Mauritanica perinni polygyra (O. Boettger, 1879)

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

Mauritanica perinni polygyra (O. Boettger, 1879)

Figs 37.6-37.10, 38.5, 38.6

Clausilia (Mauritanica) polygyra Boettger in Kobelt 1879: 153.

Charpenteria (Mauritanica) perinni polygyra - Nordsieck 2002: 27, 29, 35, 36.

Charpenteria (Mauritanica) perinni polygyra - Nordsieck 2007: 54.

Mauritanica perinni polygyra - Sparacio et al. 2020: 318.

Remarks.

Mauritanica perinni polygyra was recently revised by Sparacio et al. (2020: 318). Based on differences of the shell morphology alone, Sparacio et al. (2020: 319) proposed species status for Mauritanica perinni polygyra , independent from Mauritanica perinni perinni (Bourguignat, 1876). A genital comparison with the nominate subspecies was not possible since the genital organs of this taxon were not provided by Sparacio et al. (2020). Moreover, a comparison between our anatomical results and those provided by Sparacio et al. (2020: 337, figs 60-61) for Mauritanica perinni polygyra was rather difficult: Essential details, as the internal structure of the epiphallus and the presence/absence of the ER and ELP are not detectable. The fine structure of the internal penis is not clear and, contrary to our results that show a smooth internal wall, the vagina seems to have a smooth longitudinal pleat (2020: 337, fig. 61). The presence of the ET is not clear as well (2020: 337, fig. 60).

Specimens examined.

Tunisia, above Zaghouan (road to summit), 789 m asl, 36°22'2.45"N, 10°07'11.81"E, [Lab ID SMF335011_1, COI: MW758966 , ITS2: MW757044, MW757045 ], ex Nordsieck coll. (11639), currently SMF 335011/1, 1 dissected spm .

Shell

(Figs 38 .5, 38.6). Shell decollate or not decollate; whorls finely and irregularly striated, flat, with dense papillae along the sutures; dorsal keel indistinct; inferior lamella high; anterior upper palatal plicae absent; posterior upper palatal plica present; lunella dorso-lateral; little subclaustralis, clausilium plough-like with subrectangular plate ( Sparacio et al. 2020: 318).

Measurements

(n = 1, decollate). shell height 22.4, whorl width 4.1, aperture height 3.3, aperture width 2.4.

External morphology of the genital organs

(Fig. 37 .6). The FO is longer than the V (FO/V = 2.1). The VD is thin along its whole course. The FDBC is slightly shorter than the BC+SDBC (FDBC/BC+SDBC = 0.9). The BC+SDBC is club-like and longer than the V (BC+SDBC/V = 1.4), with clear distinction between the SDBC and the BC. The SDBC is very short. The apex is big and round. The D is much longer than the V (D/V = 1.9) and longer that the BC+SDBC (D/BC+SDBC = 2.2), thinner than the BC+SDBC and with a small and round apex. The V is cylindrical but the presence of the spermatophore may modify its normal shape. The A is small. The PC is longer than the V (P+E/V = 2.8). The PR is long and robust. The ET is not clearly visible. The E is shorter than the P (E/P = 0.9), gradually shrinking and turning into the VD.

Internal morphology of the genital organs

(Fig. 37 .7). The A, V and the P show a very finely granulated surface. The PP is small, elongated. Its surface is very irregular, folded and its internal texture is spongy. The P-E transition is simple, with no ER. The origin of the PP is connected with one of the two ELP. The epiphallar formula is: PP(ELP). The E shows two smooth longitudinal pleats that fade before the VD. Between the ELP an irregular transverse small, interrupted pattern gives an overall coarse appearance.

Spermatophore

(Figs 37 .8-37.10). The spermatophore is thin, elongated. It is 4.7 mm long and 0.8 mm wide at its widest point. The tail is pointed and sharp. The head is missing, probably already digested. The upper keel is simple and goes from the tip of the tail as far as the broken head part. The lower keel is missing.

Ecology.

