taxonID	type	description	language	source
6870E7405A5651009774107EC7CA6B44.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 12 October 2019; J. Grego, L. Mumladze and G. Bananashvili leg.; ISU FM-T 001 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 001 - P 1 / 12 dry and 24 wet, SBMNH 633099 / 2 dry, NHMW 113365 / 1 dry, HNHM 104678 / 1 dry, NHMUK 20191334 / 2 dry, NHMB 563964 / 1 dry, SMF 358925 / 1 dry, NHMW 113365, ZMH 140630 / 1 dry, MNHN-IM- 2016 - 7895, ZIN 1 / 507 - 2020 / 1 dry, coll. JG F 1414 / 15 dry and 24 wet, coll. Gloeer / 1 dry. • same as for holotype; 10 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG F 1041 / 2 dry. Other material: Georgia • Samegrelo, Mapeli Cave, Mukhuri, water catchment (above cemetery); 42 ° 38 ' 22 " N, 42 ° 11 ' 39 " E; 325 m a. s. l.; 10 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG / 3 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6870E7405A5651009774107EC7CA6B44.taxon	diagnosis	Diagnosis. The new species differs from all congeners by its smaller more elongate-conical shell with more numerous whorls combined with a smaller umbilicus. The aperture sinuation shows similarity with C. gloeri sp. nov., however, the latter has a larger, more robust and less elevated shell shape with the columellar sinuation. Caucasogeyeria colchis sp. nov. differs from new species by its larger size and more deeply sinuated labral margin. Measurement comparison of Caucasogeyeria species is given in Table 8.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6870E7405A5651009774107EC7CA6B44.taxon	description	Description. Shell: elongate conical with five tumid whorls, a semi-deep suture, a blunt apex and a narrow umbilicus. Height 1.40 - 1.93 mm. Shell surface smooth, covered by a milky white periostracum, frequently overlaid by thick dark brown-black inorganic precipitate. The expanded aperture irregularly pear shaped. Labral margin with a weak but broad negative sinuation near the body whorl junction, followed by a characteristic inward curved but shallow labral fold. Columellar margin is straight, not sinuated. Protoconch surface regularly pitted, pitting fading out at the nucleus. Operculum: light yellow, paucispiral with central nucleus. Animal body: without eye spots, not pigmented, whitish translucent. Holotype measurements: H- 1.93 mm; W- 1.21 mm; BH- 1.21 mm; BW- 1.07 mm; AH- 0.84 mm; AW- 0.65 mm; CA: 30 °. Anatomy: penis (Fig. 14 D) straight, simple, without any outgrowth.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6870E7405A5651009774107EC7CA6B44.taxon	etymology	Etymology. Name derived from the Greek name Chrysomallos, meaning Golden Fleece (symbol of authority and monarchy), which, according to Greek mythology, was held in Colchis. Jason and his crew of Argonauts were sent out on a quest for the Golden Fleece by order of King Pelias.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6870E7405A5651009774107EC7CA6B44.taxon	distribution	Distribution. Only known from the type locality and from Mapeli Cave.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1F98E04660265385A465B8ED3A38FFBF.taxon	materials_examined	Material. Holotype: Georgia • 1 adult dry; Type locality; 09 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 002 - H. Paratypes: Georgia • same as for holotype; coll. JG T 1036 / 1 dry; • Samegrelo, Pirveli Balda (პირველი ბალდა), spring in village above road; 42 ° 29 ' 2 " N, 42 ° 23 ' 53 " E; 295 m a. s. l.; 09 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 002 - P 1 / 12 dry, SBMNH 633068 / 4 dry, NHMW 113362 / 1 dry, coll. JG F 1034 / 12 dry. • same as preceding; same as preceding; 12 October 2019; J. Grego leg.; ISU FM-T 002 P 2 / 5 dry, HNHM 104676 / 1 dry, NHMB 563962 / 1 dry, SMF 358923 / 1 dry, coll JG F 1434 / 37 dry. Other material: Georgia • Imereti, Nakhriduri 6, left tributary rivulet under travertine waterfall; 42 ° 29 ' 7 " N, 42 ° 31 ' 22 " E; 960 m a. s. l.; 03 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG / 4 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1F98E04660265385A465B8ED3A38FFBF.taxon	diagnosis	Diagnosis. The C. colchis sp. nov. differs from all the members of the genus by its more deeply cut sinuation at the junction of the labral margin with the body whorl. The sinulus-like deep grove and the characteristically inward bent labral fold clearly distinguish the species from its congeners. From C. pseudocolchis sp. nov. it can be distinguished mainly by shallower and narrower sinulus-like cut at the posterior canal, by the differently curved columellar peristome, different sinuation of the labral margin and by proportionally larger body whorl.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1F98E04660265385A465B8ED3A38FFBF.taxon	description	Description. Shell: conical, elevated 1.35 - 1.80 mm high shell with 41 / 2 inflated whorls and a deeply cut suture. Shell colour milky white with frequent reddish-brown inorganic encrustations. Umbilicus widely open. The expanded, rhomboidal aperture with a characteristic deep and broad sinus-like cut at the adapical labral junction with the body whorl. The protruded labral fold characteristically curved inward, continuing to a negative sinuation at the lower extremity of the aperture. Columellar margin just slightly positively sinuated. Protoconch surface regularly pitted. Operculum: white, glassy translucent, circular and paucispiral with excentric nucleus. Animal body: entirely white, without eyes and bears, very long tiny tentacles (Plate 12 (5 - 8 )). Holotype measurements: H- 1.80 mm; W- 1.40 mm; BH- 1.15 mm; BW- 1.10 mm; AH- 0.85 mm; AW- 0.65 mm; CA: 37 °. Anatomy: not known.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1F98E04660265385A465B8ED3A38FFBF.taxon	etymology	Etymology. Named after the ancient kingdom Colchis (კოლხეთი) established in the territory of the southwestern Caucasus and the Colchis lowland from the 13 th century BC to 164 BC.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1F98E04660265385A465B8ED3A38FFBF.taxon	distribution	Distribution. Except the type locality and the Motena Cave, the species is known from one locality in the Turchu Gamosadivari basin.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
9261A6B3F3C551128E975D055C59F644.taxon	materials_examined	Other material. Georgia • Samegrelo, Shurubumu Spring (შურუბუმუს წყარო) on the left bank of Khobistskali River; 42 ° 39 ' 0 " N, 42 ° 12 ' 21 " E; 310 m a. s. l.; 10 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-HYD 2 / 5 dry, SBMNH 633085 / 1, NHMW 113364 / 1 dry, coll. JG F 0988 / 4 dry. • Samegrelo, Mapeli Cave (მაპელის მღვიმე), Mukhuri, water catchment (above cemetery); 42 ° 38 ' 22 " N, 42 ° 11 ' 39 " E; 325 m a. s. l.; 12 October 2019; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-HYD 3 / 4 dry, coll. JG F 1411 / 5 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
9261A6B3F3C551128E975D055C59F644.taxon	diagnosis	Diagnosis. The new species differs from the other representatives of the genus by the aperture with a characteristic positive labral and negative columellar sinuations and pyramidal-triangular shell shape. From C. ignidona sp. nov. it can be distinguished by the different form of the aperture and its larger, more robust shell shape. Caucasogeyeria colchis sp. nov. has a more deeply cut labral sinuation at its junction with the body whorl (posterior canal), more inward reflexed mid-labral section and more elevated conical spire. Caucasogeyeria chrysomallos sp. nov. has a similar lateral labral profile, but the shell is significantly smaller with a more narrow-elongate conical shape with a sharper apex. The two species from Abkhazia (C. valvataeformis and C. horatiaeformis) differ in shell shape and lack sinuated labral and columellar margins.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
