Zospeum gittenbergeri Jochum, Prieto & De Winter

Jochum, Adrienne, E. Prieto, Carlos, Kampschulte, Marian, Martels, Gunhild, Ruthensteiner, Bernhard, Vrabec, Marko, D. Doerge, Dorian & J. de Winter, Anton, 2019, Re-evaluation of Zospeumschaufussi von Frauenfeld, 1862 and Z. suarezi Gittenberger, 1980, including the description of two new Iberian species using Computer Tomography (CT) (Eupulmonata, Ellobioidea, Carychiidae), ZooKeys 835, pp. 65-86 : 65

Zospeum gittenbergeri Jochum, Prieto & De Winter sp. n. Figures 5L, N–R, 13, 14

Zospeum schaufussi - Gittenberger 1980: 203, Fig. 1. [non Zospeum schaufussi von Frauenfeld, 1862]

Type material.

Holotype (RMNH 234166/1 shell): Cueva del Puente de Inguanzo (Inguanzo, Concejo de Cabrales, Asturias, Spain), MGRS 30TUN4897097640 (N43.315574, W4.860905), 230 m a.s.l., 19.02.1979, leg. G Favre & R Emery. Other material: former Z. suarezi paratype shells mentioned in Gittenberger (1980): data as holotype: MHNG 96219/4 shells (now lost) (Fig. 5L, N–R).

Diagnosis.

Holotype shell conical, larger than most Iberian Zospeum , SH nearly 1.5 mm with 5 1/2 moderately convex whorls. Parietal part of peristome straight and long, giving the peristome an angular rather than convex appearance. Internally, the lamella circumscribing the columella is very weak, but it is unclear if this is due to erosion or if it is covered by debris (Fig. 14 G–J).

Description.

Measurements of holotype provided in Table 1. Lost specimen of imaged MNHG 96219 shell (Fig. 5 N–R) is smaller than holotype (SH 1.22 mm). Shell elongate-conical with approximately 5 ½ rounded whorls, regularly coiled, suture deep; teleoconch smooth with occasional blunt growth lines (Fig. 14 A–D); aperture more or less circular; peristome closely adhering to spire, reflected, moderately thickened, with an angular, relatively long parietal callus; columella straight and aligned axially, single lamella small and non-extending, coiled tightly around the columella; columellar apertural edge (side view, aperture facing right) and the border of the parietal callus join at an angle of ca. 90 degrees (Fig. 13C); umbilicus closed, umbilical depression deep, moderately strong, wrinkly striae descend from last whorl behind apertural lip leading to umbilicus; apertural barriers lacking.

Differential diagnosis.

Differs from Z. biscaiense by the larger, more elongate shell and the absence of major apertural barriers; from Z. schaufussi (lectotype) by its long and angular parietal callus, straight, axially aligned columella and its small, non-extensive, tightly coiled lamella; in Z. bellesi , columellar elaboration is completely absent; from Z. vasconicum by its non-rounded aperture, more robust, axially aligned columella; from Z. zaldivarae by its more elongate shell, lack of apertural barriers; from Z. percostulatum by its non-costulate shell; from Z. praetermissum sp. n. by its long, parietal edge of the angular peristome and different columellar morphology.

Etymology.

The new species is named in honour of Prof. Edmund Gittenberger, in recognition of his pioneering work on Iberian Zospeum .

Distribution.

Only known from the type locality.

Ecology.

According to the records of the collector, Gérald Favre (pers. comm. 2017), the collection site was located ca. 200 m from the cave entrance. His field notes document that the area consisted of sandy substrate, some chestnut fragments and that the humidity level was low.

Remarks.

We formally describe the specimen illustrated by Gittenberger as a separate species. We confine the type material to the one shell known from the type cave. Although Gittenberger (1980) mentioned similar, but much less elongate shells from another cave (Cueva del Búho), we prefer to address these as Z. cf. gittenbergeri (Fig. 13 F–I). Shells with this shape and apertural morphology occur in various caves in sympatry with a schaufussi -like (in its present sense) species. This is seen for example in shells from Cueva del Linar (C. la Busta), where shells with angular peristomes, but much smaller than the holotype shell (SH 0.95 - 1.15; SD 0.64 - 0.74 mm) occur sympatrically with shells that are externally and internally indistinguishable from Z. schaufussi . Internal morphology of the Cueva de Linar shells so far shows a simple, tightly coiled singular lamella around the columella (unpubl. results, Jochum). Further study is needed to define Z. gittenbergeri , especially using molecular data.

A number of confusing discrepancies surfaced in addressing Gittenberger’s (1980) material from Cueva del Puente de Inguanzo. Gittenberger (1980) cited only 1 shell (corresponding to the data of specimen MHNG 96219) for Z. schaufussi (= Z. gittenbergeri sp. n.), which he measured (1.45 mm) and illustrated (fig.1). For this shell, he cites "Cueva de Inguanzo near Inguanzo, 2 km SW of Cabrales, between Covadonga and Panes, Oviedo; UTM U N 4 9; G. Favre & R. Emery leg., 19.ii.1979 (MHNG/i shell; RMNH/i shell)." However, our Figure 5 (L, N–R) is the shell imaged by the curator, Emmanuel Tardy, at the MHNG (2017) but it only measures 1.22 mm and does not correspond to the illustrated shell. On the other hand, the shell chosen as holotype (RMNH.234166), measures 1.49 mm and fits the one Gittenberger (1980) illustrated. It appears that Gittenberger (1980, fig. 1) erroneously indicated MHNG as the collection provenance of the shell, which is actually, the single shell at the RMNH.

An additional source of confusion is that there are two caves with similar, but not identical names referring to the town of Inguanzo, which are situated within one kilometer of each other (Fig. 15). The type cave, Cueva del Puente de Inguanzo, from where Gittenberger’s (1980) material derives, is a different cave from where Weigand et al.'s (2013) material, from Cueva de Inguanzo (= Cueva de Bosque), derived. These two caves are separated by the Casaño River and it is not known if the two cave systems are contiguous. This important consideration became apparent when we contacted the collector of Gittenberger’s (1980) material.