Diagnosis: Within the Congo basin Labeobarbus nzadinkisi can be distinguished from L. altipinnis, L. ansorgii, L. batesii, L. brauni, L. cardozoi, L. caudovittatus, L. dartevellei, L. fasolt, L. habereri, L. humphri, L. iphthimostoma, L. iturii, L. jubbi, L. longidorsalis, L. longifilis, L. lufupensis, L. macroceps, L. macrolepidotus, L. macrolepis, L. mawambi, L. mawambiensis, L. mirabilis, L. nanningsi, L. oxyrhynchus, L. paucisquamatus, L. stappersii, L. trachypterus, L. upembensis and L. wittei by its high number of lateral line scales, 35-41 vs. less than 34; from L. leleupanus by its low number of lateral line scales, 35-41 vs. 45-47; from L. tropidolepis and L. platyrhinus by its low number of scales between the lateral line and the dorsal and ventral midline, 4.5-5.5 and 5.5 vs. 7.5-8.5 and 7.5-9.5 in L. tropidolepis and 6.5-7.5 and 6.5-8.5 in L. platyrhinus, and from the latter by its low number of circumpeduncular scales as well, 12-14 vs. 16-18; from L. robertsi by the absence of papillae on the anterior edge of the lower jaw vs. with numerous well identifiable papillae; from L. progenys by its non-prognathous lower jaw vs. prognathous; from L. altianalis, L. gestetneri and L. somereni by its lack of both pairs of barbels vs. two pair of well-developed barbels; and from L. pellegrini by its short prepelvic length, 46.5-48.5% of standard length vs. 50.6%, its short pelvic length, 17.9-21.0% of standard length vs. 21.8%, and its large eye, 29.1-34.6% of head length vs. 27.1% (Ref. 127934). Further, L. nzadinkisi can be distinguished from the other members of the Inkisi complex, L. nzadimalawu and the intermediate/hybrid specimens by the presence of a cornified Varicorhinus real cutting edge on the outer edge of the lower jaw in combination with the absence of barbels and poorly developed fleshy lips on the lateral side of the lower jaw vs. never with a cutting edge but instead always with a free mental lobe in combination with two pairs of well-developed barbels and well-developed fleshy lips in L. nzadimalawu; although a cornified Varicorhinus real cutting edge can be found in some specimens, this most often in combination with at leats a single pair of well-developed barbels and well-developed fleshy lips in the hybrid specimens; in addition, L. nzadinkisi can be distinguished from L. nzadimalawu by its broad mouth width, 26.8-50.5% of head length vs. 16.1-26.5%, short head length, 20.1-22.1% of standard length vs. 23.0-26.4%, long dorsal-fin base length, 14.4-17.9% of standard length vs. 12.1-16.0%, and short prepectoral distance, 20.0-22.1% of standard length vs. 22.6-26.0% (Ref. 127934). Finally, L. nzadinkisi can be distinguished from Acapoeta tanganicae by its low number of lateral line scales, 35-41 vs. 57-67 (Ref. 127934). Within the adjacent Lower Guinea ichthyofaunal province, L. nzadinkisi can be distinguished from L. axelrodi, L. batesii, L. brevispinis, L. cardozoi, L. caudovittatus, L. compiniei, L. habereri, L. fimbriatus, L. jaegeri, L. malacanthus, L. mariae, L. mbami, L. micronema, mungoensis, L. roylii, L. sandersi, L. semireticulatus, L. steindachneri, L. tornieri, L. versluysii and L. werneri by its higher number of lateral line scales, 35-41 vs. less than 34; from L. aspius, L. lucius and L. progenys by its non-prognathous lower jaw vs. lower jaw clearly prognathous; and from L. rocadasi by its last unbranched dorsal-fin ray not being transformed into a well-developed spine, but instead being clearly segmented over approximately half its length, or 43.0-50.1% of dorsal-fin height vs. last unbranched dorsal-fin ray transformed into a spine, clearly segmented only at its most distal end; finally, L. nzadinkisi can be distinguished from Sanagia velifera by its high number of lateral line scales, 35-41 vs. 22-24 (Ref. 127934). Within the adjacent Quanza ichthyofaunal province, L. nzadinkisi can be distinguished from L. ansorgii, L. gulielmi, L. jubbi, L. nanningsi, L. rhinophorus, L. rosae and L. roylii by its high number of lateral line scales, 35-41 vs. less than 34; from L. clarkeae, L. ensifer and L. varicostoma by the absence of papillae on the anterior edge of the lower jaw vs. with well identifiable papillae; from L. lucius and L. progenys by its non-prognathous lower jaw vs. lower jaw clearly prognathous; and from L. boulengeri, L. ensis, L. girardi, L. steindachneri, L. stenostoma and L. rocadasi by its last unbranched dorsal-fin ray not being transformed into a well-developed spine, but instead being clearly segmented over approximately half its length, or 43.0-50.1% of dorsal-fin height vs. last unbranched dorsal-fin ray transformed into a spine, clearly segmented only at its most distal end (Ref. 127934).

