Diagnosed from all other species of the genus Pimelodus, except Pimelodus halisodous, Pimelodus jivaro, Pimelodus ornatus, Pimelodus pictus, and Pimelodus stewarti, by its supraoccipital process with a dorsal median crest; posterior nostril closer to anterior orbital border (vs. posterior nostril closer to anterior nostril than to anterior orbital border); distal portion of dorsal-fin rays 2-4 with a dark spot; caudal- fin base with two dark blotches. Distinguished from Pimelodus jivaro by having a shorter maxillary barbel, extending only slightly past caudal-fin base (vs. maxillary barbel extending beyond caudal-fin base); distal portion of dorsal-fin rays 2-4 with a dark spot, and caudal-fin base with two dark blotches. Differs from Pimelodus ornatus and Pimelodus pictus by the uniform grayish to yellowish coloration (vs. presence of bands or dark dots along flanks, respectively); from Pimelodus stewarti by its shorter posterior cleithral process (10.2-12.4 vs. 12.7-15.6 % of SL); caudal-fin base two dark blotches; and supraoccipital process with dorsal median crest; from Pimelodus halisodous by its shorter pectoral-spine (15.5-18.5 vs. 20.0-23.5% of SL); shorter snout (35.8-41.8 vs. 43.1-47.9% of HL); and fewer premaxillary tooth rows (5-9 vs. 13-16) (Ref. 79502).

Description: A iv-vi,6-8; P i+7-9; V i+5 (Ref. 79502).