Diagnosis: Enteromius atkinsoni is a member of the group of small Enteromius with a thin, flexible last unbranched dorsal ray and two pairs of well developed barbels (Ref. 87017). It differs from all the other species of this group in East Africa in having fewer scales in the midlateral line, and pores restricted to the first 4-9 scales of this series (Ref. 87017).

Description: Body slightly compressed, its depth a little greater than the head length (Ref. 87017). Caudal peduncle relatively deep, its depth 1.25-1.65 in its length (Ref. 87017). Snout rounded, shorter than the diameter of the eye; barbels well developed, anterior 0.50-0.75 times, and posterior 1.00-1.33 times the diameter of the eye (Ref. 87017). Dorsal-fin origin above or slightly in advance of the pelvic-fin origin; dorsal fin with 4 unbranched and 7-8 branched rays; the first unbranched ray is minute and hardly visible; the last unbranched ray is flexible and unossified; the last branched ray in both the dorsal and anal fins may be deeply divided, almost to its base (Ref. 87017). Midlateral longitudinal scale series with 25-27 scales, lateral line pores limited to the first 4-9 scales; 4-4.5 scales between the lateral line and the dorsal-fin origin; 2-3 scales between the lateral line and the pelvic-fin origin; 12 scales around the caudal peduncle; 9-10 scales in the predorsal row (Ref. 87017).

Colouration: In life watery brown dorsally, paler beneath, with a brassy metallic area on the operculum (Ref. 87017). Preserved specimens with dorsal surface of the head and body brownish, the scales are outlined in a reticulum of small spots, except on the ventral surface; typically there are 3 dark spots on the sides of the body, the last and usually largest, being situated on the base of the caudal; a thin, rather indistinct midlateral stripe runs from the first to the last of these spots; in a few specimens, the middle spot of this series may be doubled on one side, or this or the more anterior of the spots, may be indistinct; further small patches of dark pigment are apparent at the dorsal-fin origin and the base of the anal fin, in some specimens (Ref. 87017).