Diagnosis: Cyphomyrus lufirae is distinguished from all its congeners, C. aelsbroecki, C. cubangoensis, C. discorhynchus, C. macrops, C. psittacus and C. wilverthi, by a larger caudal peduncle depth, 6.8-8.4% of standard length vs. smaller, 5.3%, 6.1-6.7%, 5.7-7.0%, 5.2%, 5.8% and 6.2% respectively, and a higher number of circumpeduncular scales, 14-16, rarely 12-13 vs. exclusively 12 in all congeners except for C. discorhynchus, which rarely also possesses 13 circumpeduncular scales (Ref. 122874). In addition, C. lufirae differs from C. macrops, C. psittacus and C. wilverthi by a lower number of dorsal fin rays, 27-32 vs. higher, 36-37, 33-41 and 38-40 respectively; and from C. aelsbroecki, C. cubangoensis and C. discorhynchus by a longer prepelvic distance, 41.0-43.8% of standard length vs. shorter, 39.7%, 38.9-39.1% and 37.0-41.0% respectively (Ref. 122874).
Description: Deep body, 2.8-3.5 times in standard length, laterally compressed (Ref. 122874). Predorsal profile convex (Ref. 122874). Head broadly rounded, 3.4-3.9 times in standard length; snout rounded and projecting beyond mouth, 4.1-5.2 times in head length; mouth small and inferior; chin with a short bulbous protuberance, nostrils closer to eye than mouth; interorbital space 3.0-4.2 times in head length (Ref. 122874). Teeth in upper jaw 2-5; teeth in lower jaw 3-7 (Ref. 122874). Dorsal and anal fins obliquely orientated; dorsal fin length equal or slightly longer than head, its origin situated anterior to anal-fin origin, and its base longer than that of the anal fin; distance between pelvic and anal fins relatively equidistant to pectoral-fin length; distal end of pectoral fin pointed, shorter than head length; dorsal-fin rays 27-32; anal-fin rays 21-25; pectoral-fin rays 10; pelvic-fin rays 6 (Ref. 122874). Scales on lateral line 60-66; circumpeduncular scales 12-16; scales between dorsal and anal fins 20-34; scales between dorsal fin and lateral line 16-19; scales between pelvic fin and lateral line 15-18 (Ref. 122874). Caudal peduncle 2.4-3.2 times as long as deep (Ref. 122874). Total number of vertebrae 38-39 (Ref. 122874).
Colouration: Colouration in life: overall body colouration dull silver, tinged with black and brown and yellowish overtone especially on head; yellowish colouration more intense in specimens from downstream Kyubo Falls and from Luvilombo River; fins greyish to black yellowish at their base; the silver colouration in particular is sometimes less intense or translucent for pelvic and caudal fins; with an oblique black band from anterior base of dorsal-fin up to third or fourth scale row below the lateral line; the oblique black band is less conspicuous in darker coloured specimens, but is more discernible in the yellowish coloured specimens of Lower Lufira and Luvilombo River (Ref. 122874). Colouration in alcohol: specimens from the Middle Lufira chocolate to blackish whereas those from Lower Lufira yellowish or brown; oblique black band often becoming more distinguishable than in life; fins greyish to black or translucent (Ref. 122874).