K. cf. sinuata

Grego, Jozef, Mumladze, Levan, Falniowski, Andrzej, Osikowski, Artur, Rysiewska, Aleksandra, Palatov, Dimitry M. & Hofman, Sebastian, 2020, Revealing the stygobiotic and crenobiotic molluscan biodiversity hotspot in Caucasus: Part I. The phylogeny of stygobiotic Sadlerianinae Szarowska, 2006 (Mollusca, Gastropoda, Hydrobiidae) from Georgia with descriptions of five new genera and twenty-one new species, ZooKeys 955, pp. 1-77 : 1

K. cf. sinuata

Other material.

Georgia • Imereti, Samegrelo, Pirveli Balda, Motena Cave (მოტენას მღვიმე), sandy sediment at terminal sump lake; 42°28'36"N, 42°23'29"E; 485 m a.s.l.; 09 May 2018; J. Grego, L. Mumladze and M. Olšavský leg. • Samegrelo, Pirveli Balda (პირველი ბალდა), spring at village; 42°29'2"N, 42°23'53"E; 295 m a.s.l.; 09 May 2018; J. Grego, L. Mumladze and M. Olšavský leg. • same as preceding; 13 October 2019; J. Grego leg.

Diagnosis.

The new species differs from all known stygobiotic gastropods by the characteristically and deeply sinuated labral margin with two to three large tooth-like folds. The two most closely related species, Kartvelobia kinchkha sp. nov. and Kartvelobia shishaensis sp. nov., have only weakly sinuated labral margin and generally smaller shell. Compared to K. kinchkha sp. nov. the protoconch is smoother and to K. shishaensis sp. nov. it is more conspicuously pitted. Both of the latter species generally have smaller shells.

Description.

Shell: shape is ovate-conical, 1.36-2.07 mm high with four whorls separated by a deep suture, a blunt protoconch, and a closed umbilicus. Shell surface whitish, translucent, smooth to glossy, with very faint growth lines. The aperture ovate-ellipsoid with its axis declined from columella by 38° and separated from the body whorl by a gap or groove. Its labral margin characteristically sinuated with a deeply cut broad round shaped adapical sinulus, continuing with a triangular tooth-like structure curved inward, and smoothly followed by two more, similar tooth-like structures down to lower extremity of the shell. The wavy labral margin varies significantly within the species. The lateral profile of the columellar margin more-or-less straight. The protoconch surface very weakly pitted.

Operculum: yellowish, translucent, elongate ellipsoid, paucispiral with an excentric nucleus.

Animal body: milky whitish coloured, eyeless.

Holotype measurements: H-1.67 mm; W-0.96 mm; BH-1.16 mm; BW-0.81 mm; AH-0.76 mm; AW-0.61 mm; CA: 38°.

Anatomy: the penis (Fig. 9A-D ) simple, broad and massive, proximally bent, with a small outgrowth in the middle of its left side, the vas deferens running straight. The female reproductive organs (Fig. 9E ) with a short and broad oviduct loop, small distal receptaculum seminis (at the position of rs1 of Radoman: see Szarowska (2006)) and big spherical bursa copulatrix with a long duct.

Etymology.

Named after the conspicuously sinuated labral margin.

Habitat.

The empty shells of the new stygobiotic species were found in the sandy sediments of several cave streams or karst spring heads. Few live individuals were found in a small concrete basin built on a small permanent spring emerging from a fissure in the thick limestone beds. The individuals of this hypogean species were washed out from its stygobiont habitat and accumulated in the small artificial basin.

Distribution.

This species is known from the Pakhe karstic plateau NW of Kinchkhaperdi and Satsiskvilo (south of the Askhi Plateau) in the caves and springs emerging from cliffs at its foot and slopes, as well from the springs and caves at Turchu Gamosadivari Basin situated at the top of the plateau the Turchu Gamosadivari River sink at the western edge of the basin, and appearing again in First Toba Cave and in Arsen Okrojanashvili Cave. A more conical form of the new species with slightly different labral margin ( K. cf. sinuata is known from the southernmost tip of the Pakhe Plateau massif, from the springs in village Pirveli Balda and from Motena Cave. A local form with minute shell, inflated whorls is found around Kinchkhaperdi below the NW foot of the plateau. The taxonomic status of both forms should be clarified.

Conservation status.

The number of known locations is 11 and EOO is ca. 70 km2. The AOO is represented by only several underground karst conduits with much smaller total area compared to EOO. Each karst conduit is supplied by surface water through swallow holes, where stochastic events, as human driven pollution or habitat destruction, could lead to rapid species decline or extinction. Therefore, it is assessed as Vulnerable (VU) D2.

Remarks.

The labral sinuation intensity can vary by specimen, especially juvenile individuals have only weakly developed sinuation.

Figures

Figure 9. Kartvelobia sinuata sp. nov., Imereti, Satsiskvilo, Turchusmtha, morphology of the reproductive organs A-D morphology of the penis E female renal and pallial section of reproductive organs. Bc - bursa copulatrix; cbc - duct of bursa copulatrix; ga - albuminoid gland; gn - nidamental gland; gp - gonoporus; ov - oviduct; ovl - loop of oviduct; rs - receptaculum seminis; vc - ventral channel. Photograph and drawing A. Falniowski.