Ruthenica filograna (Rossmaessler, 1836)

Egorov, Roman, 2022, A new subspecies of Ruthenica filograna (Pulmonata: Clausiliidae) from Croatia, Ruthenica, Russian Malacological Journal (Philadelphia, Pa.) 32 (1), pp. 49-52 : 49-50

Ruthenica filograna pocaterrae subsp. nov.

Fig. 2A 1-A 6

Zoobank registration: urn:lsid:zoobank. o r g:a c t: 8 A D 0 6 2 E C - 4 2 D 3 - 4 2 B1 - A E C C - C81A545949EB

Type material. Holotype ( SMF 360698 ), dry

sample; 1 paratype in ZMMU (Lc-40945), dry sample ; 3 paratypes in private collection of Roman Egorov, dry samples; 4 paratypes in private collection of Giuseppe Pocaterra. All specimens are from the type locality.

Type locality. Croatia, western coast of Istria, south of Porec, near Limski Channel , in litter under trees, VI.2006, coll. Giuseppe Pocaterra.

Description. Shell is elongated, fusiform, three upper whorls (embryonic) are cylindrical. Penultimate whorl is only slightly wider than the body whorl. There are 19-22 ribs on the body whorl and 18-20 on the penultimate one. Aperture is regularly pyriform, distinctly semi-apostrophic. In studied specimens, palatal callus absent or rather weakly developed. Superior lamella is rather low, reach the edge of aperture. Inferior lamella smoothly bends up and connected with lip by one fold. Subinterlamellar fold is absent. Subcolumellar lamella well developed, lying deep and practically not visible in front view.

Dimensions. Holotype: H – 10.2 mm, D – 1.78 mm, Hap – 1.62 mm, WAp – 1.31 mm; paratypes: H – 8.9-9.92 mm, D – 1.24-1.78 mm, Hap – 1.51- 1.70 mm, Wap – 0.98-1.12 mm.

Etymology. Named in honor of Giuseppe Pocaterra which untimely departed from us on 08.03.2016. Giuseppe has collected described here samples.

Distribution. Known only from the type locality.

Discussion. The new subspecies differs from the nominotypical and other subspecies in the following shell characters: shell slender, body whorl very elongated, 3 embryonic below 1.25 uppermost whorls equal in width, aperture distinctly semi-apostrophic, lower whorls covered by widely spaced lamellate axial ribs. Slovenian specimens are similar to the nominatypical subspecies in its shell characters ( Fig. 2D 1-D 3). Upper whorls (except 1.25 uppermost) of the new subspecies are almost equal in width ( Fig. 2A 5) while they are different in width at nominotypical subspecies ( Fig. 2A 6). Also, in comparison with all other subspecies R. filograna pocaterrae is more strongly and on average more spacely ribbed on last two whorls.

Also, new subspecies differs from R. gallinae in less detached aperture, character of axial sculpture and geographical distribution.

Ruthenica f. filograna was recorded in Croatia [ Štamol, 2010] and R. filograna s.l. mentioned as occurring “frequently on the adjoining mainland” [ Štamol, Velkovrh, 1995: 234]. However, there is no description and illustrations of the shells of mentioned specimens.Also, the species is mentioned from Cres and Losinj islands, also without description of shell [ Štamol, Velkovrh, 1995]. Therefore, I cannot say whether these specimens belong to described herein subspecies.

Thus, Ruthenica filograna is most widely distributed species of the genus and includes 5 subspecies: R. f. filograna (Rossmaessler, 1835) , R. f. catarrhactae Bielz, 1861, R. f. kimakowiczi Nordsieck, 2019, R. f. streicola Nordsieck, 2019, and R. f. pocaterrae subspec. nov.

Figures

FIG. 1. Schematic map of distribution of Ruthenica filograna pocaterrae ssp. nov. (red circle) and Ruthenica filograna s.l. (black circles) in the South-western part of the area.