koshewnikowi, Cottus Gratzianov [V. I.] 1907:658 [Zoologischer Anzeiger v. 31 (no. 21/22); ref. 1872] Goredva River, Ligachevo village, Moscow Oblast, Russia. Lectotype: ZMMU P-2688. Paralectotypes: ZMMU P-2001 (4), P-2658 (20), P-2688 (2, now 1), P-3118 (1), P-3121 (3), P-3912 (1). Type catalog: Svetovidova 1978:259 [ref. 9011], Vasil'eva et al. 2001:79-80 [ref. 25714]. Also in Gratsianov 1907:315 [ref. 1871], earliest not researched. Name also seen as Gratsianow. Lectotype designated by Sideleva et al. 2015:33 [ref. 35276]. •Synonym of Cottus gobio Linnaeus 1758, but a valid subspecies koshewnikowi Gratzianov 1907 -- (Berg 1949:1147 [ref. 20662], Lelek 1987:274 [ref. 22962], Mitrofanov & Dukravec 1989:282 [ref. 37748], Reshetnikov et al. 1997:758 [ref. 24702], Sideleva 1998:151 [ref. 23595]). •Synonym of Cottus gobio Linnaeus 1758 -- (Kottelat 1997:169 [ref. 22952], Tsvetkov et al. 2001:121 [ref. 26836]). •Valid as Cottus koshewnikowi Gratzianov 1907 -- (Bogutskaya & Naseka 2004:187 [ref. 28183], Freyhof et al. 2005:163 [ref. 28259], Fricke 2007:29 [ref. 30577], Kottelat & Freyhof 2007:511 [ref. 29996], Goto et al. 2014:[11] [ref. 33456], Sideleva et al. 2015:429 [ref. 33770], Sideleva et al. 2015:34 [ref. 35276], Pozdeev et al. 2022:4 [ref. 39511], Sideleva et al. 2022:41 [ref. 39468], Sideleva & Shidkov 2024:492 [ref. 41080]). Current status: Valid as Cottus koshewnikowi Gratzianov 1907. Cottidae. Distribution: Eastern Europe: Volga River basin and rivers of the eastern part of the Baltic Sea, Russia. Habitat: freshwater, brackish.