Adacna laeviuscula

Wesselingh, Frank, Poorten, Jan Johan ter, Kijashko, Pavel, Albrecht, Christian, Anistratenko, Olga Yu, Frolov, Pavel, Gándara, Alberto Martinez, Gittenberger, Arjan, Gogaladze, Aleksandre, Mikhail Karpinsky, Popa, Luis, Sands, Arthur F, Vandendorpe, Justine & Wilke, Thomas, 2019, Mollusc species from the Pontocaspian region - an expert opinion list, ZooKeys 827, pp. 31-124 : 34-35

Adacna laeviuscula (Eichwald, 1829)

*1829 G. [lycymeris] laeviuscula Eichwald: 279, pl. 5, fig. 1a, b.

1838 Adacna Laeviuscula m. - Eichwald: 170-171.

1841 Adacna laeviuscula . - Eichwald: 281-282, pl. 39, fig. 1 a–d.

1905 Adacna laeviuscula (Eichwald, 1829). - Ostroumov: pl. 2, fig. E.

1907 Adacna laeviuscula . - Ostroumov: 25, text fig., pl. 4, figs 6-8.

1952 Adacna (Adacna) laeviuscula (Eichwald, 1829). - Zhadin: 353-354, pl. 9, fig. 331.

1958 Adacna (Adacna) laeviuscula (Eichwald), 1829. - Nevesskaja: 49-50, pl. 9, figs 15-18.

1969 Hypanis laeviuscula laeviuscula (Eichw.). - Logvinenko and Starobogatov: 337, fig. 353(5).

1973 Hypanis laeviuscula laeviuscula Eichwald, 1829. - Grossu: 144-145, text fig. 29.

2013 Adacna laeviuscula (Eichwald, 1829). - Kijashko in Bogutskaya et al.: 377, fig. 154, photo 48.

2016 Adacna (Adacna) laeviuscula (Eichwald, 1829). - Vinarski and Kantor: 64.

Status. Pontocaspian species, endemic to Caspian Sea and possibly Black Sea Basin.

Type locality. Azerbaijan, Caspian Sea, Gulf of Baku is the type locality given by Vinarski and Kantor (2016) and this is written on the label of the type material. However, the type description reads "Hab. australem ripam maris caspii, in sinu Astrabadensi" [southern border of the Caspian Sea, in bight of Astrabad (= Gorgan, Iran)]. Further research on the labels and documentation is required to assess whether a new lectotype or even neotype must be assigned for Adacna laeviuscula .

Distribution. Caspian Sea; limans, coastal lakes, and Danube Delta in Black Sea Basin (in case A. fragilis will be shown to be a synonym of A. laeviuscula ).

Taxonomic notes. See discussion under A. fragilis .

Remarks. Kijashko in Bogutskaya et al. (2013) list the presence of this species at 30-60 m water depth in the Caspian Sea from muddy, sandy-mud, and rarely sandy bottoms. Logvinenko and Starobogatov (1969) reported the species from the northern, middle, and southern Caspian Sea basins down to 80-85 m water depth. In the Caspian Sea, the species has not been found in areas with salinities below 4‰. However, the common occurrence of fresh (paired) specimens on beaches seen at Turali (Dagestan, Russia) and northern Azerbaijan indicates this species maintains viable populations in foreshore and possibly even shoreface habitats.

Conservation status. Not assessed.