9261A6B3F3C551128E975D055C59F644.taxon	description	Description. Shell: conically shaped with 31 / 2 inflated whorls and blunt apex, height 1.40 - 2.08 mm. The body whorl proportionally large and expands slightly towards the aperture. The shell surface milky whitish with dense faint regular axial growth lines, frequently covered by rusty-brown inorganic incrustations. The expanding irregular shaped aperture with a characteristic pronounced sinuation at its labral margin best seen in lateral profile. The sinuation slightly curved inward the aperture. The columellar margin with an inward sinuation. Umbilicus widely open. Protoconch surface smooth with almost invisible smooth pitting. Operculum: translucent glass-whitish, circular, paucispiral with excentric nucleus. Animal body: not pigmented, white coloured, eyeless with proportionally long tentacles. Holotype measurements: H- 1.40 mm; W- 1.29 mm; BH- 1.06 mm; BW- 1.00 mm; AH- 0.80 mm; AW- 0.70 mm; CA: 26 °. Anatomy: not known.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
9261A6B3F3C551128E975D055C59F644.taxon	etymology	Etymology. Named after the renowned German malacologist Peter Gloeer from Hetlingen (Germany), who contributed much to the study of Eurasian freshwater Mollusca as well as the knowledge of Ponto-Caspian freshwater biodiversity.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
9261A6B3F3C551128E975D055C59F644.taxon	distribution	Distribution. Caucasogeyeria gloeri sp. nov. is known from the eastern range of limestone Pakhe Plateau from Kinchkhaperdi to Satsiskvilo and in all springs of the Turchu Gamosadivari Basin in Imereti region. The isolated population from Shurubumu Spring and Mapeli Cave at Mukhuri (C. cf. gloeri), Samegrelo region (Plates 13 (3), 14 (4) and 16 (9 )) could represent a geographical subspecies or a distinct species.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
A902B762A52C56AD92E2262D1D0542A8.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 02 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 003 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 003 - P 1 / 170 dry, SBMNH 633095 / 11 dry, NHMW 113363 / 2 dry, HNHM 104677 / 2 dry, NHMUK 20191333 / 2 dry, NHMB 563963 / 2 dry, SMF 358924 / 2 dry, ZMH 140629 / 2 dry, MNHN-IM- 2016 - 7894, ZIN 1 / 506 - 2020 / 2 dry, coll. JG F 0990 / 170 dry, coll. Gloeer / 1 dry. Other material: Georgia • Imereti, Nakhriduri 2 left tributary spring at Turchu Gamosadivari Basin; 42 ° 28 ' 39 " N, 42 ° 30 ' 43 " E; 870 m a. s. l.; 03 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG / 12 dry. • Imereti, Turchusmtha, Okatse Spring above Kinchkha waterfall; 42 ° 29 ' 49 " N, 42 ° 32 ' 49 " E; 1050 m a. s. l.; 02 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG / 19 dry. • Imereti, Nakhriduri, Turchu Gamosadivari Cave Spring; 42 ° 29 ' 13 " N, 42 ° 31 ' 20 " E; 954 m a. s. l.; 03 May 2018; E J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG / 4 dry. • Imereti, Nakhriduri left side tributary spring at Turchu Gamosadivari Basin above small ford; 42 ° 28 ' 39 " N, 42 ° 30 ' 43 " E; 875 m a. s. l.; 03 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG / 27 dry. • Imereti, Upskhero (უფსკერო) Spring Lake at Turchu Gamosadivari Basin; 42 ° 27 ' 47 " N, 42 ° 30 ' 3 " E; 960 m a. s. l.; 03 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG / 3 dry. • Imereti, Nakhriduri 1 at bottom of Turchu Gamosadivari Basin near farm house; 42 ° 28 ' 27 " N, 42 ° 30 ' 13 " E; 860 m a. s. l.; 03 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG / 2 dry. • Imereti, Nakhriduri 3 spring at Turchu Gamosadivari Basin left tributary spring; 42 ° 28 ' 40 " N, 42 ° 30 ' 46 " E; 875 m a. s. l.; 03 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG / 23 dry. • Imereti, Nakhiduri 2 left side spring above small ford; 42 ° 28 ' 39 " N, 42 ° 30 ' 43 " E; 870 m a. s. l.; 03 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG / dry. Georgia • Samegrelo, Pirveli Balda (პირველი ბალდა), spring in village above road; 42 ° 29 ' 2 " N, 42 ° 23 ' 53 " E; 300 m a. s. l. • Samegrelo, Pirveli Balda, Motena Cave; 42 ° 28 ' 36 " N, 42 ° 23 ' 29 " E; 480 m a. s. l.; 09 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. ISU FM-HYD 2 / 2 dry and JG / 3 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
901A57E20B8D5DD194CC7BA4E80B9BE9.taxon	diagnosis	Diagnosis. The genus is well-separable from all other genera of the region by its conspicuously and deeply sinuated labral and columellar margins. The genus Imeretiopsis gen. nov., has much weaker and morphologically different labral sinuation, and the type species of the genus Kartvelobia gen. nov. has a very differently curled labral margin. The penis simple, long and narrow, different than in the genera mentioned above.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
901A57E20B8D5DD194CC7BA4E80B9BE9.taxon	etymology	Etymology. The prefix of the new species Caucaso - is derived from the distribution range of genus in the Caucasus Mountains, and the suffix - geyeria indicating the invalid genus " Geyeria ", previously applied for the genus by Starobogatov (1962). The genus name " Geyeria " was originally dedicated to the famous German malacologist David Geyer (6 November 1855 - 6 November 1932), who contributed greatly to the documentation of the German malacofauna. It was introduced by A. J. Wagner (1914) for the species " Geyeria " plagiostoma from the Bosna River springs near Sarajevo. However, the genus name proved permanently invalid due to junior homonymy, as it had been previously used by Buchecker in 1876 to name a moth in the family Castniidae Boisduval, 1828, Buckman 1899 for a cephalopod, Carapezzae and Schopen 1899 for a brachiopod, and Fucini 1901 for a cephalopod. Based on the homonymy, Tomlin in 1930 renamed the genus to Plagigeyeria. Later Starobogatov (1962) erroneously applied the invalid genus name to two stygobiotic species from the southwestern Caucasus (" Geyeria " valvataeformis and " G. " horatieformis). The gender is feminine.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
901A57E20B8D5DD194CC7BA4E80B9BE9.taxon	distribution	Distribution. The genus is distributed on the Pakhe Plateau (situated S of Askhi Plateau) and in springs emerging around its slopes as well as at spring emerging from limestone massif north of Mukhuri settlement (Fig. 13).	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
16F422A81C675FFF9B361C753D667574.taxon	materials_examined	Material. Holotype: Georgia • adult, dry; type locality; 01 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 005 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 005 - P 1 / 1 dry and 1 wet, coll. JG F 0969 / 1 dry and 2 wet.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
16F422A81C675FFF9B361C753D667574.taxon	diagnosis	Diagnosis. The new species can be distinguished from other members of the genus by the typical shell aperture. Caucasogeyeria gloeri sp. nov. has a larger, more robust shell with different aperture, C. colchis sp. nov. has more sinuated and more deeply cut labral margin at its columellar side, and C. chrysomallos sp. nov. has smaller, more conical and elongate shell with a greater number of whorls and proportionally smaller, differently shaped aperture.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
