Sicania nobilis spezialensis (Nordsieck, 1984), stat. nov., 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

Sicania nobilis spezialensis (Nordsieck, 1984), stat. nov. comb. nov.

Figs 1.F, 35.1-35.7, 36.14-36.16

Siciliaria (Siciliaria) spezialensis Nordsieck 1984: 202.

Siciliaria (Siciliaria) spezialensis - Manganelli et al. 1995: 25.

Charpentieria spezialensis - Beckmann 2004: 188.

Siciliaria spezialensis - Welter-Schultes 2012: 343.

Siciliaria spezialensis - Nordsieck 2013b: 9.

Charpentieria spezialensis - De Mattia 2017j.

Specimens examined.

Italy, Sicily, San Vito Lo Capo, Macari, E side of Monte Speziale , 75 m asl, 38°07'41.78"N, 12°44'9.24"E, [Lab ID 63_1, COI: MW758910 , ITS2: MW757039, MW757040 ; Lab ID 63_2, COI: MW758911 ], W. De Mattia and J. Macor leg., 14.iv.2017. 4 dissected spm .

Shell

(Figs 36 .14-36.16). Shell decollate; whorls densely ribbed, without or with very weak sutural papillae; dorsal keel absent; inferior lamella moderately high; anterior upper palatal plica absent, posterior upper palatal plica very short; ALPP very short to knob-like, posterior lower reduced; palatal edge of clausilium plate distally not receding, palatal edge distally not bent upwards (see Nordsieck, 1984: 202).

Measurements

(n = 24, decollate). shell height 22.2 ± 1.3, whorl width 5.1 ± 0.2, aperture height 4.1 ± 0.3, aperture width 2.8 ± 0.3.

External morphology of the genital organs

(Figs 35 .1, 35.3). The FO is longer than the V (FO/V range 1.9-2.2). The VD is thin along its whole course. The FDBC is slightly longer than the BC+SDBC (FDBC/BC+SDBC range 1.1-1.2). The BC+SDBC is club-like and longer than the V (BC+SDBC/V range 1.7-1.8), with no clear distinction between the SDBC and the BC. The apex is big and rounded. The D is longer than the V (D/V range 2.1-2.3) and longer that the BC+SDBC (D/BC+SDBC range 1.3-1.7), thinner than the BC+SDBC and with a small and round apex. The V is cylindrical. The A is very large. The PC is longer than the V (P+E/V range 1.8-2.0). The PR is short and robust. The E is almost as long as the P (E/P range 0.8-0.9), gradually shrinking and turning into the VD.

Internal morphology of the genital organs

(Figs 35 .2, 35.4-35.7). The V distally presents a set of irregular, weak, and fleshy folds that proximally become a set of oblique smooth pleats. The A shows a set of irregular fleshy folds. The P presents 4-to 6 longitudinal fleshy smooth pleats, slightly depressed in the middle forming a sort of longitudinal hollow. These pleats distally become weak and irregular entering in the A. The fine structure of the wall is smooth. The PP is little, rhombus-shaped and smooth. The P-E transition presents a first distal ER, whereas the PP and the ELP originate from the second proximal ER. The epiphallar formula is: 1ER+2ER(PP+ELP). The E shows a pattern of three or four irregular longitudinal fringed pleats. The wall of the E is smooth.

Ecology.

Sicania nobilis spezialensis stat. nov., comb. nov. is a strictly limestone dweller and inhabits cliffs, hiding among rock cracks and crevices. As previously deemed as a species, according to De Mattia (2017j) the taxon is Critically Endangered.

Distribution.

Sicania nobilis spezialensis stat. nov., comb. nov. is known only from the type locality: along the western cliffs of Monte Speziale in the surroundings of Macari (San Vito lo Capo). No overlapping zone with Sicania nobilis nobilis stat. nov., comb. nov. is known until now. Although, in its original description, the taxon was reported for one locality only ( Nordsieck 1984: 202 "Monte Speziale bei San Vito"), the same author reported later and extended area of distribution ( Nordsieck 2013b: "from Macari and Castelluzzo to Monte Speziale and Monte Acci").

Remarks.

Sicania nobilis spezialensis stat. nov., comb. nov. is now considered as a subspecies of S. nobilis . It is well embedded within the clade of Sicania nobilis in both COI and combined trees. Sicania nobilis spezialensis stat. nov., comb. nov. is a local isolated, spatially restricted ribbed form of the more widespread Sicania nobilis comb. nov. with few different features of the shell, viz. the lack of the anterior upper palatal plica and a clausilium plate that fits into a frame of the palatal plicae.

Mauritanica taxonomic part

The genus Mauritanica comprises four species that are distributed over northeastern Algeria and central-northern Tunisia ( Nordsieck 2002; Sparacio et al. 2020). It is currently considered as a subgenus of Charpentieria (MolluscaBase 2021). Only the Tunisian taxa were recently reviewed ( Sparacio et al. 2020), mainly by means of shell morphology and a brief analysis of the anatomy of the genital organs, discussing the position of the genus and separating it from Charpentieria without involving additional morphological and molecular genetic data.

In our molecular genetic analysis (Figs 4 - 6 ) we only had Mauritanica perinni polygyra available. In the COI, ITS2 and combined trees, this species falls outside the Siciliaria / Sicania clades, forming a separate independent clade together with Siciliaria scarificata , endemic to Marettimo. In the COI tree, this clade represents the “sister” clade of Sicania (average p distance 17%) and the same is found in the ITS2 tree (Fig. 5 ), yet with lower support. Despite low sample number, no association with any of the other Charpentieria lineages was observed.