Description: Labeobarbus nzadinkisi has a rather shallow body depth, low dorsal-fin height, and shallow and elongated caudal peduncle; a relatively small-sized Labeobarbus species with a maximum observed size of 205 mm standard length (Ref. 127934). Labeobarbus nzadinkisi has a typical Varicorhinus-mouth phenotype characterizd by the presence of a cornified cutting edge on the anterior edge of the lower jaw; anterior and posterior pair of barbels generally absent, but a minute pair of posterior barbels might be present; lower jaw always clearly shorter than upper jaw (Ref. 127934). Tubercles are present on all specimens except for the smallest and, as such, are likely to be present in males and females; tubercles are present at least on the snout and often on the dorsum of the head too, although in a different degree; large specimens of more than 180.0 mm standard length with conical tubercles over mid-ventral and lateral sides of the snout and the lateral sides of head below the eye reaching posteriorly up to area of the preopercular/opercular skin fold; a few larger tubercles are also present between nostril and eye; further, numerous and tiny tubercles are scattered over dorsal regions of snout, head and nape, between the posterior edge of the head and the anterior edge of the predorsal area; finally, remainder of body without tubercles (Ref. 127934). Lateral line scales with less sinuous and parallel striae towards their horizontal midlines but slightly radiating striae towards their upper and lower edge; number of striae on the posterior edge of these scales between about 46-48; total number of lateral line scales 35-41, number of predorsal scales 9-10, number of scales above lateral line 4.5-5.5, number of scales in-between lateral line and pelvic fin 3, number of scales in-between lateral line and ventral midline 5.5, number of circumpeduncular scales 12-14, number of dorsal-fin base scales 7-11, number of anal-fin base scales 4-5 (Ref. 127934). The pharyngeal teeth number is 2.3.4-5.3.2, with the first tooth of the inner row being absent on the left pharyngeal bone; on both the left and right pharyngeal bone there are two additional smaller teeth present median of the inner row; these are not firmly attached to the bone but rather are loosely embedded in the surrounding soft tissue; one of them well-developed, the other one is more like a dome-like cusp (Ref. 127934). Number of unbranched dorsal-fin rays 4, number of branched dorsal-fin rays 10-12, total number of dorsal-fin rays 14-16, number of unbranched anal-fin rays 3, number of branched anal-fin rays 6, total number of anal-fin rays 9, number of pectoral-fin rays 12-15, number of pelvic-fin rays 8, number of caudal-fin rays 17 (Ref. 127934).

Colouration: Live specimens silvery grey on lateral sides of head and body; dorsal midline of head blackish; dorsal midline of body, in front, along and behind the dorsal fin, with a yellowish-green silver hue; proximal part of scales, scale pockets, darker in colour, especially for the scales above the lateral line; fins of comparable blackish overall colour with their distal margins whitish translucent; fin rays whitish; ventral side of head and body yellowish-white (Ref. 127934). In alcohol, small-size specimens of less than 130 mm standard length uniformly brownish, becoming darker towards the dorsal midline of head and body; scale pockets, especially those above the lateral line, typically darker brown due to more numerous melanin dots; anteriormost ventral part of snout and jaws, ventral side of head and belly yellowish light brown; fins whitish translucent and even transparent with sparsely set minute dark brown or blackish melanin dots; large-size specimens of more than 183 mm standard length uniformly dark brown, becoming even darker above the lateral line towards the dorsal midline of the head and body; no distinct scale pocket colouration at first sight, although the proximal part of the scales is dark brown while the overall distal border is translucent or even transparent; anteriormost ventral part of snout and jaws, ventral side of head and belly yellowish light brown; head generally somewhat lighter of colour compared to body; fin tissues faintly brownish or even more blackish; fin rays often more white-yellowish; distal edge of fins whitish translucent and sometimes even transparent (Ref. 127934).