16F422A81C675FFF9B361C753D667574.taxon	description	Description. Shell: conical with blunt protoconch and with 31 / 2 inflated whorls separated by semi-deep suture. Height 1.4 - 1.7 mm. Shell surface milky white, glossy with occasional rusty brown incrustations. Aperture expanded, proportionally larger, rhomboidal with a weak negative sinuation at labral junction with the body whorl and a weak positive sinuation at columellar margin. Umbilicus slit-like. Operculum: paucispiral, glass-like translucent. Animal body: white, without eye spots. Holotype measurements: H- 1.60 mm; W- 1.10 mm; BH- 1.15 mm; BW- 0.9 mm; AH- 0.85 mm; AW- 0.70 mm; CA: 28 °. Anatomy: the penis (Fig. 14 A-C) bent, simple, narrow, gradually narrowing towards its distal end, vas deferens inside running straight.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
16F422A81C675FFF9B361C753D667574.taxon	etymology	Etymology. Name derived from Latin word ignidona meaning of " donating fire ", referring to the gift of Prometheus to the mankind, indirectly indicating the name of type locality in the Prometheus Cave near Kutaisi.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
16F422A81C675FFF9B361C753D667574.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2939812818C65456B1045F97E563E178.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 10 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 006 - H. Paratypes: Georgia • same as for holotype; coll. JG F 1057 / 2 dry. • same as preceding; 10 October 2019; J. Grego, L. Mumladze and G. Bananashvili leg.; ISU FM-T 006 - P 1 / 5 dry, SBMNH 635902 / 1 dry, coll. JG F 1420 / 9 dry. • Samegrelo, Mukhuri, Shurubumu 1 Spring on left bank of Khobistskali River; 42 ° 39 ' 0 " N, 42 ° 12 ' 21 " E; 310 m a. s. l.; sediment at outlet; 10 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. JG F 1057 / 2 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2939812818C65456B1045F97E563E178.taxon	diagnosis	Diagnosis. Caucasogeyeria pseudocolchis sp. nov. differs from all the members of the genus by its more deeply cut and broader sinuation at the posterior canal, at the junction of the labral margin with the body whorl. The larger sinulus-like deep grove and the characteristically unbent labral fold with a different aperture shape clearly distinguish the species from the closely related C. colchis sp. nov.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2939812818C65456B1045F97E563E178.taxon	description	Description. Shell: pyramidal with four inflated whorls, deeply cut suture and proportionally larger body whorl. Height 1.32 - 1.55 mm. The milky white shell with occasionally reddish brown inorganic encrustation. Umbilicus widely open. The expanded, rhomboidal aperture framed by a very deep and very broad cut at the posterior canal. The protruded labral fold straight, not curved inward. Labrum continues smoothly toward the lower extremity. Columellar margin is more or less straight. Protoconch surface with large regular deep pits. Operculum: not known. Animal body: not known. Holotype measurements: H- 1.45 mm; W- 1.15 mm; BH- 1.25 mm; BW- 0.95 mm; AH- 0.70 mm; AW- 0.60 mm; CA: 28 °. Anatomy: not known.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2939812818C65456B1045F97E563E178.taxon	etymology	Etymology. Named after the very similar shell shape to the C. colchis sp. nov. known from the Pakhe Plateau near Pirveli Balda and Nakhriduri.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2939812818C65456B1045F97E563E178.taxon	distribution	Distribution. Known only from the type locality at Shurubumu Spring and from Shisha Spring in the vicinity of Mukhuri.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
EABB3069FDEB53A9B563889CED093209.taxon	materials_examined	Other material. Georgia • Samegrelo, Pirveli Balda, Motena Cave; 42 ° 28 ' 36 " N, 42 ° 23 ' 29 " E; 480 m a. s. l.; 09 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; coll. ISU FM-HYD 1 / 2 dry and JG / 3 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
EABB3069FDEB53A9B563889CED093209.taxon	diagnosis	Diagnosis. The new species shows some similarity to the geographically isolated C. olsavskyi sp. nov. from Nazodelavo Cave near Chkhorotsku, but it differs by its by its more oval, elongate shells shape with proportionally larger body whorl, by larger and differently positioned aperture situated more left of the columella (to viewer; shell in apertural pose, apex up) and by the more closed umbilicus. Measurement comparison of Caucasopsis species is given in Table 6.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
EABB3069FDEB53A9B563889CED093209.taxon	description	Description. Shell: narrow elongate-oval, 1.66 - 2.00 mm high with 41 / 2 slightly tumid whorls, blunt protoconch, and weak suture. Shell surface whitish and smooth with faint axial growth lines, covered by milky white periostracum and by inorganic incrustations. Aperture proportionally smaller vs. the body whorl and more close-set to the columellar axis. The peristome attached to the body whorl by a weak sulcus over approximately a quarter of its outline. Lateral and columellar labral profiles smooth-straight with no traces of any sinuation. Umbilicus closed. Operculum: not known. Animal body: not known. Holotype measurements: H- 2.00 mm; W- 0.91 mm; BH- 1.19 mm; BW- 0.81 mm; AH- 0.64 mm; AW- 0.51 mm; CA: 34 °. Anatomy: not known.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
EABB3069FDEB53A9B563889CED093209.taxon	etymology	Etymology. Named after Egrisi (ეგრისი), the historical name of the Colchis Kingdom established in the region from the 13 th to the 1 st century BC (disestablished in 164 BC).	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
EABB3069FDEB53A9B563889CED093209.taxon	distribution	Distribution. Only known from the type locality; the similar shells can be found in a nearby Motena Cave.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
9BAD2D702C5E5B47A977481EA43A770E.taxon	materials_examined	Material. Holotype: Georgia • 1. Adult, dry; type locality; 09 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 007 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 007 - P 1 / 1 dry, coll. JG F 1031 / 2 dry. • same as for holotype; 13 October 2019; J. Grego leg.; ISU FM- T 007 - P 2 / 2 dry, coll. JG F 1436 / 22 dry SBMNH 639553, HNMB 563965 / 1 dry, NHMW 113367 / 1 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
65E19D736DF65BBC8652527192705777.taxon	diagnosis	Diagnosis. The new genus has a shell shape similar to members of the genus Imeretiopsis gen. nov. from more eastern localities of the Imereti region, which have, in contrast, a sinuated labral lateral profile. However, both genera can be clearly distinguished by their penes (Fig. 11 A, B): the penis is long, with the filament (lacking in Imeretiopsis) and, below the filament, delicately marked outgrowth on the left side (in Imeretiopsis there are two broad outgrowths).	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
65E19D736DF65BBC8652527192705777.taxon	etymology	Etymology. The name derived from the prefix Caucas - referring to the distribution range in the Caucasus Mountains and suffix - opsis reminiscent of the previously applied genus Paladilhiopsis Pavlovic, 1913, adopted by Starobogatov (1962) for the similar shelled species from Abkhazia and from the Sochi region (Russia). Its gender is feminine.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
65E19D736DF65BBC8652527192705777.taxon	distribution	Distribution. The new genus Caucasopsis is known from the Samegrelo region, and likely from the Abkhazia and Sochi regions in the Russian Federation (Fig. 10).	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