The separation of Mauritanica from Siciliaria / Sicania is consistent through all the trees, thus we provisionally keep Mauritanica as a distinct genus, although the type species Mauritanica tristrami (L. Pfeiffer,1861) was not available to us. In order to fully understand the phylogenetic relationships of Mauritanica with Siciliaria / Sicania more genetic markers and specimens are essential.

Both M. perinni polygyra and M. scarificata underwent anatomical investigation. A similar external genital morphology was detected. The only noticeable difference is the relative length of the FO, with a V/FO ratio of 1.1 for M. scarificata and 0.6 for M. perinni polygyra . Remarkable differences were detected regarding the internal details of the penial complex. Mauritanica scarificata presents 3 ERs with a very short and globose PP that makes it fall into the general Siciliaria / Sicania genital anatomical arrangement. Mauritanica perinni polygyra lacks any ER and the PP is irregular with a convolute surface pattern. It is directly connected to the OELP. Unfortunately, the genital descriptions and the pictures provided by Sparacio et al. (2020) do not include fine details of the internal genital organs (ER, PP structure and origin, ELP etc) so that any comparison to our results is impossible.

Following our genital anatomical investigations, the common genital anatomical traits deemed by Nordsieck (2013a, 2013b) to justify his proposal to consider Mauritanica as a subgenus of Siciliaria , namely, "the presence of a thickening in the passage from the penis to the epiphallus and the indistinct delimitation between proximal and distal penis" revealed that it is probably not a reliable feature. The thickening was not found in Mauritanica perinni polygyra (Fig. 37 ). Moreover, the delimitation between proximal and distal penis revealed to be an extremely subtle and variable character also in Siciliaria , Charpentieria and Stigmatica . Only few taxa of Charpentieria show a detectable, constant and distinct delimitation between proximal and distal penis [e.g., Charpentieria itala lorinae (Fig. 46 .7) and Charpentieria itala trepida (Fig. 49 .1)].

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 4. BI tree of based on the COI data set of Siciliaria, Sicania and related genera. BI posterior probability values (> 0.90) of major nodes are indicated.

Figure 5. BI tree of based on the ITS 2 data set of Siciliaria, Sicania and related genera. Colours of Siciliaria and Sicania clades correspond to those in the distribution maps (Figs 1 E, F). BI posterior probability values (> 0.90) of major nodes are indicated.

Figure 6. BI tree of based on the concatenated COI and ITS 2 data set of Siciliaria, Sicania and related genera. Colours of Siciliaria and Sicania clades correspond to those in the distribution maps (Fig. 1 E, F). BI posterior probability values (> 0.90) of major nodes are indicated.

Figure 36. Sicania nobilis nobilis (A. Schmidt, 1868), comb. nov., Castelluzzo 36.1 shell 36.2 detail of the aperture 36.3 clausiliar plate double side. San Vito Lo capo, camping 36.4 shell 36.5 detail of the aperture 36.6 clausiliar plate double side. San Vito Lo Capo, boulders 36.7 shell 36.8 detail of the aperture 36.9 clausiliar plate double side. Torre delle Usciere (ex. forma Sicania nobilis nobilis episoma) 36.10 shell 36.11 detail of the aperture 36.12 clausiliar plate double side. Monte Cofano, Tonnara Cofano 36.13 shell. Sicania nobilis spezialensis (Nordsieck 1984), stat. nov., comb. nov. Macari 36.14 shell 36.15 detail of the aperture 36.16 clausiliar plate double side.

Figure 37. Mauritanica scarificata (L. Pfeiffer, 1856), comb. nov., Marettimo 37.1 whole distal genital organs 37.2 internal distal part of genital organs 37.3 whole distal genital organs 37.4 internal distal part of genital organs 37.5 detail of the pseudopapilla. Mauritanica perinni polygyra (O. Boettger, 1879), Tunisia, Zaghouan 37.6 whole distal genital organs 37.7 internal distal part of genital organs 37.8 - 37.9 spermatophore 37.10 cross section of the spermatophore.

Figure 46. Charpentieria itala clavata (Rossmaessler, 1836), Ballabio, Lecco 46.1 whole distal genital organs 46.2 internal distal part of genital organs 46.3 cross section of the pseudopapilla 46.3 spermatophore. Charpentieria itala latestriata (Kuester, 1850), Bedulita, Bergamo 46.5 whole distal genital organs 46.6 internal distal part of genital organs. Charpentieria itala lorinae (Gredler, 1869), Val Lorina, Storo 46.7 whole distal genital organs 46.8 internal distal part of genital organs.

Figure 49. Charpentieria itala triumplinae Nardi, 2011, Lavenone, Brescia 49.1 whole distal genital organs 49.2 internal distal part of genital organs. Charpentieria itala variscoi (Pini, 1883), Val Taleggio, Bergamo 49.3 whole distal genital organs 49.4 internal distal part of genital organs.

Figure. 35. Sicania nobilis spezialensis (Nordsieck 1984), stat. nov., comb. nov. Macari 35.1 whole distal genital organs 35.2 internal distal part of genital organs 35.3 whole distal genital organs. 35.4 internal distal part of genital organs 35.5 cross section of the pseudopapilla 35.6 cross section of the epiphallus 35.7 detail of the pseudopapilla.