Unio gontierii Bourguignat, 1856
Bourguignat, 1856. Aménités Malacol. 2: 33, pl. 4, figs. 1-4.

Unio (sec. Lymnium) carneus — Simpson (1900), Simpson (1914)
Unio crassus gontieri — Haas (1940), Haas (1969), Graf (2007), Lopes-Lima et al. (2017)
Unio stevenianus — Zhadin (1965)
Batavusiana (s.s.) musiva gontieri — Stadnichenko (1984)
Unio (Crassunio) crassus gontierii — Falkner (1994)
Crassiana musiva gontieri — Kantor & Sysoev (2005), Kantor et al. (2010)
Unio crassus — IUCN (2014), Araujo et al. (2018)
Unio gontierii — Lopes-Lima et al. (2024), Hou et al. (2024)

Unio colchicus Drouët, 1881
Drouët, 1881. Unionidae Russie: 18.

Unio (s.s.) sieversi var. colchicus — Zhadin (1938)
Unio crassus gontieri — Haas (1940), Haas (1969), Graf (2007)
Unio sieversi var. colchicus — Zhadin (1965)
Crassiana crassa sieversi — Akromovski (1976), Kantor & Sysoev (2005)
Eolymnium (Shadininaia) colchicum — Zatravkin (1983), Zatravkin (1987)
Eolymnium colchicum — Kantor et al. (2010)
Unio (Eolymnium) colchicus — Vinarski & Kantor (2016)
Unio gontierii — Lopes-Lima et al. (2024)

Unio mingrelicus Drouët, 1881
Drouët, 1881. Unionidae Russie: 16.

— Simpson (1914)
Unio (s.s.) mingrelicus — Zhadin (1938)
Unio crassus gontieri — Haas (1940), Haas (1969), Graf (2007)
Unio mingrelicus — Zhadin (1965), Bába (2000), Kantor & Sysoev (2005)
Unio (Limnium) hueti — Biggs (1971)
Batavusiana (s.s.) mingrelica — Zatravkin (1983), Zatravkin (1987)
Batavusiana (s.s.) mingrelicus — Korniushin (1998)
Crassiana mengrelica [sic] — Kantor et al. (2010)
Unio (Crassiana) mengrelicus [sic] — Vinarski & Kantor (2016)
Unio gontierii — Lopes-Lima et al. (2024)

Unio raddei Drouët, 1881
Drouët, 1881. Unionidae Russie: 17.

Unio (s.s.) sieversi var. raddei — Zhadin (1938)
Unio crassus gontieri — Haas (1940), Haas (1969), Graf (2007)
Eolymnium (Shadininaia) raddei — Zatravkin (1983), Zatravkin (1987)
Eolymnium raddei — Kantor et al. (2010)
Unio (Eolymnium) raddei — Vinarski & Kantor (2016)
Unio gontierii — Lopes-Lima et al. (2024)

Unio sieversi Drouët, 1881
Drouët, 1881. Unionidae Russie: 17.

Unio (s.s.) sieversi — Zhadin (1938)
Unio crassus gontieri — Haas (1940), Haas (1969)
Unio sieversi — Zhadin (1965), Bába (2000)
Crassiana crassa sieversi — Akromovski (1976), Kantor & Sysoev (2005), Kantor et al. (2010)
Eolymnium (Shadininaia) byzantinum — Zatravkin (1983), Zatravkin (1987)
Eolymnium (Shadininaia) byzantinus — Korniushin (1998)
Unio (Eolymnium) byzantinus — Vinarski & Kantor (2016)
Unio gontierii — Lopes-Lima et al. (2024)

Unio stepanoffi Drouët, 1881
Drouët, 1881. Unionidae Russie: 15.

— Simpson (1914)
Unio (s.s.) crassus var. stepanovi [sic] — Zhadin (1938)
Unio crassus gontieri — Haas (1940), Haas (1969)
Unio stevenianus — Zhadin (1965)
Unio stepanoffi — Kantor et al. (2010)
Unio gontierii — Lopes-Lima et al. (2024)

Unio stevenianus Drouët, 1881
Krynicki, 1837. Bull. Soc. imp. Nat. Moscou 10(2): 59 [as ‘steveniana’]. [nomen nudum]
‘Krynicki’ Drouët, 1881. Unionidae Russie: 14.
‘Krynicki’ Drouët, 1881. J. de Conch. 29: 24.
Drouët, 1884. Suppl. Unionidae de Serbie: pls. 1-2.