A0611C73417855B1B421BABB742B6350.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 10 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 010 - H Paratypes: same as for holotype; ISU FM-T 010 - P 1 / 80 dry, SBMNH 633077 / 5 dry, NHMW 113368 / 2 dry, HNHM 104679 / 2 dry, NHMUK 0191335 / 2 dry, NHMB 563966 / 2 dry, SMF 358926 / 2 dry, ZMH 140631 / 2 dry, MNHN-IM- 2016 - 7896, ZIN 1 / 510 - 2020 / 2 dry, coll. JG F 1045 / 80 dry, coll. Gloeer / 1 dry. Other material: Georgia • Samegrelo, Chkhorotsku, Kachara Cave (ქაჩარას მღვიმე); 42 ° 31 ' 47 " N, 42 ° 10 ' 39 " E; 205 m a. s. l.; sandy sediment at cave stream; 10 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM / 6 dry and 7 wet, SBMNH 633080, coll. JG F 1051 / 6 dry and 8 wet. Georgia • Samegrelo, Chkhorotsku, Garakha, Savekuo Cavern; 42 ° 30 ' 23 " N, 42 ° 08 ' 46 " E; 240 m a. s. l.; mud sediments in the spring pond; 12 June 2019; H. Reip leg.; coll. F. Walther / 58, coll. J. Grego / 3 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
A0611C73417855B1B421BABB742B6350.taxon	diagnosis	Diagnosis. Caucasopsis letsurtsume sp. nov. differs from its closest relatives by its elongate-oval shell with inflated whorls and open umbilicus with aperture situated more right of the columellar axis (to viewer; shell in apertural pose, apex up). Caucasopsis letsurtsume sp. nov. has a more robust shell with proportionally larger body whorl, smaller umbilicus and with different protoconch surface. Caucasopsis olsavskyi sp. nov. can be differentiated by its different shell shape, closed umbilicus and proportionally smaller aperture situated adjacent to the columellar axis. The shell of C. egrisi sp. nov. is more slender with less inflated whorls and more closed umbilicus. Its shell morphology also resembles Imeretiopsis nakeralaensis sp. nov., which has a more elongate shell, more open umbilicus, less inflated whorls and a proportionally smaller rounded aperture situated more left of the columella (to viewer; shell in apertural pose, apex up).	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
A0611C73417855B1B421BABB742B6350.taxon	description	Description. Shell: elongate-oval, 1.64 mm high with blunt apex, inflated, 41 / 2 whorls and deep suture. Shell surface smooth, glossy with very faint growth lines. Umbilicus narrow, slit-like. Aperture ovoid in shape, attached to the body whorl only shortly by an indistinct groove. Lateral and columellar profiles of the aperture straight. Lateral profile of the body whorl slightly expanding. Protoconch densely pitted. Operculum: paucispiral yellowish, horny elongate ellipsoid with excentric nucleus. Animal body: not known. Holotype measurements: H- 1.64 mm; W- 0.94 mm; BH- 0.89 mm; BW- 0.72 mm; AH- 0.60 mm; AW- 0.47 mm; CA: 34 °. Anatomy: the penis (Fig. 11 A, B) simple, straight, proximally and medially broad, distally with a moderately long, narrow filament; below the filament a delicately marked outgrowth on the left side.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
A0611C73417855B1B421BABB742B6350.taxon	etymology	Etymology. Name derived from the name of Letsurtsume Cave, the type locality of the species.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
A0611C73417855B1B421BABB742B6350.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
204FCF065FC851CBBF6D2424D500690E.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 11 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 009 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 009 - P 1 / dry, NHMW 113369 / 1 dry, coll. JG F 1053 / 2 dry, coll. Gloeer / 1 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
204FCF065FC851CBBF6D2424D500690E.taxon	diagnosis	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.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
204FCF065FC851CBBF6D2424D500690E.taxon	description	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.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
204FCF065FC851CBBF6D2424D500690E.taxon	etymology	Etymology. Named for our friend Mario Olsavsky, geologist and speleologist from Banska Bystrica, Slovakia, who actively participated in the field trip to Georgia.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
204FCF065FC851CBBF6D2424D500690E.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
B16AB4C717385FC284D28FBC76A2DDC8.taxon	diagnosis	Diagnosis. The new genus differs from Pontohoratia Vinarski, Palatov & Gloeer, 2014 by its flatter shell shape, more coarsely pitted protoconch and by its operculum with a distinct peg on its inner side. The molecular data support the closest relationship is to the genus Kartvelobia gen. nov.; however, its valviform shell shape is substantially different from the elongate oval shape and aperture morphology of its relative.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
B16AB4C717385FC284D28FBC76A2DDC8.taxon	etymology	Etymology. Name derived from Bernhard Hausdorf, Hamburg University (Germany), who contributed much to the study of Mollusca from whole Caucasus region.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
B16AB4C717385FC284D28FBC76A2DDC8.taxon	distribution	Distribution. Known from the karstic plateau of Shaori (შაორის კარსტული პლატო) and adjacent stygobiotic habitats (Fig. 15).	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2871C1CA50B85997AACBC79D9DB809F6.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality. 07 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 011 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 011 - P 1 / 41 dry, SBMNH 633086 / 5 dry, NHMW 113370 / 1 dry, HNHM 104680 / 1 dry, NHMUK 20191336 / 1 dry, NHMB 563967 / 2 dry, SMF 358927 / 1 dry, ZMH 140632 / 1 dry, MNHN-IM- 2016 - 7897, ZIN 1 / 512 - 2020 / 1 dry, coll. JG F 1025 / 41 dry, Gloeer / 1 dry; • same as preceding; 13 October 2019; J. Grego, L. Mumladze and G. Bananashvili leg.; ISU FM-T 011 - P 2 / 19 dry, coll. JG F 1426 / 19 dry. Other material: Georgia • Racha, Kveda Tlughi, Kidobana Cave (კიდობანას მღვიმე); 42 ° 26 ' 1 " N, 43 ° 8 ' 45 " E; 1190 m a. s. l.; 07 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg. • Racha, Kveda Tlughi, Cholaburi karst spring; 42 ° 26 ' 8 " N, 43 ° 08 ' 58 " E; 1175 m a. s. l.; 07 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg. • Racha, Skhartali, Sakishore Cave (საკიშორეს მღვიმე); 42 ° 26 ' 32 " N, 43 ° 09 ' 30 " E; 1160 m a. s. l.; 07 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg. • Racha, Velevi, Dolabistavi Cave (დოლაბისთავის მღვიმე); 42 ° 27 ' 05 " N, 43 ° 10 ' 39 " E; 1170 m a. s. l.; 07 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2871C1CA50B85997AACBC79D9DB809F6.taxon	diagnosis	Diagnosis. Hausdorfenia pseudohauffenia sp. nov. differs from most of the congeners by its flatter shell with elevated embryonal whorls and more backward protruding lower aperture vs. the columellar axis. Only P. shareula sp. nov. has a flatter shell, but its spire is sunken. The reddish operculum with an elevated peg-like structure differentiates the species from all relatives.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2871C1CA50B85997AACBC79D9DB809F6.taxon	description	Description. Shell: very flat paucispiral, 1.46 - 1.73 mm in diameter, discoid with flat or only very slightly elevated apex and widely expanded umbilicus. Descending 31 / 4 whorls separated by deeply depressed sulcus. Shell pale translucent, whitish surface, smooth with very faint axial growth lines. Aperture ovoid and in basal view declined left towards the body whorl, from which separated by a narrow gap. Lateral profile of the aperture is strongly sloped towards the apex. Protoconch with coarsely pitted surface converting adapically into a raised malleated surface. Operculum: circular, with central nucleus, thickening at its central part. Inner side smooth centrally raising to a distinct internal peg at point of attachment to the retractor muscle (Fig. 17). Animal body: without eye spots, milky white coloured with irregular small dispersed dark grey blotches visible through translucent shell. Holotype measurements: H- 0.82 mm; W- 1.68 mm; BH- 0.74 mm; BW- 1.11 mm; AH- 0.53 mm; AW- 0.58 mm; CA: - 48 °. Anatomy: not known.