Virpazaria (Aemiliella) ripkeni arbeni Gittenberger, 2015

Fehér, Zoltán, Deli, Tamás, Erőss, Zoltán P. & Lika, Romilda, 2019, Taxonomic revision of the subterranean genus Virpazaria Gittenberger, 1969 (Gastropoda, Spelaeodiscidae), European Journal of Taxonomy 558, pp. 1-25 : 21-22

Virpazaria (Aemiliella) ripkeni arbeni Gittenberger, 2015

Virpazaria (Aemiliella) ripkeni arbeni Gittenberger, 2015: 27 , fig. 8.

Diagnosis

The upper palatal lamella which does not or hardly reaches the peristome and the non-thickened, knobless peristome are the features that distinguish this subspecies from the nominate subspecies.

Material examined

Holotype

ALBANIA • Shkodër, Rozafa Cave [= Shpella e Rozafës]; 42.0487° N, 19.4938° E; 18 Oct. 2011; E. Gittenberger leg.; RMNH 5003974 [not seen].

Paratypes

ALBANIA • 2 spec.; same locality as for holotype; May 2013; M. Slooff leg.; RMNH 5003975 [not seen] .

Dimensions

H 1.7–1.8 mm; W 3.1–3.2 mm (based on three specimens according to Gittenberger 2015).

Distribution

Recent records of this species are from the southern rim of the Shkodër Lake Basin, from the surroundings of Shkodër. The Shkodër site is located on Upper Triassic, the Drisht site on Middle Triassic and the Renc Mts site on Upper Cretaceous limestone. If these were the only known localities, this would already make V. ripkeni the widest distributed species of its genus. Strangely, the type locality of the nominate subspecies is located at the northwestern side of the Shkodër Lake Basin, very far from these Albanian sites (but see Remarks).

Remarks

This species was described on the basis of eight specimens. Their width and height are 3.5–4.0 mm and 2.05–2.25 mm, respectively, and the number of ribs on the last whorl is 73–86. In the original description ( Gittenberger 1969) somewhat lower values were given, probably because he applied a different measuring method. The holotype of V. pastorpueri is 3.6 mm wide and 2.15 mm high with 60 ribs on its last whorl (although Reischütz et al. (2011) provided a smaller width (3.0– 3.5 mm), a larger height (2.5 mm) and an average of 65 ribs on the last whorl). Smaller and more tapered shells were defined by Reischütz et al. (2011) as the most important features to distinguish V. pastorpueri from V. ripkeni . Later, Gittenberger (2015) studied a larger series of topotypical V. pastorpueri specimens and concluded that their shells are neither smaller nor relatively higher and thicker discoid than those of typical V. ripkeni . However, he found that the ribbing of V. pastorpueri is less dense (less than 70 ribs on the last whorl) and therefore he preserved it as a distinct subspecies, V. ripkeni pastorpueri . In the same paper, Gittenberger described another subspecies, V. ripkeni arbeni , which is smaller (H 1.7–1.8 mm; W 3.0– 3.1 mm) and has a weakly developed peristome.

We collected several hundred specimens of this species at four different locations in the Renc Mts. Their shell width ranges between 2.7 and 3.6 mm, shell height between 1.5 and 2.1 mm and the number of ribs on the last whorl between 60 and 82. Compared to topotypical V. pastorpueri , their size, shape and rib density values largely overlap. Although one might say that they are generally somewhat smaller and more tapered than typical V. ripkeni , neither these characters nor the rib density are able to provide a clear-cut distinction. This large variability in rib density refutes Gittenberger’s argument ( Gittenberger 2015), and makes any distinction between V. pastorpueri and V. ripkeni meaningless. However, none of the many adult specimens from the Renc Mts have such a weakly developed peristome as in the three specimens that were described as V. ripkeni arbeni . Having no more material available from the type locality of V. r. arbeni (Shkodër) , it is not possible to test whether the entire population consistently has an underdeveloped peristome there or the subspecies was described on the basis of three freak individuals. Until this question is settled, we must preserve V. ripkeni arbeni .

The type material of V. ripkeni was presumably collected by Petar Dabović in the 1930s, passed somehow to the Viennese private collector Aemilian Edlauer, and finally landed in the NHMW Mollusc Collection. It appears that Edlauer, or someone else who studied his collection, recognized, but never described, three different species of Virpazaria . The proposed names were ʻ Trissexodon kuščeri ʼ, ʻ Trissexodon montenegrina ʼand ʻ Trissexodon Käufeli ʼ. The latter name was obviously proposed for V. pageti , but the situation is more dubious with the other two. Among the lots of V. adrianae we could find both ʻ Trissexodon kuščeri ʼ and ʻ Trissexodon montenegrina ’ labels, whereas the name ʻ Trissexodon kuščeri ’ also appears in the material of V. ripkeni . Gittenberger (1969) mentioned eight type specimens of V. ripkeni from the same original lot (of which one was designated as a holotype, one made its way to the RMNH and six remained in the original vial and kept the original labels (NHMW 77153a)). Interestingly, another site, “Pečina Grbočica bei Virpazar”, is indicated on the original label in that vial, whereas “Soko Höhle bei Dupilo”, which is given in the description, can be found on a newer label written in someone else’s handwriting. Furthermore, there is another lot (NHMW 77154), which is from Soko Cave according to the original label and contains one specimen of V. ripkeni , but not mentioned by Gittenberger (1969). Even stranger, this lot contains an original Edlauer label with the same locality, the same voucher number (E-57441) and the same proposed name, ʻ Trissexodon kusceri ’, as the type lot of V. adrianae . It seems very difficult, if not impossible, to trace back whether there was any mixup with the labels or the specimens in the past, and, if so, where exactly the type specimens of V. ripkeni came from (Soko?, Grbočica? or from somewhere else?). The fact that neither Gittenberger (1975) nor anyone else has been able to refind V. ripkeni at its alleged type locality or anywhere else in the Virpazar area further discredits the validity of the type locality.