semilunaris, Gobius Heckel [J. J.] 1837:152, Pl. 8 (figs. 5-6) [Annalen des Wiener Museums der Naturgeschichte v. 2 (no. 1) (for 1840); ref. 2079] Maritza [Marizza] River, near Plovdiv, eastern Rumelia, Balkan region of Bulgaria. Syntypes: NMW 58144 (3). Ahnelt & Mikschi 2008:68 [ref. 29927] apparently incorrectly treat a holotype in NMW 58144.1 and provide information on the date of publication. •Synonym of Proterorhinus marmoratus (Pallas 1814) -- (Berg 1949:1100 [ref. 20662], Miller 1973:511 [ref. 6888], Kottelat 1997:181 [ref. 22952], Vasil'eva 1998:145 [ref. 23591], Pinchuk et al. in Miller 2004:72 [ref. 27853], Vassilev & Pehlivanov 2005:184 [ref. 28369]). •Valid as Proterorhinus semilunaris (Heckel 1837) (often dated 1839 or 1840) -- (Michajlova 1989:23 [ref. 20062], Stepien & Tumeo 2006:64 [ref. 31437], Freyhof & Naseka 2008:326 [ref. 29387], Kottelat & Freyhof 2007:590 [ref. 29996], Neilson & Stepien 2009:677 [ref. 30119], Scharpf 2009:14 [ref. 30400], Neilson & Stepien 2009:98 [ref. 30487], Page & Burr 2011:619 [ref. 31215], Freyhof 2011:286 [ref. 31742], Page et al. 2013:178 [ref. 32708], Stepien & Neilson 2013:2 [ref. 35325], Parin et al. 2014:503 [ref. 33547], Barbieri et al. 2015:110 [ref. 35029], Çiçek et al. 2015:152 [ref. 35151], Ćaleta et al. 2019:183 [ref. 37026], Özuluğ & Saç 2019:28 [ref. 36599], Çiçek et al. 2020:256 [ref. 37644], Manilo 2020:72 [ref. 37795], Kvach et al. 2021:48 [ref. 38595], Parenti 2021:77 [ref. 38603], Zarei et al. 2021:[6] [ref. 38799], Gaye-Siessegger et al. 2022:207 [ref. 40017], Çiçek et al. 2023:434 [ref. 40625], Nagy et al. 2023:358 [ref. 40348], Page et al. 2023:124 [ref. 40505], Çiçek et al. 2024:315 [ref. 40789]). Current status: Valid as Proterorhinus semilunaris (Heckel 1837). Gobiidae: Gobiinae. Distribution: Eurasia: Black Sea basin. Introduced/invaded in elsewhere in Europe, in Minnesota and Michigan (Lake Erie, U.S.A.) and Canada (from ship's ballast). Habitat: freshwater, brackish.