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2871C1CA50B85997AACBC79D9DB809F6.taxon	etymology	Etymology. Name derived from the shell morphology resemblance of the new taxon to the Middle European stygobiotic genus Hauffenia Pollonera, 1899.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2871C1CA50B85997AACBC79D9DB809F6.taxon	distribution	Distribution. Aside from the type locality similar shells or fragments, likely belonging to the same species, were found in the following localities: Kidobana Cave, Cholaba Spring, Shakishore Cave and Dolabistavi Cave in the Shaori Basin.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1C425869E88C5CBFAF75137953446DBA.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 06 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 012 - H. Other material: Georgia • Fragmented shells; Racha, Nikorsminda, Shareula River Head (Shareula Cave); 42 ° 28 ' 12 " N, 43 ° 04 ' 4 " E; 1105 m a. s. l.; date; 20.08.2017, J. Grego leg.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1C425869E88C5CBFAF75137953446DBA.taxon	diagnosis	Diagnosis. The new taxon significantly differs from all congeners by its flat shape with spire hidden in apertural profile and its planorboid coiling, a unique feature within the southwestern Caucasus stygobiotic Gastropoda. Measurement comparison of Pontohoratia and Hausdorfenia species is given in Table 9.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1C425869E88C5CBFAF75137953446DBA.taxon	description	Description. Shell: planispiral, discoid with planorboid (slightly hyperstrophic) coiling and 1.34 mm in diameter. Descending 21 / 4 whorls separated by a deep suture. Umbilicus very widely expanding. Shell colour milky white, surface smooth with very faint axial growth lines. Aperture circular, and its labral periphery is oblique to the columellar axis. It attached to the whole length of the adjacent body whorl by a narrow suture. Protoconch pitted over whole surface. Operculum: not known. Animal body: not known. Holotype measurements: H- 0.53 mm; W- 1.34 mm; BH- 0.50 mm; BW- 0.82 mm; AH- 0.48 mm; AW- 0.42 mm; CA: - 57 °. Anatomy: not known.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1C425869E88C5CBFAF75137953446DBA.taxon	etymology	Etymology. Name derived from the name of the Shareula River (მდინარე შარეულა), left tributary of the Rioni River, in which valley and a nearby tributary the new taxon was found.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1C425869E88C5CBFAF75137953446DBA.taxon	distribution	Distribution. Except the type locality few similar fragments were found at the Shareula River Head (entrance of Shareula Cave).	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
29048650A83252449510B797A1CB57AF.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 01 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 016 - H. Paratypes: Georgia • same as for holotype; 12 October 2019; J. Grego, L. Mumladze and G. Bananashvili leg.; 4 ISU FM-T 016 - P 1 / 1 dry, JG F 1406 / 1 dry, ZIN 1 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
29048650A83252449510B797A1CB57AF.taxon	diagnosis	Diagnosis. The new species differs conspicuously from all the similar species of the region by its more slender shell with more conspicuous axial growth lines, closed umbilicus and narrower aperture. Caucasogeyeria orientalis (Starobogatov, 1962) has a similar, but more robust, oval shell shape with a different shape of the aperture.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
29048650A83252449510B797A1CB57AF.taxon	description	Description. Shell: elongate narrow-turreted, 2.00 - 2.29 mm high shell with 51 / 2 tumid whorls, weak suture and flat blunt apex. The early whorls rather inflated, and the inflation of whorls regularly decreasing abapically, apex almost flat. Shell surface glossy, whitish translucent with faint regularly spaced distant rib-like growth lines. Umbilicus closed. Aperture not expanded, elongate-oval with weakly sinuated labral profile and flat columellar profile. Protoconch pitted. Operculum: light yellow, horny, elongate ellipsoid, paucispiral with excentric nucleus. Animal body: not known. Holotype measurements: H- 2.00 mm; W- 0.81 mm; BH- 0.96 mm; BW- 0.72 mm; AH- 0.62 mm; AW- 0.49 mm; CA: 35 ° Anatomy: not known.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
29048650A83252449510B797A1CB57AF.taxon	etymology	Etymology. Named after Robert A. D. Cameron from Sheffield University, who significantly contributed to the malacological knowledge of Eurasia including Caucasus region.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
29048650A83252449510B797A1CB57AF.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6082F8E275975B299F24A32B5E91899A.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 13 October 2019; J. Grego, L. Mumladze and G. Bananashvili; ISU FM-T 013 - H. Paratypes: same as for holotype; ISU FM-T 013 - P 1 / 49 dry and 83 wet, SBMNH 635910 / 7 dry, NHMW 113279 / 2 dry, HNHM 104681 / 2 dry, NHMUK 20191337 / 2 dry, NHMB 563968 / 2 dry, SMF 358928 / 2 dry, ZMH 140633 / 2 dry, MNHN-IM- 2016 - 7897, ZIN 1 / 509 - 2020 / 2 dry, coll. JG F 1430 / 49 dry and 84 wet.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6082F8E275975B299F24A32B5E91899A.taxon	diagnosis	Diagnosis. The new species differs from all the related species of the region by its more robust shape, more open umbilicus and more expanded rounded aperture. The most similar shell morphology can be seen in I. iazoni sp. nov., however, I. gorgoleti sp. nov. has a much larger and robust shell with a more open umbilicus and more expanded aperture. From the members of the genus Caucasopsis gen. nov. as the C. tsurtsume sp. nov. it differs by its less sinuated labral margin and by a more regular apertural form.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6082F8E275975B299F24A32B5E91899A.taxon	description	Description. Shell: height ranges from 1.52 to 2.18 mm, conical to ovate-conical shell, with 41 / 2 whorls, blunt protoconch, rather inflated whorls and deep suture. Umbilicus widely open. Shell surface glossy, milky-translucent with very faint almost invisible axial growth lines. Aperture subcircular and expanded. Lateral labral profile weakly sinuated adapically toward the body whorl; columellar labrum has a weak sinuation near columella. Protoconch surface densely covered by large regular weak pits. Operculum: translucent, milky whitish, paucispiral with excentric nucleus. Animal body: animal white, eyeless with light brown pellets and randomly spread dark grey diffused fibre-like streaked blotches on mantle visible through the translucent shell from body whorl up to the early whorls. Holotype measurements: H- 2.18 mm; W- 1.44 mm; BH- 1.35 mm; BW- 1.15 mm; AH- 0.94 mm; AW- 0.82 mm; CA: 38 °. Anatomy: the penis (Fig. 11 C) bent, cylindrical, distally with no filament but broadly conical, in its median part a characteristically shaped double outgrowth, proximally broad and distally blunt.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6082F8E275975B299F24A32B5E91899A.taxon	etymology	Etymology. Name derived from Gorgoleti village (Racha region) (სოფელი გორგოლეთ), which is the closest village to the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6082F8E275975B299F24A32B5E91899A.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
