mastacembelus, Ophidium Banks [J.] & Solander [D. C.] in Russell 1794:209, Pl. 6 [Natural History of Aleppo. Second Edition v. 2; ref. 19817] Kowick River, Aleppo [Quwayq River, Halab, Syria]. Syntypes: BMNH 1955.6.25.4-6 (3). We here treat Ophidium mastacembelus Banks & Solander 1794 as a nomen protectum, due to prevailing usage. See also Ophidium simack Walbaum 1792. Discussion on authorship see Kottelat 2022:448 [ref. 39410]. •Synonym of Mastacembelus simack (Walbaum 1792) -- (Kottelat 2022:446 [ref. 39410]). •Valid as Mastacembelus mastacembelus (Banks & Solander 1794) -- (Travers 1984:143 [ref. 5147], Coad 1991:22 [ref. 15702], Coad 1995:32 [ref. 23608], Coad 1996:71 [ref. 25297], Coad 1996:86 [ref. 25304], Coad 1998:103 [ref. 23869], Fricke et al. 2007:76 [ref. 29533], Coad 2010:258 [ref. 36620], Esmaeili et al. 2010:375 [ref. 33391], Jouladeh-Roudbar et al. 2015:895 [ref. 34062], Çiçek et al. 2015:151 [ref. 35151], Coad 2015:2 [ref. 35412], Esmaeili et al. 2017:94 [ref. 35254], Esmaeili et al. 2018:75 [ref. 36089], Çiçek et al. 2020:258 [ref. 37644], Jouladeh-Roudbar et al. 2020:248 [ref. 37983], Bayhan 2021:250 [ref. 40683], Al-Faisal et al. 2022:1408 [ref. 39565], Çiçek et al. 2023:28 [ref. 40616], Çiçek et al. 2023:434 [ref. 40625], Saad et al. 2023:38 [ref. 40501], Çiçek et al. 2024:323 [ref. 40789]). Nomen Protectum. Current status: Valid as Mastacembelus mastacembelus (Banks & Solander 1794). Mastacembelidae. Distribution: Asia Minor and Middle East: Tigris River, Kor River and Persian Gulf basins (Turkey, Syria, Iraq and Iran). Habitat: freshwater, brackish.