Siciliaria calcarae jatinensis, 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 calcarae jatinensis ssp. nov.

Figs 1.F, 18.3-18.7, 19.6-19.8, 24.7-24.8

Type locality.

Italy, Sicily, San Giuseppe Jato, quarry E of the town, 630 m asl, 37°58'15.07"N, 13°12'2.23"E.

Type material.

1 Holotype (NHMW 113615) [Lab ID 34_2, COI: MW758879, ITS2: MW757118, MW757119, MW757120, MW757121] and 5 Paratypes (NHMW 113616): Italy, Sicily, San Giuseppe Jato, quarry E of the town, 630 m asl, 37°58'15.07"N, 13°12'2.23"E, [Lab ID 34_1, COI: MW758878; Lab ID 34_3, COI: MW758926; Lab ID 34_4, COI: MW758927],W. De Mattia and J. Macor leg., 22.iv.2017. 3 dissected spm. 8 Paratypes (CWDM 18224): same locality.

Shell diagnosis.

Shell decollate, rarely not decollate; whorls ribbed; dorsal keel weak but distinguishable; inferior lamella very high; anterior upper palatal plicae present and detached from the lunella; parietalis long; 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 19 .6-19.8, 24.7, 24.8). The shell is elongated, fusiform, sinistral, decollate but rarely not decollate. It is reddish-brown in colour. The external surface is regularly ribbed. The spire is slowly and regularly growing with (decollate) 8 to 9 ¼ slightly convex whorls. The sutures are moderately deep with whitish papillae present all along the teleoconch, moderately denser along the last whorls. The basal and the cervical keels are distinguishable. The umbilicus is closed. The aperture is ~ 1⁄5 of shell height and roundish to subovoid in shape. The PRI is short and ends at the level of the L. It is not fused with the L. The PRI is not visible from a frontal view of the aperture. The L is dorso-lateral, thick and somehow irregular. There is a very reduced, knob-like PUPP connected to it. The AUPP is strong to moderately weak, detached from the L and barely visible from the aperture. The BAS starts directly from the L and it is long and strong, well visible from the aperture. The SCL is absent. The IL is high to very high. The SUL is tooth-like, long and partially overlaps with the SPL. 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. The palatal edge against distal end is bent upwards and more or less blunt.

Measurements.

Holotype: not decollate shell height 20.3, whorl width 4.3, aperture height 3.8, aperture width 2.4. Paratypes (n = 25, decollate): shell height 20.9 ± 1.0, whorl width 4.4 ± 0.1, aperture height 3.9 ± 0.2, aperture width 2.4 ± 0.2.

External morphology of the genital organs

(Figs 18 .3, 18.6). The FO is longer than the V with a FO/V ratio ranging from 2.0 to 2.1. The VD is thin along its whole course. The ratio of the FDBC with the BC+SDBC (FDBC/BC+SDBC) ranges from 1.1 to 1.3. The BC+SDBC is club-like and longer than the V, with a blunt apex. It is slightly longer than the V, with a ratio (BC+SDBC/V) that ranges from 1.6 to 1.8. There is a clear distinction between the SDBC and the BC. The D is longer than the V (with a D/V ranging from 2.1 to 2.3) and slightly longer than BC+SDBC (D/BC+SDBC ratio 1.2-1.3). It is thinner than the BC+SDBC and with a small and round apex. The V is big and cylindrical. The A is large. The PC is longer than the V (P+E/V ratio 2.1-2.4). The PR is very short and robust. The ET is weak. The E is longer than the P (E/P ratio 1.1-1.2) and almost abruptly shrinking and turning into the VD.

Internal morphology of the genital organs

(Figs 18 .4, 18.7). The A shows few irregular pleats. The P presents 4 to 6 heavily segmented longitudinal pleats that begin directly from the PP and run as far as the A, becoming irregular as approaching their distal sections. The penial wall is smooth. The PP is big, rounded to rhomboid, smooth with a round to blunt apex. The P-E transition presents a first distal ER, while both the PP and ELP originate from the second proximal ER. The epiphallar formula is: 1ER+2ER(PP+ELP). The E shows a pattern of 4 to 6 smooth longitudinal pleats. These pleats merge one into another forming two main smooth pleats that run as far as the vas deferens. The V shows a weak irregular pattern of smooth pleats.

