Diagnosis: Chiloglanis msirii can be distinguished from its congeners in the Congo basin by the following unique combination of characters: an oral disc without a mid-ventral cleft, vs. an oral disc with a well-developed mid-ventral cleft in C. asymetricaudalis, C. angolensis, C. carnosus, C. congicus, C. igamba, C. kalambo, C. kazumbei, C. lufirae, C. lukugae, C. macropterus, C. marlieri, C. micropogon, C. microps, C. orthodontus, C. pojeri, C. productus, C. reticulatus, C. ruziziensis, and shallow mid-ventral cleft in C. elisabethianus (Ref. 128503). Outside the Congo basin, C. msirii can be distinguished from all its congeners from southern Africa, except for C. swierstrai, by the following unique combination of characters: an oral disc without a mid-ventral cleft, vs. an oral disc with a well-developed mid-ventral cleft in C. anoterus, C. bifurcus, C. fasciatus, C. neumanni and C. paratus; and a forked caudal fin without apparent sexual dimorphism, vs. emarginate in both sexes in C. emarginatus and C. pretoriae (Ref. 128503). Finally, C. msirii can be distinguished from the most similar species, C. swierstrai, by a relatively robust body with few total number of vertebrae, 33-36, vs. a more slender body with a higher number of total vertebrae, 37-40; its relatively large body width at the pectoral-fin insertion, 22.0-27.2% of standard length vs. more slender, 17.3-20.3% of standard length; its deep caudal peduncle, 10.2-12.9% of standard length, vs. shallower, 8.3-9.8% of standard length; its long predorsal length, 34.4-41.8% of standard length, vs. shorter, 30.6-34.7% of standard length; and its long prepelvic length, 51.8-59.8% of standard length, vs. shorter, 46.1-51.9% of standard length (Ref. 128503).

Description: Body compressed posteriorly and depressed anteriorly; predorsal profile gently convex; body profile straight to slightly convex along dorsal-fin base, straight from insertion of last dorsal-fin ray to adipose-fin origin, and slightly convex along caudal peduncle; preanal profile straight; anus and urogenital opening located just behind vertical of origin of adipose fin; head region and anterior part of dorsal fin covered with numerous rounded unculiferous tubercles; lateral line complete, situated at mid-lateral level (Ref. 128503). Head depressed and broad when viewed dorsally; mouth inferior made of greatly expanded and united upper and lower lips, oral disc ventrally directed; oral disc round and moderate in size; barbels in three pairs and well-developed; maxillary barbel long, thick and unbranched, originating on anterolateral region of oral disc; mandibular barbels incorporated into lower lip; medial primary mandibular barbel long, well-developed, originating on about midline of lower lip and with a short, rounded and bump-like, auxiliary barbel on each side of it; lateral primary mandibular barbel lateral to medial primary mandibular barbel, about midway between latter and postero-lateral corner of oral disc; lateral primary mandibular barbel bordered medially only by short, rounded and bump-like, auxiliary barbel; primary mandibular barbels originating on posterior region of oral disc; lateral and median auxiliary barbels of median and lateral primary mandibular barbels, respectively, often merged to single, short, rounded and bump-like, auxiliary barbel; lateral primary mandibular barbel clearly longer than medial mandibular barbel; no median cleft (Ref. 128503). Eye small, round and supero-laterally positioned; posterior nares slightly further apart from each other than anterior ones; anterior nare tubular with short-raised rim; posterior nare with elevated flap along anterior margin (Ref. 128503). Dorsal fin located at anterior third of body; dorsal-fin spine long and straight, smooth along both anterior and posterior margins; adipose fin moderately sized, origin at posterior third of body; caudal fin forked; pectoral fin margin convex, pectoral spine long and posteriorly curved, with no or only weak serrations; pelvic-fin origin at vertical through mid-point of bases of dorsal and adipose fins; pelvic-fin margin convex, distal tip reaching anal-fin origin; anal fin located directly below adipose fin; distal profile of anal fin convex (Ref. 128503). Postcleithral process long, triangular and terminating in a sharp tip (Ref. 128503). No apparent sexual dimorphism in shape or size of fins, body ornamentation, or tuberculation of skin (Ref. 128503).

Colouration: In life, specimens with overall whitish yellow background colour inter spaced with dark brown, irregularly shaped network; as a result, flanks with six more or less prominent light whitish yellow blotches; first, least prominent one, located ahead of dorsal fin; second located just behind dorsal-fin terminus; two more blotches located respectively ahead of pelvic and anal-fin origins; and other two located respectively just posterior to adipose and anal termini; bases of dorsal, adipose, and anal fins dark brown; lateral line whitish yellow; on dark brown, irregular shaped, network, two small, round, pale yellow spots between dorsal fin and lateral line; and four additional ones between adipose fin and lateral line; head with uniformly dark yellowish-brown background colour and numerous closely-spaced small dark brown spots; iris dark brown speckled with numerous minute dark brown spots; pupil with thin whitish yellow rim; oral disc, barbels, anus and urogenital whitish, but proximal half of maxillary barbels with some minute dark brown dots; ventral surface of head and body mainly uniformly whitish, with numerous minute dark brown spots near base of oral disc and towards inner base of pelvic fins to end of anal fin; fins lightly pigmented, whitish yellow, translucent or sometimes even transparent with scattered minute dark brown dots; dark brown irregular blotch over whitish yellow background present on both caudal fin lobes; blotch on upper lobe small and free, i.e. not reaching dark brown coloured caudal-fin base and hardly covering distal tip of upper lobe; blotch on lower lobe larger and well-connected with dark brown coloured caudal-fin base and, more fully, covering distal tip of lower lobe (Ref. 128503). In preserved specimens, whitish yellow background colour of body varying from light brown to whitish yellow whereas fin colour becomes pales; in addition, dark brown network, blotches, and dots become more pronounced and readily discernible (Ref. 128503).