Imeretiopsis iazoni Grego & Mumladze, 2020

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

Imeretiopsis iazoni Grego & Mumladze sp. nov. Plate 8 (5-6)

Type locality.

Georgia • Imereti, Kuatisi, Iazoni (Tskhal-Tsiteli) Cave Spring (იაზონის იგივე წყალ-წითელას მღვიმე), right bank of Tskalsitela River Canyon; 42°16'18"N, 42°44'02"E; 145 m a.s.l.; sandy sediment inside the cave.

Material.

Holotype: Georgia • 1 adult, dry; type locality; J. Grego, L. Mumladze and G. Bananashvili leg.; ISU FM-T014-H. Paratypes: same as for holotype, ISU FM-T014-P1/1 dry, coll. JG F1409/1dry.

Diagnosis.

The species differs from the most closely related Imeretiopsis gorgoleti sp. nov. by its much smaller, less inflated shells with proportionally smaller and less expanded aperture and by the smaller umbilicus. From the other stygobiotic gastropods of the region with similar shell shape it differs by its smaller shell with the sinuated lateral labral profile. From the sympatric I. cameroni sp. nov. it differs by the much smaller shell, more inflated whorls, flatter apex and more open umbilicus. Measurement comparison Imeretiopsis species is given in Table 5 .

Description.

Shell: rather small, 1.38-1.47 mm high, elongate-conical with four whorls, blunt and flat apex, inflated whorls and deep suture. Umbilicus narrow, almost closed. Shell surface glossy, milky white with irregular growth lines, randomly forming faint, rib-like structures. Aperture irregularly oval, slightly depressed from columellar side and slightly expanded. Lateral labral profile very weakly sinuated, columellar profile rather straight.

Operculum: not known.

Animal body: not known.

Holotype measurements: H-1.47 mm; W-0.74 mm; BH-0.85 mm; BW-0.68 mm; AH-0.50 mm; AW-0.47 mm; CA: 35°.

Anatomy: not known.

Etymology.

Named after the type locality, Iazoni Cave (იაზონის მღვიმე) (= Tskal-Tsiteli = Rioni Cave (= წყალწითელას = რიონის მღვიმე)) in Kutaisi.

Habitat.

Stygobiotic species. See habitat of Imeretiopsis cameroni sp. nov.

Distribution.

Only known from the type locality.

Conservation status.

The number of known locations (1) is no more than 5 and EOO is smaller than 20 km2. There is no reason to suppose that AOO, EOO, number of locations, number of subpopulations or the number or mature individuals are declining however due to its extremely small EOO we assessed as Vulnerable (VU) D2.

Remarks.

The assignment to the genus Imeretiopsis gen. nov. is only provisional due to sinuated aperture margins and resemblance to I. gorgoleti . sp. nov.; molecular data will be needed to determine its true taxonomic status. The type locality has indications of occasional pollution, and most of the stygobiotic Mollusca endemic to the cave ( M. borutzkii (Shadin, 1932), Euglesa subterranea (Shadin, 1932) and Imeretiopsis cameroni sp. nov.) have shown declining populations. The new species is scarcer than all of the sympatric species.

Figures

Plate 8. 1 - 4 Imeretiopsis gorgoleti sp. nov., Racha, Gorgoleti, small spring above the road to Tsakhi: 1 holotype 2 paratype NHMW 113279 3, 4 paratypes 5, 6 I. iazoni sp. nov., Imereti, Kutaisi, Iazoni Cave: 5 holotype 6 paratype 7, 8 I. cameroni sp. nov., Imereti, Kutaisi, Iazoni Cave, paratypes 9 - 13 I. gorgoleti sp. nov., specimens used for molecular and anatomical studies 14 I. gorgoleti sp. nov., operculum. The numbers correspond to individuals, and the letters represent the different views of the same individual. Photograph Sara Schnedl, NHMW, and A. Rysiewska.