D/V range 1.3-1.5) and longer that the BC+SDBC (D/BC+SDBC range 1.1-1.3), thinner than the BC+SDBC and with a small apex. The V is long and cylindrical and thin in diameter. The A is small. The PC is longer than the V (P+E/V range 1.6-1.8). The PR is long and thin. There is a clear distinction between P and E as there is a visible ER and a proximal narrowing. The E is much thinner but longer than the P (E/P range 1.2-1.5), gradually shrinking and turning into the vas deferens.

Internal morphology of the genital organs (Figs 7 .5, 7.6).

The A is smooth. The P presents very smooth and scarcely elevated weak transverse pleats. The fine structure of the wall is smooth. The PP is big, rounded and smooth. It originates from the big epiphallar ring. The P-E transition presents one ER with the PP originating from it. The ELP are not connected with the ER. The epiphallar formula is: 1ER(PP)+ELP. The E shows three or four main smooth longitudinal pleats. The proximal V shows an irregular set of smooth longitudinal pleats that, distally, turn into a smooth fold that goes as far as the atrium.

Comparative analysis.

Siciliaria grohmanniana addaurae ssp. nov. differs from Siciliaria grohmanniana grohmanniana by its slender shape and darker shell colour and its denser ribbing (Fig. 8 .5, 8.6). The two AUPP are longer and stronger. The basal and the cervical keels are more prominent. The internal wall of the P presents different sculpturing: smooth and scarcely elevated weak transverse pleats versus 4 to 6 longitudinal and very irregular pleats (Fig. 7 .5). Siciliaria grohmanniana addaurae ssp. nov. differs from Siciliaria septemplicata by its more ribbed surface and the stronger ALPP. The SCL is much longer and more robust. The internal wall of the P presents different sculpturing: smooth and scarcely elevated weak transverse wrinkles versus four to five smooth longitudinal or fringed pleats. (Fig. 7 .5).

Distribution.

Siciliaria grohmanniana addaurae ssp. nov. is exclusively known from the type locality, along the limestone cliffs around the Addaura caves near Punta Priola, Palermo. It is likely to be present in other spots along the northeastern limestone cliffs of the Monte Pellegrino, but more research is needed to define its distribution.

Ecology.

Siciliaria grohmanniana addaurae ssp. nov. is an obligate rock-dweller and inhabits the limestone cliffs, on open walls or hiding in cracks in humid spots, around the Addaura caves. This subspecies has a very limited distribution range with an area of much less than 1 km2. Although, the area is included in the Riserva Naturale Orientata Monte Pellegrino and the Addaura caves are fenced, the habitat quality is inferred to be declining due to no access regulation nor restriction, resulting in dumping, littering and murals on the limestone walls ( Ferrante 2011).

Etymology.

The taxon is named after the Addaura caves, a complex of three natural caverns where wall engravings dated to the Paleolithic and the Mesolithic were discovered.

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 7. Siciliaria grohmanniana grohmanniana (Rossmaessler, 1836), Monte Pellegrino, Palermo 7.1 whole distal genital organs 7.2 internal distal part of genital organs 7.3 penial pseudopapilla detail. Siciliaria grohmanniana addaurae ssp. nov. Grotta dell'Addaura, Punta Priola 7.4 whole distal genital organs 7.5 internal distal part of genital organs 7.6 penial pseudopapilla detail.

Figure 8. Siciliaria grohmanniana grohmanniana (Rossmaessler, 1836), Monte Pellegrino, Palermo 8.1 shell 8.2 shell 8.3 detail of the aperture 8.4 clausiliar plate double side. Siciliaria grohmanniana addaurae ssp. nov. Grotta dell'Addaura, Punta Priola 8.5 shell 8.6 shell 8.7 detail of the aperture 8.8 detail of the columellar side of last whorl 8.9 clausiliar plate double side.