Diagnosis: Synodontis carineae is distinguished from all its congeners by the following unique combination of characters: entire anterior edge of dorsal spine not serrated, vs. entire anterior edge of dorsal spine serrated in S. batesii and S. albolineata; posterior margin of opercula without an opercular spine and caudal fin without two black patches, vs. generally with an opercular spine and two black patches, one on the upper and one on the lower lobe of the caudal fin in S. acanthoperca and S. punu; 18-24 mandibular teeth, vs. 50-59 in S. haugi and 85-90 in S. polyodon; maxillary barbels bordered with a well-developed, broad membrane at least as broad as barbel thread, vs. bordered with a very narrow or without membrane in S. marmorata and S. schall; snout relatively long, postocular length short, 44-58% snout length, vs. snout short, postocular length 80-107% snout length in S. nigrita, 67-76 in S. ngouniensis, 82-93 in S. robbianus, and 72-105 in S. steindachneri; dorsal spine relatively short, 16.6-23.5% of standard length, vs. dorsal spine relatively long, 27.5-32.1% of standard length in S. tessmanni, almost isometric or slightly negative allometric; head relatively narrow, width 60.1-68.5% of head length, vs. head relatively wide, width 80.5-96.2% of head length in S. obesus/rebeli-complex; 75.7-83.7 in S. violacea (Ref. 86529).

Description: Synodontis carineae is a medium-sized species; head width at base of pectoral fins equal to or somewhat shorter than head depth at base of pectoral fins; predorsal profile rather straight from tip of snout up to vertical through middle of eye, then rather straight, but clearly less steep, up to anterior dorsal-fin base; postdorsal profile straight, inclined posteriorly; anus and urogenital opening situated below anterior origin of adipose fin; lateral line complete, curved slightly upward at level of humeral process; straight further posteriorly, and inclined towards base of caudal fin; gill opening restricted to lateral aspect of head; upper tip of opercular opening posteriorly vertical through middle of pectoral-fin base; dorsally rea&ching approximately up to dorsal point of humeral process; ventral tip of opercular opening situated at vertical approximately midway between posterior border of eye and anterior border of pectoral-fin base; operculum without spine (Ref. 86529). Three pairs of barbels; maxillary barbel long, fine unbranched and without crenulations, extending up to or just beyond posterior margin of head with well-developed basal membrane, i.e. towards its base, as wide as barbel thread itself; outer mandibular barbel, when stretched along lateral side of head, reaching approximately up to posterior border of eye or midway of horizontal distance between posterior border of eye and anterior base of pectoral spine; with numerous, ±8-12, short, often paired tuberculated branches; numerous secondary branches present; inner mandibulary barbel, when stretched along lateral side of head, reaching approximately up to anterior border of eye or midway of horizontal eye diameter; with numerous, ±7-9, short, often paired, tuberculated branches; numerous secondary branches present (Ref. 86529). Eyes rather small, in supero-lateral position and about 3/4 up to 4/4 of interorbital distance; orbit with a free margin; interorbital area flat; mouth inferior, approximately three times as long as wide; mouth opening, horseshoe-shaped in ventral view due to enlarged postero-lateral, finely papillated, lobes of lips; anterior nostrils slightly closer together than posterior nostrils; anterior nostrils tubular with a short raised rim; posterior nostrils with elevated flaps along anterior margin (Ref. 86529). All teeth unicuspid; premaxillary toothplate wide and interrupted along midline; primary premaxillary teeth arranged in several irregular rows, approximately 28-36 on first row; 18-24 mandibular teeth, organised more or less into a single row merging replacement teeth in an irregular, second, anteriorly situated row; distal tip of teeth clearly curved upwards (Ref. 86529). Dorsal fin II,6-8; dorsal spine striated, nearly straight, entirely smooth along anterior margin but with 6-11 serrations on distal half of posterior margin; adipose fin rather large; pectoral fin I,6-9; pectoral spine roughly equal in length to dorsal spine, striated, slightly curved backwards, generally with numerous spiny fine serrations along outer (anterior) margin, 10-24; serrations generally starting at base of spine; however, in a few specimens no serrations on proximal 1/4 of spine; pectoral spine with generally less numerous, but stronger spiny serrations along inner (posterior) margin, 11-22; serrations on proximal 3/4 of spine; tip of adpressed pelvic fin reaching, or almost reaching, anal-fin origin; anal-fin origin approximately below first third of adipose fin; posterior edge of anal fin approximately below last third of adipose fin; anal fin iii-iv,7-9; caudal fin forked, upper lobe generally somewhat longer than lower lobe, and both lobes slightly pointed (Ref. 86529). Humeral process triangular; granulous; 1.2-2.1 times as long as high; without ventral ridge; with a rather straight upper margin and terminating in a blunt point; no-slit-like axillary pore just ventral to humeral process (Ref. 86529).

Colouration: In life, overall colour vivid yellowish with large brownish, irregularly shaped and often indistinct spots; pupil black, iris with an orange edge directly around pupil; approximately upper most 3/4 of iris blackish; lower 1/4 greyish; lips whitish with a well-marked reddish hue; thread of maxillary barbels whitish or light brown; membrane dark brownish or yellowish; dorsal part of snout brownish; interorbital and posterior dorsal surface of head with numerous medium-sized, poorly delimited, sometimes confluent, dark brown spots; flanks with two more or less parallel, lateral series of irregularly shaped dark brownish spots or undulating stripes, one mostly just above and second mostly just below lateral line; anterior part of flanks more intense yellowish than posterior part; dorsal midline of body with two, often not too well demarcated, parallel series of dark brownish, elongated, spots; dorsal, adipose and caudal fins vivid yellowish with irregularly-shaped, large, dark brown spots; adipose fin of some specimens dark brownish with a yellowish transparent outer margin; pectoral, pelvic, and anal fins brownish, transparent, with, vivid yellow shine, with some reddish hue at base; ventral side of head and body uniformly whitish (Ref. 86529). In preserved specimens all above mentioned yellowish or reddish pigment become whitish; dark brownish spots remain, resulting in increased contrast between whitish and ark brownish coloured parts (Ref. 86529).