opperiens, Gymnogobius Stevenson [D. E.] 2002:299, Figs. 4N, 8C [Species Diversity v. 7 (no. 3); ref. 26489] Yuapu River, Yamagoe, Toshima, Hokkaido, Japan. Holotype: NSMT-P 60922 [ex NSMT-P 14366]. Paratypes: HUMZ 40721 (1), 40723 (1), 42113 (1), 42115 (1), 42119 (1), 42127 (1), 42129 (1), 42131 (1), 42152-53 (1, 1), 42155 (1), 42171 (1), 70173 (1); NSMT-P 11055 (1), 11090 (4), 14338 (1), 14366 (1), 14937 (3), 16210 (5), 18772 (3), 19291 (1); UW 40100 (7), 40113 (20, 5 c&s), 42003 (11), 043542 (6), 044225 (22). •Valid as Gymnogobius opperiens Stevenson 2002 -- (Hagiwara 2003:38 [ref. 27188], Kim et al. 2004:56 [ref. 27747], Bogutskaya & Naseka 2004:223 [ref. 28183], Shedko & Chereshnev 2005:444 [ref. 30089] in subgenus Taranetziola, Bogutskaya et al. 2008:353 [ref. 30085], Parin et al. 2014:487 [ref. 33547], Dyldin & Orlov 2017:190 [ref. 35257], Dyldin et al. 2021:36 [ref. 38804], Ito et al. 2021:[9] [ref. 38897], Parenti 2021:298 [ref. 38603]). Current status: Valid as Gymnogobius opperiens Stevenson 2002. Oxudercidae: Gobionellinae. Distribution: East Asia: Sea of Japan and Pacific coast north to southern Kuril Islands (Korea, northern Japan, and Russia). Habitat: freshwater, brackish.