Theodoxus fluviatilis (Linnaeus, 1758). A–D. Specimen collected close to Oued Laabid, Morocco (UGSB 18106) (Fig. 2); E–H. Specimen from the Danube River, Wörth an der Donau, Germany (UGSB 24173); I–L. Specimen (T. euxinus-morphotype) collected in the Papuç Creek, Kıyıköy, Turkey (UGSB 24172) (Fig. 2); M–P. Specimen (T. euxinus-morphotype) from Ovidiopol, Ukraine (UGSB 18124); Q–S. Specimen (T. heldreichi-morphotype) collected in Lake Eğirdir, Turkey (UGSB 20361); T, U. Specimen (T. danasteri-morphotype) collected in Krasna Kosa, Ukraine (UGSB 18417) (Fig. 2); V. Opercula of a T. danasteri-morphotype from Lake Skadar, Montenegro (UGSB 24171). Specimens A–D, I–L and T–U were used in the phylogeny (Fig. 2). Scale bars: 1 mm.