Petrocephalus frieli Lavoué, 2012

From Lavoué (2012):

Body ovoid longer than high (mean SL/H = 2.9) and laterally compressed. Head length 3.6 times (mean) in standard length. Snout short (mean HL/SNL = 6.0) and round. Mouth small (mean HL/MW = 4.2), sub-terminal, opening under the posterior half of the eye. Teeth small and bicuspid, a median of 11 teeth in a single row in the upper jaw, a median of 20 teeth in a single row in the lower jaw. Dorsal and anal fins originate in the posterior half of the body (mean SL/PDD = 1.6 and mean SL/PAD = 1.7). Pre- dorsal distance slightly greater than the pre-anal distance (1.0 ≤ PDD/PAD ≤ 1.1). Median dorsal fin branched rays of 23. Median anal fin branched rays of 29. Scales cover the body, except for the head. Lateral line visible and complete, with a median of 38 pored scales along its length. Twelve scales around the caudal peduncle. Median of 16 scales between the anterior base of the anal fin and the lateral line. Caudal peduncle thin (mean CPL/CPD = 2.7). Skin on head thick, turning opaque with formalin fixation. Knollenorgans visible, clustered into the three distinct rosettes of Harder (1968).

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. Presence of a very faded subdorsal spot below the anterior part of the dorsal fin only on the specimens from Lake Bangweulu. Not observed in the other specimens. Scattered melanophores over the body, denser and larger on the head. All fins whitish, translucent, with melanophores marking the lepidotrichia.