Caucasopsis olsavskyi Mumladze & Grego, 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

Caucasopsis olsavskyi Mumladze & Grego sp. nov. Plates 9 (1); 10(3)

Type locality.

Georgia • Samegrelo, Chkhorotsku, Nazodelavo Cave (ნაზოდელავოს მღვიმე); 42°30'18"N, 42°13'15"E; 275 m a.s.l.; sandy sediment in cave stream.

Material.

Holotype: Georgia • 1 adult, dry; type locality; 11 May 2018; J. Grego, L. Mumladze and M. Olšavský leg.; ISU FM-T009-H. Paratypes: Georgia • same as for holotype; ISU FM-T009-P1/ dry, NHMW 113369/1 dry, coll. JG F1053/2 dry, coll. Glöer /1 dry.

Diagnosis.

The new species differs from its closest relatives by its oval shell shape, proportionally smaller aperture more close-set to the columella and closed umbilicus. There is some similarity to the shell shape of C. subovata (Starobogatov, 1962) from Abkhazia, however, the broken subfossil type does not allow more detailed comparison, and the drawing of the author within the description was likely just a reconstruction of the broken holotype.

Description.

Shell: is 1.50-1.96 mm high, elongate ovate-conical with rounded whorls and blunt apex. Surface smooth, whitish, occasionally with inorganic incrustations. Aperture proportionally small, flat-ovoid shaped, situated below larger body whorl. Lateral profile of labral margin straight, columellar margin very weakly sinuated. Umbilicus closed.

Operculum: not known.

Animal body: not known.

Holotype measurements: H-1.87 mm; W-0.85 mm; BH-0.94 mm; BW-0.77 mm; AH-0.60 mm; AW-0.45 mm; CA: 26°.

Anatomy: not known.

Etymology.

Named for our friend Mário Olšavský, geologist and speleologist from Banská Bystrica, Slovakia, who actively participated in the field trip to Georgia.

Habitat.

Stygobiotic species. Empty shells were found at the sandy bottom of the cave stream inside a conglomerate cave. The empty shells were very scarce, as an undetermined Tschernomorica sp. was more abundant in the type locality.

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.

Figures

Plate 9. 1 Caucasopsis olsavskyi sp. nov., Samegrelo, Chkhorotsku, Nazodelavo Cave, holotype 2 C. letsurtsume sp. nov., Samegrelo, Chkhorotsku, Letsurtsume, Letsurtsume Cave, holotype 3 C. letsurtsume sp. nov., Samegrelo, Chkhorotsku, Kachara Cave 4 C. egrisi sp. nov., Samegrelo, Pirveli Balda, Motena Cave form 5, 6 C. egrisi sp. nov., Samegrelo, Pirveli Balda, spring in village: 5 holotype 6 paratype 7 Imeretiopsis prometheus sp. nov., Imereti, Kumistavi, Prometheus Cave, holotype 8 I. cameroni sp. nov., Imereti, Kutaisi, Iazoni (Tskhal-Tsiteli) Cave Spring, holotype 9 I. nakeralaensis sp. nov., Imereti, Tikibuli, spring above Tikibuli-Nikortsminda road to Nakerala pass, holotype 10 C. letsurtsume sp. nov., Samegrelo, Chkhorotsku, Letsurtsume, Letsurtsume Cave, robust morphotype. The numbers correspond to individuals, and the letters represent the different views of the same individual. Photograph J. Grego.