Mauritanica perinni polygyra is a limestone dweller, on cliffs, crevices and under stones ( Sparacio et al. 2020: 319).

Distribution.

Mauritanica perinni polygyra is known only from Djebel Zaghouan area ( Sparacio et al. 2020: 319).

An overview of Siciliaria related genera Charpentieria , Gibbularia , and Stigmatica

The separation of Siciliaria and Sicania (and provisionally Mauritanica ) from the other genera is well supported, but the relationships among Charpentieria , Stigmatica and Gibbularia remain unresolved and appear as polytomy in the trees. Charpentieria (four species included) forms one (poorly supported) clade but, the relationships within this clade received no considerable support. The genera Stigmatica and Gibbularia are not monophyletic and populations from distant areas show high genetic distances (Table 2 ). Stigmatica is based on Clausilia stigmatica by tautonomy and, in our trees (Figs 4 - 6 ), only this clade with the type species Stigmatica stigmatica can be deemed as a representative of this genus. Despite emerging from a polytomy, additional taxa included in our trees and currently considered as belonging to Stigmatica (namely Stigmatica vulcanica and Stigmatica pantocratoris ) are clearly separated from the type species. We thus only conventionally keep them as Stigmatica species. A focused approach with more genetic markers and specimens is needed to identify the phylogenetic relationships among the species currently included into Stigmatica (following MolluscaBase 2021). A similar approach is used for Gibbularia , which needs to be excluded from Siciliaria / Sicania (Figs 4 - 6 ). Its phylogenetic relationship with the other genera is far from being resolved.

Papillifera , which was used as outgroup, appeared monophyletic in our trees, even though the distances within this genus are in the same range as among different genera.

Southern alpine Charpentieria

The taxa included in the alpine Charpentieria itala - Charpentieria ornata - Charpentieria dyodon clade show a pan-Southern Alpine distribution, with C. dyodon isolated in Piemonte and Ticino, C. itala along central and eastern Southern Alps whereas C. ornata is present along the easternmost Southern Alps and northwestern Balkans. The taxa included in the C. stenzii subclade occupy the eastern Southern Alps, from eastern Trentino-Alto Adige, Friuli-Venezia Giulia, W Slovenia and SE Austria.

Despite the low support values, the COI and the ITS2 phylogenetic trees (Figs 4 , 5 ) show a general picture where Charpentieria dyodon dyodon (S. Studer, 1820) appears as the sister species of Charpentieria itala (with C. itala itala , C. itala baldensis and C. itala lorinae ). Charpentieria stenzii (with C. stenzii cincta and C. stenzii letochana ) represents a separate clade.

The results presented by Scheel and Hausdorf (2012: 3799, 3801) and Xu and Hausdorf (2021: 8) showed that C. dyodon is the sister species of the C. itala complex whereas C. stenzii is sister to C. ornata . These results are difficult to compare with our trees, but at least not in contrast.

The stenzioid subspecies of C. itala included in our genital anatomical investigations ( Charpentieria clavata , Charpentieria variscoi , Charpentieria balsamoi , and Charpentieria lorinae ) were first assigned to C. stenzii ( Käufel, 1928) but later transferred to C. itala by Nordsieck (1963a, b). In 2007, Nordsieck (2007) transferred these taxa to C. clavata . Scheel and Hausdorf (2012), following their molecular genetic results considered the stenzioid C. clavata as subspecies of C. itala , and thus, its subspecies obtained a new combination with C. itala . Scheel and Hausdorf (2012: fig. 3) and Xu and Hausdorf (2021: 6, fig. 5, supplementary table S1) revealed gene flow between C. stenzii and the stenzioid subspecies of C. itala across the contact zone and also highlighted several mixture events within the C. itala complex.

The list of the dissected material (at least two specimens per population) is found in the Table 8 .

The present anatomical investigation indeed generated consistent results that are congruent with the molecular genetic outcomes.

