Diagnosis: This species is distinguished by the following characters: anterior cavities of lateral ethmoids (where the olfactory bulb is housed) greatly developed; bony excrescence of posterolateral process of lateral ethmoids prominent, completely closing the lateral fenestrae; basioccipital with a laminar bony crest bordering the anterior foramen of aortic tunnel (Ref. 86580).

Description: Body elongated and robust; mouth sub-terminal, with fleshy lips; eyes large (4.5 to 6.5 times in head length); cephalic plate strongly granulated, extending over the eyes; lower branch of the first gill arch with 9 to 10 gill rakers; body from blue-black to olive-brown, sometimes with blue, green or violent iridescence; dorsal surface of the paired fins and distal region of the anal fin occasionally black; edge of anal fin white; maxillary barbels black (Ref. 55763).