crassus, Mastacembelus Roberts [T. R.] & Stewart [D. J.] 1976:305, Pl. 14 (fig. d) [Bulletin of the Museum of Comparative Zoology v. 147 (no. 6); ref. 7388] Lower Congo River, near Bulu, Democratic Republic of Congo, 5°01'S, 14°01'E. Holotype: MCZ 50257. Paratypes: BMNH 1976.5.21.109-118 [ex MCZ 50258] (10); MCZ 50258 (now 161, 9 c&s), 50318 (14), 50400 (1); MRAC 76-17-P-39-42 [ex MCZ 50258] (4); USNM 216374 [ex MCZ 50258] (10). •Valid as Caecomastacembelus crassus Roberts & Stewart 1976 -- (Travers 1984:145 [ref. 5147], Gosse 1986:422-423 [ref. 6194]). •In Mastacembelus to agree with current placement of Caecomastacembelus. •Valid as Mastacembelus crassus Roberts & Stewart 1976 -- (Proudlove 2006:269 [ref. 28992], Vreven & Stiassny 2009:218 [ref. 30676], Kanu et al. 2022:67 [ref. 39409]). Current status: Valid as Mastacembelus crassus Roberts & Stewart 1976. Mastacembelidae. Distribution: Western-central Africa: Congo River (Democratic Republic of Congo). Habitat: freshwater.