A revision of the extant species of Theodoxus (Gastropoda, Neritidae) in Asia, with the description of three new species

Theodoxus major Issel, 1865. A, B. Specimen (T. pallasi-morphotype) collected in the Caspian Sea, offshore from Aktau, Kazakhstan (UGSB 20712); C, D. Specimen (T. pallasi-morphotype) collected in the Aral Sea, Kazakhstan in 1979 (UGSB 19129); E–H. Specimen (T. pallasi-morphotype) from the Shahpol River, Aliabad Askar Khan, Iran (UGSB 18091); I–K. Specimen of T. major collected at the outflow of Lake Akna, Aknalich, Armenia (UGSB 20482); L–N. Specimen (T. astrachanicus-morphotype) collected in Utlyukskij Liman, Ukraine (UGSB 18130); O, P. Specimen of T. major collected in the Hrazdan River at the inflow of the Yerevan Reservoir, Armenia (UGSB 20496); Q–T. Specimen of T. major from Zoeram, North Khorasan, Iran (UGSB 21661); U, V. Specimen of T. schultzii collected in the Caspian Sea, offshore from Aktau, Kazakhstan (UGSB 20714); W–Y. Lectotype of T. pallasi from Caspian Sea, Dagestan, Russia (ZIN 54547/63); Za, Zb. Syntype of N. schultzii from the Caspian Sea (ZIN, no. 5 in systematic catalogue). Specimens E–K and O–T used in the phylogeny (Fig. 2). Scale bars: 1 mm.