Charpentieria itala - Charpentieria ornata - Charpentieria dyodon and C. stenzii groups of taxa show the same external overall shape of the distal genital organs (Figs 40 , 41 , 43 - 46 , 48 , 49 , 51 - 55 ). No major difference can be observed regarding the main genital parts as, e.g., the shape and relative dimensions of the OSD, FO, A and penial complex (P+E). Only the V is shorter in C. stenzii , with an average P/V ratio of 1.4 for C. itala and 2.3 for C. stenzii . Moreover, this general external genital arrangement of Charpentieria is not distinguishable by any means from Siciliaria , Sicania , and Mauritanica .

The genus Charpentieria was introduced by Stabile (1864: 80) [type species: Charpentieria dyodon (S. Studer, 1820)]. The type species was subsequently designated by Kennard and Woodward (1923: 306). Boettger (1877: 53) listed only C. dyodon and its subspecies for the genus Charpentieria .

Boettger (1877: 35) introduced the name Tirolica as "Gruppe der Stentzi " (type species: Delima stenzii = Charpentieria Charpentieria stenzii ), that included most of the stenzioid southern alpine taxa known in 1877. This genus included taxa currently belonging to both Charpentieria itala ( C. i. balsamoi and C. i. lorinae ) and C. stenzii ( C. s. stenzii and its synonym Clausilia saccata Küster, 1848, C. stenzii cincta and its synonyms: Clausilia rossmaessleri L. Pfeiffer, 1841, Clausilia cincta var. maior Rossmässler, 1842 and Clausilia cincta var. minor Westerlund, 1878 and finally C. s. letochana and its synonym Clausilia funki Gredler, 1874). Inexpicably, Boettger (1877:35) did not include the stenzioid C. stenzii paroliniana (De Betta & Martinati, 1855) and C. itala clavata . Xu and Hausdorf (2021: 6), after sequencing 843 loci, found that C. stenzii is well embedded in Charpentieria . Although our anatomical investigations revealed a peculiar internal structure of the P-E transition and the penial pseudopapilla is found exclusively in C. stenzii (we named it hemipapilla, see point 6.6 for a detailed decription), we follow Xu and Hausdorf (2021) in not separating this group on generic level. The hemipapilla was not found in the stenzioid subspecies despite the notable gene flow with C. stenzii , as proven by Xu and Hausdorf (2021: 7).

Boettger, 1877, introduced the genus Itala as "Gruppe der Itala itala " (type species: Delima itala = Charpentieria Charpentieria itala ), including all the alpine non-stenzioid taxa, excluding C. dyodon but including two stenzioid taxa: C. stenzii paroliniana and C. itala clavata . He also included two taxa from the Balkans: Delima conspersa [= Strigilodelima conspersa (L. Pfeiffer, 1848)] and its synonym Delima platystoma Küster, 1850. As for Tirolica , the recent results by Xu and Hausdorf (2021: 6-8) indicated that the Charpentieria itala complex should not be separated on a (sub)generic level (i.e., Itala ).

Wagner (1925: 17) introduced the genus subgenus Clausilia Alpidelima [type species Clausilia itala Martens, 1824, by subsequent designation by Schileyko (2000: 664)] that must be deemed as a junior synonym of Charpentieria .

Nordsieck (1963a: 95, figs 9-10; 97, fig. 11; 1963b: 185, 189, 193, 197) depicted the genital organs of some taxa currently belonging to the genus Charpentieria from the Alps. The sketchy drawings lacked important details, both concerning internal and external features. Except for fig. 11a of Nordsieck (1963a), the exact position of the insertion of the proximal vas deferens into the beginning of the free oviduct was not clear. The internal structure of the penis-epiphallus transition was not investigated. The pseudopapilla was shown, but its origin was missing as well as its connection to (and the presence/absence of) the epiphallar ring(s) and the epiphallar longitudinal pleats. Only in Nordsieck (1963a: fig. 11b) the origin of the pseudopapilla and the epiphallar ring seem to be roughly depicted. Nordsieck (1963a) reported the presence of the penial flagellum for all the four taxa, which is in contrast to our results, based on 63 specimens, where this particular anatomical structure was never detected despite careful check.

