Nannopetersius mutambuei Wamuini Lunkayilakio & Vreven 2008

Diagnosis: Nannopetersius mutambuei is distinguished from its two congeners by the following combination of characters: lateral line with 28-30 scales and 27-30 pored scales, vs. 30-35 and 32-35 in N. ansorgii and 28-33 and 27-33 in N. lamberti; 5.5-6.5 scales between the origin of the dorsal fin and the lateral line, vs. 6.5 in N. ansorgii and 6.5-7.5 in N. lamberti; 10-13 gill rakers on the ceratobranchial of the first branchial arch, vs. 14-17 in N. ansorgii and 10-12 in N. lamberti; length of caudal peduncle 135.7-151.9% of its depth, vs. caudal peduncle nearly as long as deep in N. ansorgii and N. lamberti; snout length 26.6-29.2% of head length, vs. 18.4-23.0% in N. lamberti; eye diameter 31.7-39.6% of head length, vs. 46.0-56.2% in N. lamberti; and no broad dark band in life, however present in preserved specimens, and no additional black spots on caudal and distal blackish band on anal fin, vs. a faint dark medio-lateral band, in preserved specimens, hardly visible anteriorly but better marked on the caudal fin and no additional black spots on caudal and anal fin in N. ansorgii, and a broad, black, medio-lateral band in life as well as preserved specimens, distal part of both upper and lower caudal-fin lobe with a black spot and distal margin of anal fin blackish in N. lamberti (Ref. 79819).Description: Small-sized species; snout somewhat shorter than eye; mouth terminal with a slightly prominent lower jaw (Ref. 79819). Gill rakers on first gill arch thin and relatively well-spaced (Ref. 79819). Teeth of outer row of upper jaw alternating with those of inner row; teeth on outer row of upper jaw tricuspid, teeth of inner row a little larger and with five cusps; usually 4 teeth on outer and 8 teeth on inner row of upper jaw; external mandibular teeth with 5 cusps; both inner teeth of lower jaw small and conical (Ref. 79819). Complete lateral line with 28-30 scales and 27-30 pored scales (Ref. 79819). Dorsal fin with 2 simple and 8 branched rays; pectoral fin longer than pelvic fin but not reaching base of latter; pelvic fin originating approximately below third branched ray of dorsal fin; caudal fin forked with sharp-pointed lobes (Ref. 79819).Colouration: In life, general colour silvery with greenish dorsal region (Ref. 79819). Caudal and adipose fin bright red; anal, pectoral, pelvic and dorsal-fin base yellowish; distal edge of fins reddish (Ref. 79819). Peripheral parts of iris reddish; blackish opercular spot; no dark mid-lateral band visible in living specimens (Ref. 79819). In preserved specimens, general colour brownish on dorsal midline and dorsal flank above black mid-lateral band, whitish on ventral midline and ventral flank up to black mid-lateral band; black mid-lateral band extending from posterior margin of operculum to caudal-fin base up to posterior edge of median caudal-fin rays; humeral spot sometimes visible but often hidden by dark mid-lateral band (Ref. 79819).

Dorsal spines (total): 0; Dorsal soft rays (total): 10; Analspines: 0; Analsoft rays: 25 - 27

Nannopetersius mutambuei is a species of fish in the African tetra family, only found in the Inkisi River upstream of the Sanga dam in the lower Congo River basin, in the Democratic Republic of the Congo. This species reaches a length of 12.0 cm (4.7 in).