Comparative and taxonomical remarks.

The shell of Siciliaria calcarae jatinensis ssp. nov. is very similar to the shells of Siciliaria calcarae belliemii and Siciliaria calcarae parajatinensis spp. nov. The three taxa have markedly ribbed shells. The density of the ribs along the body whorl is similar, with overlapping ranges: 32 ± 5 for Siciliaria calcarae belliemii (n = 25), 35 ± 6 for Siciliaria calcarae jatinensis ssp. nov. (n = 21) and 34 ± 5 for Siciliaria calcarae parajatinensis spp. nov. (n = 15). The PRI are short and stop at the level of the L, whereas the AUPP is strong to moderately weak and detached from the L. Slight differences are observed concerning the dimensions and the colour of the shell: Siciliaria calcarae jatinensis ssp. nov. is dark reddish to dark brown with an average height of 20.9 ± 1.0 whereas Siciliaria calcarae parajatinensis ssp. nov. (average height: 21.7 ± 1.4) and Siciliaria calcarae belliemii (average height: 17.6 ± 1.2, type locality) are light yellowish to light brown. The three subspecies show just slight differences in their anatomy of the genital organs, which fit into the intraspecific variability of S. calcarae and do not allow a certain separation. The different subspecific status of these populations is mainly supported by the phylogenetic results in connection to their patchy and isolated distribution. Siciliaria calcarae jatinensis ssp. nov. is included in the haplogroup 2 whereas Siciliaria calcarae parajatinensis n. spp. and Siciliaria calcarae belliemii both belong to haplogroup 1.

Nordsieck (2013a) recently supplemented his Siciliaria web article (May 2021) after receiving samples we collected from Monte Jato ( S. calcarae jatinensis ssp. nov.) and the W side of Monte Kumeta ( S. calcarae parajatinensis ssp. nov.), considering these populations as belonging to the type form of Siciliaria tiberii and, more precisely, "to the southern and eastern form with less strong dorsal keel". Nordsieck (2013b, supplemented 2021) justifies his identification stating that "There is no doubt that Clausilia tiberii A. Schmidt (1868: 42-43) belongs to the southern form" despite not justifying or explaining why "there is no doubt", considering also that no locality is provided in Schmidt’s description.

Nordsieck (2013b, supplemented 2021) stated that "Originals from Benoit (SMF 67544, 96458, see also Benoit 1859: pl. 6, fig. 7) do not differ from the form from Monte Kumeta". Following the caption of fig. 10 "M. della Scala" was wrongly identified by Nordsieck as Monte Kumeta. Information provided by locals during field collections allowed us to ascertain that Monte della Scala is an old, almost forgotten toponym for Monte Maganoce. Monte Maganoce was once named "Monte della Scala" because of the church called "Madonna della Scala" was located along its slopes.

Moreover, in the text Nordsieck cited samples SMF 67544, 96458, while in fig. 10 the caption indicated the sample as "N 10008". Thus, it is not clear if the depicted specimen originated from Benoit or from a different source and kept in Nordsieck´s collection.

Monte Kumeta was also deemed by Nordsieck as a spelling mistake for Monte della Fiera (pers. comm., April 2021) and stating that "form from Monte della Fiera belongs to the northern subspecies (of S. tiberii ), based on SMF samples". Monte della Fiera (37°59'47.90"N, 13°8'48.22"E) is 10 km distant from Monte Kumeta and represents the eastern continuation of Monte Belliemi. It is not clear what the "northern subspecies" may be, but probably it is referred as the northern form of the nominate subspecies.