934DA6999F065F95888E844AC31383DD.taxon	diagnosis	Diagnosis. The general shell morphology of the new genus is similar to some stygobiotic genera from the Balkans (Paladilhiopsis Pavlovic, 1913; Iglica A. J. Wagner, 1910), Middle Europe (Bythiospeum Bourguignat, 1882) and Southeast Asia (Pseudoiglica Grego, 2018). The main conchological difference distinguishing the new genus from Caucasopsis gen. nov., is the sinuated labral profile. The penis long, without the filament characteristic of Caucasopsis, but with two broad outgrowths on its left side.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
934DA6999F065F95888E844AC31383DD.taxon	etymology	Etymology. Name is derived from the Imereti (იმერეთი) region, where the type locality and the known distribution of the genus are located. The suffix - iopsis refers to the resemblance to the shells of the Balkan genus Paladilhiopsis Pavlovic, 1913. Its gender is feminine.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
934DA6999F065F95888E844AC31383DD.taxon	distribution	Distribution. The genus Imeretiopsis gen. nov. is known from the Imereti and West Racha regions of Georgia (Fig. 10).	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
28ACD3799F4557609D11D2E37785C07B.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; J. Grego, L. Mumladze and G. Bananashvili leg.; ISU FM-T 014 - H. Paratypes: same as for holotype, ISU FM-T 014 - P 1 / 1 dry, coll. JG F 1409 / 1 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
28ACD3799F4557609D11D2E37785C07B.taxon	diagnosis	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.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
28ACD3799F4557609D11D2E37785C07B.taxon	description	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.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
28ACD3799F4557609D11D2E37785C07B.taxon	etymology	Etymology. Named after the type locality, Iazoni Cave (იაზონის მღვიმე) (= Tskal-Tsiteli = Rioni Cave (= წყალწითელას = რიონის მღვიმე )) in Kutaisi.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
28ACD3799F4557609D11D2E37785C07B.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1B2BA0EC1C6452D79A3D1249E5451D1B.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 04 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 015 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 015 - P 1 / 10 dry, SBMNH 633110 / 2 dry, NHMW 113371 / 1 dry, NHMB 563969 / 2 dry, coll. JG F 1009 / 10 dry, coll. Gloeer / 1 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1B2BA0EC1C6452D79A3D1249E5451D1B.taxon	diagnosis	Diagnosis. The new species differs from all the morphotypes with related shell shape in the region by its more robust oval shape, by the position of the aperture more right of the columella (to viewer; shell in apertural pose, apex up), and by the more open umbilicus. Caucasogeyeria shakuranica (Starobogatov, 1962) from Abkhazia has similar but narrower shell shape with less inflated whorls and a proportionally smaller body whorl. Caucasogeyeria letsurtsume sp. nov. has a smaller shell with more inflated whorls and more open umbilicus.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1B2BA0EC1C6452D79A3D1249E5451D1B.taxon	description	Description. Shell: 2 mm high, elongate ovate-conical with pronounced protoconch, five tumid whorls and moderately deep suture. Shell surface whitish, translucent-glossy, covered by faint axial growth lines. Umbilicus open. Proportionally small aperture irregular, almost round, not expanded, with straight lateral and columellar labral profiles lacking sinuation. Protoconch surface densely and coarsely pitted. Operculum: not known. Animal body: not known. Holotype measurements: H- 2.00 mm; W- 1.09 mm; BH- 1.02 mm; BW- 0.85 mm; AH- 0.64 mm; AW- 0.53 mm; CA: 29 °. Anatomy: not known.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1B2BA0EC1C6452D79A3D1249E5451D1B.taxon	etymology	Etymology. Name after the Nakerala Pass 1218 m alt. situated above the type locality north of Tikbuli along the road to Ambrolauri.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
1B2BA0EC1C6452D79A3D1249E5451D1B.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
D5DCFC9B58365627B4FB771A06C5DCE7.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 01 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 017 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 017 - P 1 / 21 dry, SBMNH 633098 / 4 dry, NHMW 113372 / 1 dry, HNHM 104682 / 1 dry, NHMUK 20191338 / 1 dry, NHMB 563970 / 1 dry, SMF 358929 / 1 dry, ZMH 140634 / 1 dry, NHMW 113372 / 1 dry, ZIN 1 / 508 - 2020 / 1 dry, coll. JG F / 21 dry and 2 wet, coll. Gloeer / 1 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
D5DCFC9B58365627B4FB771A06C5DCE7.taxon	diagnosis	Diagnosis. The species differs from all the related morphotypes from the Caucasus by the more conical-elongate shell with typical triangular shell shape, by the more oval aperture situated more right of the columellar axis (to viewer; shell in apertural pose, apex up). I. cameroni sp. nov. has a much narrower elongated shell shape with a more elongated aperture and less inflated whorls with closed umbilicus, and I. nakeralaensis sp. nov. has more robust, oval shell with proportionally smaller aperture and narrower umbilicus.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
D5DCFC9B58365627B4FB771A06C5DCE7.taxon	description	Description. Shell: elongate-conical, 1.42 - 1.66 mm high with five whorls, blunt protoconch, inflated whorls, deep suture and proportionally larger body whorl. Umbilicus narrow, slit like. Shell surface glossy, translucent with horny-yellowish periostracum, occasionally covered by rusty-brown inorganic incrustations. Aperture irregularly ovate, slightly expanded, separated from body whorl by a grove and by broadening adapical apertural gap. Lateral labral profile weakly sinuated, columellar profile straight. Protoconch strongly pitted. Operculum: yellowish, translucent, elongate ellipsoid, paucispiral with excentric nucleus. Animal body: eyeless, milky whitish coloured with light brown pellets. Holotype measurements: H- 1.66 mm; W- 0.53 mm; BH- 0.87 mm; BW- 0.72 mm; AH- 0.60 mm; AW- 0.47 mm; CA: 33 °.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
D5DCFC9B58365627B4FB771A06C5DCE7.taxon	etymology	Etymology. Name is derived from the type locality inside Prometheus Cave (პრომეთეს მღვიმე). The cave was named after Prometheus, the Titan of Greek mythology, who created mankind from clay, stealing the fire from gods and providing it to humanity. As punishment, he was eternally bound to a rock at Caucasus Mountains, where each day an eagle was sent to feed on his liver.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
D5DCFC9B58365627B4FB771A06C5DCE7.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2A1F599698F75C50BEBF74AE850C81A3.taxon	materials_examined	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. Olsavsky 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. Olsavsky leg. • same as preceding; 13 October 2019; J. Grego leg.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2A1F599698F75C50BEBF74AE850C81A3.taxon	diagnosis	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.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2A1F599698F75C50BEBF74AE850C81A3.taxon	description	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. 9 A-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. 9 E) with a short and broad oviduct loop, small distal receptaculum seminis (at the position of rs 1 of Radoman: see Szarowska (2006)) and big spherical bursa copulatrix with a long duct.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2A1F599698F75C50BEBF74AE850C81A3.taxon	etymology	Etymology. Named after the conspicuously sinuated labral margin.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
2A1F599698F75C50BEBF74AE850C81A3.taxon	distribution	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.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
