9.1 cm SL (male/unsexed; (Ref. 91772))
Diagnosis: Petrocephalus frieli is distinguished from all other Petrocephalus species of Central Africa by the following combination of characteristics: body coloration brownish without an intense subdorsal pigmentation mark; 21-24 branched rays in the dorsal fin and 28-30 branched rays in the anal fin; more than 13 scale rows between the anterior base of the anal fin and the lateral line; and three distinct electroreceptive rosettes on the head (Ref. 91772).Description: Body ovoid, longer than high, and laterally compressed (Ref. 91772). Snout short and round; mouth small, sub-terminal, opening under the posterior half of the eye (Ref. 91772). Teeth small and bicuspid; 9-14 in a single row in the upper jaw, 18-22 in a single row in the lower jaw (Ref. 91772).Colouration: Body background colour silver-white with metallic reflection on the flanks, darker on the snout, forehead and along the dorsal edge until the caudal peduncle (Ref. 91772). Scattered melanophores over the body, denser and larger on the head (Ref. 91772). All fins whitish, translucent, with melanophores marking the lepidotrichia (Ref. 91772).