In the COI and combined tree (Fig. 4 ) S. calcarae jatinensis ssp. nov. is well embedded into Siciliaria calcarae subclade A2. The morphologically similar S. calcarae parajatinensis ssp. nov. is also well embedded into S. calcarae clade in the COI tree.

We agree that the sample depicted in Fig. 10 is similar to S. calcarae jatinensis ssp. nov., but it is not clearly explained by Nordsieck (2013b; supplemented 2021) why it is supposed to belong to S. tiberii . To check this hypothesis, we included in our molecular genetic analysis two specimens of S. tiberii tiberii from Capo Rama (Terrasini) representing the “northern” form in both COI and concatenated trees, they fall well embedded within the subclade that comprises all (and exclusively) the remaining S. tiberii subspecific taxa.

Regarding shell morphology, we carefully browsed Schmidt’s description (1868: 41-43). Few important details better fit with the shell morphology of the “northern” type form of Siciliaria tiberii (Figs 26 .1, 26.3) rather than with the specimen depicted by Nordsieck (2013b, supplemented 2021, fig. 10) and the specimen we depicted in Figs 19 .9-19.11. Schmidt refers to the more expanded peristome ("mehr umgeschlagene Mündung"), the deep dorsal keel ("sendet nach unten eine stark entwickelte Gaumenfalte ab, welche auf der, durch die tiefe, breite Nackenfurche gebildeten, inneren Wölbung steht") and the deep palatal hollow. Other shell differences are detectable comparing Figs 19 .9-19.11 and Figs 26 .1, 26.3, the number and shape of the ribs of the neck and along the whorls, strength and visibility of the AUPP, the length of the PRI, the presence of a second lower AUPP in S. calcarae parajatinensis ssp. nov., the strength and visibility of the sutural papillae, the depth of the sutures and the more convex whorls of S. tiberii tiberii . Thus, phylogenetic and morphological evidence prevent us from considering the Monte Jato and Monte Kumeta populations as belonging to S. tiberii .

Distribution.

Siciliaria calcarae jatinensis ssp. nov. is known only from the type locality: the abandoned quarry north of the town of San Giuseppe Jato. Its actual distribution range must be further investigated as it is probably present along the northwestern cliffs of the Monte Jato, E of the town of San Giuseppe Jato.

Ecology.

The new subspecies is an obliged limestone rock-dweller, exclusively collected on walls and cliffs, both natural or resulting from the previous quarrying activity.

Etymology.

Siciliaria calcarae jatinensis ssp. nov. is named after Monte Jato (San Giuseppe Jato), where the new subspecies was 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 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 10. Siciliaria septemplicata (Philippi, 1836), Monte Gallo, Sferracavallo 10.1 shell 10.2 detail of the aperture 10.3 clausiliar plate 10.4 shell 10.5 detail of the aperture 10.6 detail of the columellar side of last whorl 10.7 clausiliar plate double side.

Figure 18. Siciliaria calcarae borgettensis ssp. nov., road to Romitello, Borghetto 18.1 whole distal genital organs 18.2 internal distal part of genital organs. Siciliaria calcarae jatinensis ssp. nov. San Giuseppe Jato 18.3 whole distal genital organs 18.4 internal distal part of genital organs 18.5 detail of the pseusopapilla 18.6 whole distal genital organs 18.7 internal distal part of genital organs. Siciliaria calcarae parajatinensis ssp. nov., west side Monte Kumeta 18.8 whole distal genital organs 18.9 internal distal part of genital organs.

Figure 19. Siciliaria calcarae borgettensis ssp. nov., road to Romitello, Borghetto 19.1 shell 19.2 detail of the aperture 19.3 clausiliar plate double side 19.4 shell 19.5 detail of the aperture. Siciliaria calcarae jatinensis ssp. nov. San Giuseppe Jato 19.6 shell 19.7 detail of the aperture 19.8 clausiliar plate double side. Siciliaria calcarae parajatinensis ssp. nov., west side Monte Kumeta 19.9 shell 19.10 detail of the aperture 19.11 detail of the columellar side of last whorl 19.12 clausiliar plate double side.

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.