0BF8373340C25EE4B298C7FBCA54668B.taxon	diagnosis	Diagnosis. The new genus differs from all known stygobiotic Hydrobiidae and Moitessieriidae by general shell shape with characteristically deeply sinuated labral margin; however, the smaller representatives of the genus can possess only very weak labral sinuation while still having elongate-oval shells with inflated whorls and aperture slightly detached from the body whorl.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
0BF8373340C25EE4B298C7FBCA54668B.taxon	etymology	Etymology. Name derived from the name of Georgia in local language Sakartevelo (საქართველო), which is frequently used in its short vocative form as Kartvelo (ქართველო). Its gender is feminine.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
0BF8373340C25EE4B298C7FBCA54668B.taxon	distribution	Distribution. The new genus is known from western Imereti region, where it can be found in springs and caves in the Turchu Gamosadivari basin and around the karstic Pakhe Plateau. In the Samegrelo region it is distributed in springs and caves on the eastern slope of Pakhe Plateau and from the springs around Mukhuri village (Fig. 8).	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
4705966665545CD29DB4A566EE90E5FA.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 02 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 018 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 018 - P 1 / 1 dry, SBMNH 633106 / 1 dry, coll. JG F 0987 / 1 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
4705966665545CD29DB4A566EE90E5FA.taxon	diagnosis	Diagnosis. The new species differs from Kartvelobia sinuata sp. nov. by its less weakly-sinuated labral margin without tooth-like folds, by smaller shell size, smooth protoconch surface and the different shape of the aperture. From the similar sized K. shishaensis sp. nov. it differs by its more smoothly sinuated labral margin, by proportionally larger body whorl, by smoother protoconch surface and by more inflated whorls.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
4705966665545CD29DB4A566EE90E5FA.taxon	description	Description. Shell: the minute shell (1.29 - 1.32 mm high) with 31 / 2 whorls and a blunt apex, with elongate-oval shape, inflated whorls, weak suture and closed umbilicus. Shell surface smooth to glossy, whitish translucent. The aperture of an irregular tear-shaped with pronounced upper-right tip and separated from the body whorl by a deep groove. The lateral profile of labral margin characteristically weakly sinuated and anteriorly elongated. The labral columellar profile almost straight, only slightly curved. Protoconch with a smooth surface. Operculum: not known. Animal body: not known. Holotype measurements: H- 1.32 mm; W- 0.71 mm; BH- 0.95 mm; BW- 0.62 mm; AH- 0.58 mm; AW- 0.52 mm; CA: 45 °. Anatomy: not known.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
4705966665545CD29DB4A566EE90E5FA.taxon	etymology	Etymology. Name derived from the tallest Georgian waterfall Kinchkha (კინჩხას ჩანჩქერი) near Kinchkhaperdi. Type locality is situated between the two lower cascades of the waterfall.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
4705966665545CD29DB4A566EE90E5FA.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
A372AE2D1BD95AFC9B3BC9240F13178B.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 42 ° 37 ' 47 " N, 42 ° 11 ' 26 " E; 250 m a. s. l.; 10 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 019 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 019 - P 1 / 3 dry, SBMNH 633084 / 2 dry, coll. JG F 1043 / 3 dry; • same as for holotype; 12 October; 2019; J. Grego, L. Mumladze and G. Bananashvili leg.; NHMW 113373 ISU-T 019 - P 2 / 4 dry, coll JG F 1056 / 4 dry; Georgia • Samegrelo, Mukhuri, Mapeli Cave (მაპელის მღვიმე); 42 ° 38 ' 22 " N, 42 ° 11 ' 39 " E; 330 m a. s. l.; 12 October 2019; J. Grego, L. Mumladze and G. Bananashvili leg.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
A372AE2D1BD95AFC9B3BC9240F13178B.taxon	diagnosis	Diagnosis. The new species differs from the Kartvelobia sinuata sp. nov. by its very weakly sinuated almost straight labral margin, minute shell size, more pitted protoconch and different shape of the aperture. From the similar sized K. kinchkha sp. nov. differs by its less sinuated labral margin, by less inflated whorls and by the pitted protoconch surface. Measurement comparison of Kartvelobia species is given in Table 4.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
A372AE2D1BD95AFC9B3BC9240F13178B.taxon	description	Description. Shell: minute, 1.32 - 1.45 mm high, elongated-oval shell with four whorls, semi-blunt apex and smooth whitish glossy surface; slightly inflated whorls separated by weak suture. Aperture irregularly tear-shaped, slightly expanded and detached from the body whorls by a distant grove or gap. Lateral profile of labral margin almost straight with very inconspicuous sinuation; columellar labral profile straight. Protoconch surface pitted. Operculum: not known. Animal body: not known. Holotype measurements: H- 1.45 mm; W- 0.74 mm; BH- 1.02 mm; BW- 0.62 mm; AH- 0.55 mm; AW- 0.58 mm; CA: 51 °. Anatomy: not known.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
A372AE2D1BD95AFC9B3BC9240F13178B.taxon	etymology	Etymology. Name after the type locality: the karst spring Shisha at southeast end of village Mukhuri.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
A372AE2D1BD95AFC9B3BC9240F13178B.taxon	distribution	Distribution. Only known from the type locality and from nearby Mapeli Cave in Mukhuri.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
E0FF0A3480B75B4EA2C563FDA068149B.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 02 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 020 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 020 - P 1 / 500 dry specimens, SBMNH 633041 / 7 dry, NHMW 113374 / 10 dry, HNHM 104683 / 10 dry, NHMUK 20191339 / 10 dry, NHMB 563971 / 10 dry, SMF 358930 / 10 dry, ZMH 140635 / 10 dry, MNHN-IM- 2016 - 7894, ZIN 1 / 511 - 2020 / 10 dry, coll. JG F 0989 / 500 dry, coll. Gloeer / 2 dry; Other material: Georgia • Imereti, Nakhriduri, Turchu Gamosadivari Cave; 42 ° 29 ' 13 " N, 42 ° 31 ' 20 " E; 951 m a. s. l.; 03 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg., JG / 3 dry. • Imereti, Nakhriduri 3 spring at Turchu Gamosadivari Basin left side; 42 ° 28 ' 41 " N, 42 ° 30 ' 45 " E; 860 m a. s. l.; 03 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg. JG / 5 dry. • Imereti, Nakhriduri 2, Turchu Gamosadivari Basin left side spring above small ford; 42 ° 28 ' 39 " N, 42 ° 30 43 " E; 860 m a. s. l.; 03 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg., JG / 6 dry. • Imereti, Kinchkhaperdi (კინჩხაფერდი), spring right along the road to Askhi Plateau; 42 ° 30 ' 7 " N, 42 ° 33 ' 34 " E; 880 m a. s. l.; 02 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg. JG / 3 dry. • Imereti, Upskhero Spring Lake (უფსკერო ტბა) at Turchu Gamosadivari Basin; 42 ° 27 ' 47 " N, 42 ° 30 ' 3 " E; 890 m a. s. l.; 03 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg. JG / 6 dry. • Imereti, Turchusmtha, spring of Okatse above Kinchkha waterfall; 42 ° 29 ' 49 " N, 42 ° 32 ' 49 " E; 1050 m a. s. l.; 02 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg. JG / 5 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6F29FFEA9D675B2CAAA738CE7D741348.