Unio (sec. Lymnium) batavus — Simpson (1900), Simpson (1914)
Unio (s.s.) stevenianus — Zhadin (1938)
Unio crassus gontieri — Haas (1940), Haas (1969)
Unio stevenianus — Zhadin (1965)
Crassiana crassa sieversi — Akromovski (1976), Kantor & Sysoev (2005)
Batavusiana (s.s.) musiva — Zatravkin (1987)
Unio stevenianius [sic] — Bába (2000)
Unio (Crassiana) musivus — Vinarski & Kantor (2016)
Unio gontierii — Lopes-Lima et al. (2024)

Unio raddei var. koutaisiana Kobelt, 1886
Kobelt, 1886. Icon. Land- und Süssw.-Moll. 2: 40, pl. 52, fig. 283.
(intro'd as intra-sp. of Unio raddei Drouët, 1881)

Unio (s.s.) sieversi var. kutaisiana [sic] — Zhadin (1938)
Unio crassus gontieri — Haas (1940), Haas (1969), Graf (2007)
Eolymnium (Shadininaia) kutaisianum [sic] — Zatravkin (1983), Zatravkin (1987)
Eolymnium koutaisianum — Kantor et al. (2010)
Unio (Eolymnium) koutaisiana — Vinarski & Kantor (2016)
Unio gontierii — Lopes-Lima et al. (2024)

Unio gregorii Kobelt, 1912
Kobelt, 1912. Icon. Land- und Süssw.-Moll. 18: 30, pl. 494, fig. 2632.

Unio (s.s.) mingrelicus var. gregorii — Zhadin (1938)
Unio crassus gontieri — Haas (1940), Haas (1969), Graf (2007)
Batavusiana (s.s.) gregorii — Zatravkin (1983), Zatravkin (1987)
Crassiana gregorii — Kantor et al. (2010)
Unio (Crassiana) gregorii — Vinarski & Kantor (2016)
Unio gontierii — Lopes-Lima et al. (2024)

Unio mingrelicus var. sobriewskii Rosén, 1925
Rosén, 1925. Izvest. Donsk. Politek. Instit. Novoch. 9: 8, fig. 2.
(intro'd as intra-sp. of Unio mingrelicus Drouët, 1881)
Type(s): LECTOTYPE ZIN_AN_SSSR_1, [locality unknown].

Batavusiana (s.s.) sobriewskii — Zatravkin (1983), Zatravkin (1987)
Unio crassus gontieri — Graf (2007)
Crassiana sobriewskii — Kantor et al. (2010)
Unio (Crassiana) sobrievskii [sic] — Vinarski & Kantor (2016)
Unio gontierii — Lopes-Lima et al. (2024)

Unio mingrelicus var. stevenianiformis Zhadin, 1938
Zhadin, 1938. Faune USSR Mollusques 4(1): 96, text fig. 28.
(intro'd as intra-sp. of Unio mingrelicus Drouët, 1881)

Unio (s.s.) mingrelicus var. stevenianiformis — Zhadin (1938)
Unio crassus gontieri — Haas (1940), Haas (1969), Graf (2007)
Batavusiana (s.s.) stevenianiformis — Zatravkin (1983)
Batavusiana (s.s.) stevenianiformes [sic] — Zatravkin (1987)
Crassiana stevenianiformis — Kantor et al. (2010)
Unio (Crassiana) stevenianiformis — Vinarski & Kantor (2016)
Unio gontierii — Lopes-Lima et al. (2024)

Crassiana mengrelica Kantor et al., 2010
‘Drouët’ Kantor et al., 2010. Cat. Contin. Moll. Russia: 260.
‘Drouët’ Vinarski & Kantor, 2016. Analyt. Cat. Fr. Brack. Moll. Russia: 26.
(error for Unio mingrelicus Drouët, 1881)

Unio gontierii — Lopes-Lima et al. (2024)

Unio mingrelicus var. sobrievskii Vinarski & Kantor, 2016
‘Rosen’ Vinarski & Kantor, 2016. Analyt. Cat. Fr. Brack. Moll. Russia: 27.
(error for Unio mingrelicus var. sobriewskii Rosén, 1925)

Unio gontierii — Lopes-Lima et al. (2024)