Mollusc species from the Pontocaspian region - an expert opinion list Author Wesselingh, Frank Naturalis Biodiversity Center, Leiden, Netherlands Author Poorten, Jan Johan ter Field Museum of Natural History, Chicago, United States of America Author Kijashko, Pavel Moscow State University, Moscow, Russia Author Albrecht, Christian Justus Liebig University, Giessen, Germany Author Anistratenko, Olga Yu Schmalhausen Instite of Zoology, National Academy of Sciences of Ukraine, Kiev, Ukraine & Institute of Geological Sciences, National Academy of Sciences of Ukraine, KievUkraine Author Frolov, Pavel Saint-Petersburg State University, Saint Petersburg, Russia Author Gándara, Alberto Martinez Grigore Artipa National Museum of Natural History, Bucharest, Romania Author Gittenberger, Arjan Gittenberger Marine Research, Inventory & Strategy, Leiden, Netherlands Author Gogaladze, Aleksandre Naturalis Biodiversity Center, Leiden, Netherlands Author Mikhail Karpinsky Russian Federal Research Institute of Fisheries and Oceanography, Moscow, Russia Author Popa, Luis Grigore Antirpa National Museum of Natural History, Bucharest, Romania Author Sands, Arthur F Justus Liebig University, Giessen, Germany Author Vandendorpe, Justine Justus Liebig University, Giessen, Germany Author Wilke, Thomas Justus Liebig University Giessen Germany text ZooKeys 2019 827 31 124 http://dx.doi.org/10.3897/zookeys.827.31365 journal article http://dx.doi.org/10.3897/zookeys.827.31365 1313-2970-827-31 10B663895E424E5287D8F49E2405D651 10B663895E424E5287D8F49E2405D651 Hypanis plicata (Eichwald, 1829) *1829 G. [lycymeris] plicata Eichwald: 279, pl. 5, fig. 2a, b. 1838 Adacne [sic] plicata m. - Eichwald: 171-172. 1916 Adacna relicta Milaschewitch: 274-276, pl. 8, figs 10-13 [non figs 10-12 as indicated in the text]. 1926 Adacna relicta var. dolosmiana Borcea: 468-469, pl. 18, figs 156-158, pl. 21, fig. 2. 1952 Adacna (Hypanis) plicata (Eichwald, 1829). - Zhadin: 354-355, fig. 332. 1958 Adacna (Hypanis) plicata (Eichwald), 1829. - Nevesskaja: 50-51, pl. 9, figs 9-14. 1969 Hypanis plicata plicata (Eichw.). - Logvinenko and Starobogatov: 331-332, fig. 350. 1973 Hypanis plicata plicata Eichwald, 1829. - Grossu: 136, text fig. 14, pl. 1, fig. 5. 1973 Hypanis plicata relicta Milaschevitsch, 1916. - Grossu: 136, text fig. 15, pl. 1, figs. 6, 20-23. 1973 Hypanis dolosmaniana [sic] Borcea, 1826. - Grossu: 136, text fig. 16, pl. 1, figs 16-19. 1977 Hypanis plicata golbargae Tadjalli-Pour: 99, pl. 1, fig. 5. 2006a Hypanis plicata relicta (Milachevitch, 1916). - Munasypova-Motyash: 45-46. 2009 Adacna (Hypanis) plicata relicta Milaschevich, 1916. - Popa et al. 12, fig. 4. 2013 Hypanis plicata (Eichwald, 1829). - Kijashko in Bogutskaya et al.: 387, fig. 164, photo 56. 2016 Hypanis plicata plicata (Eichwald, 1829). - Vinarski and Kantor: 73. 2016 Hypanis plicata relicta (Milaschewitsch, 1916). - Vinarski and Kantor: 74. Status. Pontocaspian species, endemic to Caspian Sea Basin and Black Sea Basin. Type locality. "Sinum Astrabadensem" [Caspian Sea near Astrabad (= Gorgan, Iran)]. Distribution. Caspian Sea, western liman coast Black Sea Basin. Taxonomic notes. The Black Sea populations of H. plicata show a large range of morphological variation with elongated specimens that cannot be distinguished from Caspian H. plicata to severely stunted and irregularly shaped specimens that have been considered as a subspecies ( H. plicata relicta ) or as distinct species ( H. dolosmiana ) (e.g., Munasypova-Motyash 2006a ). These forms have intermediates indicating that the Black Sea Basin specimens are a single species that should be attributed to H. plicata even though the latter appear to have lived under lower salinities than their Caspian counterparts. Molecular studies are required to elucidate the status of the Black Sea Basin material. Conservation status. Not assessed. Fresh shells (including paired specimens) have been found at several beaches around the Caspian Sea (Turali, Dagestan, Russia; Suraabad , Azerbaijan; FW). The species has been reported alive from the Razim lake complex of the Romanian Black Sea coast by Popa et al. (2009) .