Diagnosis: Body moderately long, prominent mobile and forward-extending mental lobe on lower jaw, median fins set well back with dorsal fin shorter than and originating behind anal fin, depth of caudal peduncle 34–43% of its length, 23–25 dorsal fin rays, 28–31 anal fin rays, 56–64 scales in lateral series, 12–16 scales around caudal peduncle, head length 19–21% of standard length, body depth 27–32% of standard length, dorsal fin length 18.1–22.3% of standard length, length of snout 45–50% of head length, anal fin length 22.7–25.3% of standard length, and length of caudal peduncle 16.3–19.9% of standard length (Ref. 94473).
Description: Head with terminal mouth well in front of eye, mental lobe on lower jaw protruding beyond upper jaw; head and body dorsolaterally compressed (Ref. 94473). Dorsal fin situated about two-thirds of standard length from snout, obliquely oriented, anteriorly higher and posteriorly lower, distal margin sometimes only slightly crescent-shaped with anterior two or three rays longer than posterior rays, number of rays 23-25; anal fin opposite dorsal fin with distinctly more anterior origin, obliquely oriented, anteriorly lower and posteriorly higher, anterior rays longer than posterior ones, especially in males where they also appear stronger and often darkened, distal margin crescent-shaped, number of rays 28-31 (Ref. 94473). Scales cycloid with reticulate striae, scales extending anteriorly to operculum and pectoral fins; scales on caudal peduncle circumference, 12-16 (Ref. 94473). Caudal peduncle relatively deep, subcylindrical entire length, usually 16.3-19.9% in standard length (Ref. 94473). Electric organ discharge biphasic with weak pre-potential (Ref. 94473).
Colouration: Colour in life: brownish grey with many distinct dark-brown blotches, except on head and belly, purple hue depending on the angle of light incidence, paired fins light and transparent (Ref. 94473). Colour in preservation: medium brown, with darker, irregular blotches (Ref. 94473).