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 06 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 021 - H. Paratypes: Georgia • same as for holotype; col. JG F 1060 / 5 dry; • same as preceding; 12 October 2019; J. Grego, L. Mumladze and G. Bananashvili leg.; ISU FM-T 021 - P 1 / 40 dry and 69 wet, SBMNH 635896 / 6 dry, NHMW 113375 / 2 dry, HNHM 104684 / 2 dry, NHMUK 20191340 / 2 dry, NHMB 563972 / 2 dry, SMF 358931 / 2 dry, ZMH 140636 / 2 dry, MNHN-IM- 2016 - 7900, ZIN 1 / 503 - 2020 / 2 dry, coll. JG F 1413 / 40 dry and 69 wet, coll Gloeer / 1 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6F29FFEA9D675B2CAAA738CE7D741348.taxon	diagnosis	Diagnosis. The shell of the new species is more flat-discoid with a more open umbilicus, more rounded and proportionally smaller aperture vs. the geographically closest relatives: P. vinarskii sp. nov. and P. pichkhaiai sp. nov. The shell shape is somewhat similar to H. pseudohauffenia, but it can be differentiated by less pronounced protoconch, lower shell height to width ratio the proportionally smaller, more rounded aperture as well by its operculum lacking the knobby sculpture.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6F29FFEA9D675B2CAAA738CE7D741348.taxon	description	Description. Shell: small, paucispiral, discoid with flat, only slightly pronounced spire and widely opened umbilicus. Diameter 1.37 - 1.51 mm. The inflated whorls are separated by a deeply cut sulcus. Protoconch surface covered by dense shallow pits. The shell surface whitish and translucent with smooth surface. The aperture round with labral peristome oblique to the columellar axis. The aperture barely attached at its upper columellar side to the body whorl. Protoconch surface covered by raised malleations gradually changing to a regular pitting towards the nucleus. Operculum: reddish, circular, paucispiral with central nucleus, centrally thickened and elevated inward without peg. Holotype measurements: H- 0.57 mm; W- 1.38 mm; BH- 0.55 mm; BW- 0.95 mm; AH- 0.42 mm; AW- 0.45 mm; CA: - 40 °. Anatomy: the penis (Fig. 16 E, F) proximally broad, with a broad, slightly marked outgrowth on its left side in the median part, and thin filament distally.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6F29FFEA9D675B2CAAA738CE7D741348.taxon	etymology	Etymology. Name derived from the name of Mapeli (მაპელი) Spring in Kanti (კანტი) Village, the type locality of the species.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
6F29FFEA9D675B2CAAA738CE7D741348.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
26D3ABD365C057FE97F649AD0323134E.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 10 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 022 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 022 - P 1 / 9 dry, coll. JG F 1044 / 9 dry; • same as for holotype; 11 October 2019; J. Grego, L. Mumladze and G. Bananashvili leg.; ISU FM-T 022 - P 2 / 13 dry SBMNH 633083 / 1 dry, NHMW 113376 / 1 dry, HNHM 104685 / 1 dry, NHMB 563973 / 1 dry, SMF 358933 / 1 dry, ZMH 140637 / 1 dry, MNHN-IM- 2016 - 7901, ZIN 1 / 504 - 2020 / 1 dry, coll. JG F 1419 / 14 fry, coll. Gloeer / 1 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
26D3ABD365C057FE97F649AD0323134E.taxon	diagnosis	Diagnosis. The new species differs from the geographically close P. vinarskii sp. nov. by its flatter shell and smaller, more rounded aperture. P. mapeli has a flatter shell with smaller, more rounded aperture.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
26D3ABD365C057FE97F649AD0323134E.taxon	description	Description. Shell: planispiral small, discoid, the spire only a slightly pronounced and early whorls flat, umbilicus widely opened and protoconch surface pitted. Diameter 1.36 - 1.68 mm. The descending whorls separated by a deep suture. The shell wall is translucent, the surface whitish and smooth. The aperture proportionally small and circular with the labral peristome angled vs. the columellar axis. The aperture in a short distance joining the body whorl. Protoconch surface weakly pitted in its nuclear portion and abapically gradually changing into a smooth slightly malleated surface. Operculum: reddish, circular, paucispiral, with central nucleus and smooth central callosity without forming a peg at its attachment. Holotype measurements: H- 0.87 mm; W- 1.42 mm; BH- 0.66 mm; BW- 1.00 mm; AH- 0.50 mm; AW- 0.5 mm; CA: - 45 °. Anatomy: the penis (Fig. 16 C, D) simple, without any outgrowths, broad, slowly narrowing to its distal end.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
26D3ABD365C057FE97F649AD0323134E.taxon	etymology	Etymology. Named after the avid speleologist Igor Pichkhaia (იგორ ფიჩხაია) from Chkhorotsku, who supported our research in the region of Samegrelo (Mingrelia).	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
26D3ABD365C057FE97F649AD0323134E.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
FDA37D44903B56A5BAE425C982C06ADE.taxon	distribution	Distribution. The genus is known from Samegrelo region around Mukhuri and from Abkhazia in the vicinity of Sukhumi (Fig. 15).	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
5F0459E14BC65E6AACA4D9890AC9584A.taxon	materials_examined	Material. Holotype: Georgia • 1 adult, dry; type locality; 02 May 2018; J. Grego, L. Mumladze and M. Olsavsky leg.; ISU FM-T 023 - H. Paratypes: Georgia • same as for holotype; ISU FM-T 023 - P 1 / 350 dry and 18 wet, P 2 / 10 dry, SBMNH 633077 / 5 dry, NHMW 113377 / 3 dry, HNHM 104686 / 3 dry, NHMUK 20191341 / 3 dry, NHMB 563974 / 3 dry, SMF 358934 / 3 dry, ZMH 140638 / 3 dry, MNHN-IM- 2016 - 7902, ZIN 1 / 505 - 2020 / 3 dry, coll. JG F 1046 / 350 dry and 18 wet, JG F 1047 / 10 dry, coll. Gloeer / 1 dry. Other material: Georgia • Samegrelo, Chkhorotsku, Garakha, Savekuo Cavern, mud sediments in the spring pond; 42 ° 30 ' 23 " N, 42 ° 08 ' 46 " E; 240 m a. s. l.; 12 June 2019; H. Reip leg.; coll. F. Walther / 243 dry, coll. JG / 20 dry.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
5F0459E14BC65E6AACA4D9890AC9584A.taxon	diagnosis	Diagnosis. The new species differs from P. smyri Vinarski, Palatov & Gloeer, 2014 by its more elevated spire and by a proportionally smaller and more ovate aperture. The geographically close C. pichkhaiai sp. nov. and C. mapeli sp. nov. have similar shells, but both are flatter and have much smaller rounded apertures.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
5F0459E14BC65E6AACA4D9890AC9584A.taxon	description	Description. Shell: flat, discoid with elevated spire and flat apex. Diameter 1.31 - 1.58 mm. Umbilicus widely opened. The 23 / 4 whorls are separated by a deeply cut sulcus. Shell transparent whitish colour with smooth surface and almost invisible growth lines. Oval aperture with axis declined towards columella. Peristome smooth without any folds. Lateral profile of the labrum is slightly angled towards the body whorl at its upper side, where attached by a narrow furrow. Protoconch surface regularly weakly pitted on the nuclear portion and abapically smooth. Operculum: orange coloured circular, translucent, with central nucleus, thickened at its centre, but without peg on its inner side. Animal body: whitish, not pigmented, eyeless. Holotype measurements: H- 1.08 mm; W- 1.47 mm; BH- 0.87 mm; BW- 1.00 mm; AH- 0.63 mm; AW- 0.55 mm; CA: - 20 °. Anatomy: the penis (Fig. 16 A, B) simple, broad and blunt, without any outgrowth.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
5F0459E14BC65E6AACA4D9890AC9584A.taxon	etymology	Etymology. Named after renowned Russian malacologist Maxim V. Vinarski, Saint-Petersburg State University, Russia, who contributed significantly to Eurasian freshwater Mollusca studies as well as to the study of southwestern Caucasus freshwater Mollusca.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
5F0459E14BC65E6AACA4D9890AC9584A.taxon	distribution	Distribution. Only known from the type locality.	en	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: 1-77, DOI: http://dx.doi.org/10.3897/zookeys.955.51983, URL: http://dx.doi.org/10.3897/zookeys.955.51983