He introduced a new subspecific taxon, C. itala serravalensis (1963a: 175), but depicted its external anatomy of the genital organs [Nordsieck, 1963b: 184-185, Abb. 47 Charpentieria itala Charpentieria serravalensis , Serravalle ( präp. 109)] with the same genital drawing provided for C. itala itala in Nordsieck, (1963a: 97, fig. 11a, b). The shell description, genital organs and measures provided for C. itala serravalensis ( Nordsieck 1963b: 175) match with the morphology of the specimens from Colli Euganei (San Donato, Barbarano Vicentino, Padova, Italy) (Fig. 44 .1-44.4) studied in the present paper.

Nordsieck cites C. itala itala (1963a) but unexpectedly, Nordsieck (1963b) neither cited the nominate subspecies, nor did he provide information about the type locality of the species

Charpentieria itala was described by G. von Martens (1824: 442), but he did not provide any indication about the collecting site. L. Pfeiffer (1853: 606) reports the description of the species given by Martens. In his "Reisebemerkungen über einige Binnenschnecken Italiens", E. von Martens (1857: 129), the son of G. von Martens, finally gives precise indications where his father collected the first series of specimens of C. itala (between Mira and Dolo): "Zwischen Mira und Dolo hatte mein Vater auch früher seine Clausilia itala .". Dolo and Mira are located in the province of Venice, between Venice and Padova, along the river Brenta in the Pianura Padana. Being it a quaternary alluvial plain area, the specimens were probably collected on walls and houses. Eduard von Martens (1857: 129) collected more samples of C. itala from the walls of the Botanic Garden of Padova. These alluvial plain populations probably originate from downstream transport by creeks, deriving from the Colli Euganei and Colli Berici, which flow into the Brenta River.

Brief genital anatomical description of Charpentieria dyodon subspecific taxa: the parapseudopapilla

Charpentieria dyodon is the name-bearing species of the genus Charpentieria . It comprises five subspecies [ C. dyodon dyodon (Studer, 1820; C. dyodon alpina (Stabile, 1859); C. dyodon paulucciana (Pollonera, 1885); C. dyodon studeri (Pini, 1885) and C. dyodon thomasiana ( Küster, 1850)]. These taxa are distributed over an area that includes the western Southern Alps of Piemonte, Italy (from Dora Riparia River to Lago Maggiore) and the South Switzerland (Ticino and Valais). This species is not sympatric with any other Charpentieria species.

In our COI tree only the nominate subspecies Charpentieria d. dyodon was included (Figs 4 - 6 ). It emerged as the sister species of C. itala , yet with only low node support.

Three out of five subspecies of C. dyodon were anatomically investigated (Table 8 ). They revealed a common overall genital arrangement (Figs 40 , 41 ), including a stable presence of the penial pseudopapilla. The pseudopapilla can be either simple or rooted. The internal wall of the penis is smooth, the epiphallus shows two fringed longitudinal pleats and the internal wall of V presents many smooth longitudinal pleats. Charpentieria dyodon has a distribution detached from C. itala with no overlapping areas. Charpentieria dyodon shows substantial differences of the shell characters (smooth or weakly striated surface, lunella mostly absent and no palatal folds, sutural papillae very scarce or absent) and epiphallar structure (see the following chapter).

The four populations of Charpentieria dyodon included for dissection, revealed a very stable morphology of the genital organs (Figs 40 , 41 ). The internal surface of the P is smooth and the V presents many smooth longitudinal pleats that stop before entering the atrium. The external transition between P and E is always visible. Charpentieria dyodon revealed a peculiar morphology of the pseudopapilla and the internal transition area between penis and epiphallus (Figs 40 , 41 ). The parapseudopapilla involves the pseudopapilla and the epiphallar longitudinal pleats: the pseudopapilla has its origin at the distal end of one epiphallar longitudinal pleat ( “occupied“ epiphallar longitudinal pleat) and the opposite wall is delimited and narrowed by the other epiphallar longitudinal pleat ( “free“ epiphallar longitudinal pleat) and connected by a ER, creating a funnel-like structure. The PPP, at a first glance, resembles a true penial papilla, but it remarkably lacks the seminal channel. The extremely large ER of the PPP completely obstructs the lumen of the transition area. The connection between the penis and epiphallus is represented by a short, narrow passage, named "epiphallar funnel" (EF), that is found at the base of the PPP and it is quite difficult to detect.

This parapseudopapilla represents an intermediate form between the simple structure of Charpentieria itala and the hemipapilla (HP) of Charpentieria stenzii . In the normal PP the transition stretch E is relatively wide and the counter wall opposite of the PP is represented by the simple P-E transition wall.

Figures

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 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 38. Mauritanica scarificata (L. Pfeiffer, 1856), comb. nov., Marettimo 38.1 shell 38.2 shell 38.3 detail of the aperture 38.4 clausiliar plate double side. Mauritanica perinni polygyra (O. Boettger, 1879), Tunisia, Zaghouan 38.5 shell 38.6 shell (picture courtesy of Claude and Amandine Evanno).

Figure 40. Charpentieria dyodon dyodon (S. Studer, 1820), Verbano 40.1 whole distal genital organs 40.2 internal distal part of genital organs. Charpentieria dyodon alpina (Stabile, 1859). Val di Lanzo, Usseglio 40.3 whole distal genital organs 40.4 internal distal part of genital organs.

Figure 41. Charpentieria dyodon thomasiana (Kuester, 1850), Piedicavallo 41.1 whole distal genital organs 41.2 internal distal part of genital organs. Oropa, Biella 41.3 whole distal genital organs 41.4 internal distal part of genital organs.

Figure 43. Charpentieria ornata (Rossmaessler, 1836), Ogulin, HR 43.1 whole distal genital organs 43.2 internal distal part of genital organs.

Figure 44. Charpentieria itala itala (G. von Martens, 1824), Barbarano Vicentino 44.1, 44.2 whole distal genital organs 44.3 internal distal part of genital organs 44.4 detail of the pseudopapilla. Charpentieria itala albopustolata (De Cristofori & Jan, 1832), Brescia 44.5 whole distal genital organs 44.6 internal distal part of genital organs. Charpentieria itala allatollae (Kaeufel, 1928), Val Ampola, Storo 44.7 whole distal genital organs 44.8 internal distal part of genital organs.

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 48. Charpentieria itala zalloti nom. nov., Udine 48.1 whole distal genital organs 48.2 internal distal part of genital organs. Charpentieria itala serravalensis (Nordsieck, 1963), Serravalle, Vittorio Veneto 48.3 whole distal genital organs 48.4 internal distal part of genital organs. Charpentieria itala trepida (Kaeufel, 1928), Cima Ora, Anfo 48.5 whole distal genital organs 48.6 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 51. Charpentieria stenzii stenzii (Rossmaessler, 1836), San Romedio, Trento 51.1 whole distal genital organs 51.2 internal distal part of genital organs 51.3 cross section of the epiphallus. Charpentieria stenzii butoti (Bank, 1987), Fai della Paganella 51.4 whole distal genital organs 51.5. internal distal part of genital organs 51.6 detail of the hemipapilla: uncut 51.7 detail of the hemipapilla: cut funnel 51.8 cross section of the epiphallus.

Figure 55. Charpentieria stenzii nordsiecki Fauer, 1991, Cison di Valmarino, Treviso 55.1 whole distal genital organs 55.2 internal distal part of genital organs. Charpentieria stenzii paroliniana (De Betta & Martinati, 1855), Valstagna, Vicenza 55.3 whole distal genital organs 55.4 detail of the hemipapilla: uncut 55.5 internal distal part of genital organs with cut funnel. Charpentieria stenzii westerlundi Nordsieck, 1993, Val Fiscalina, Bolzano 55.6 whole distal genital organs 55.7 internal distal part of genital organs with cut funnel.