Diagnosis: two pairs of mandibular barbels; dorsal fin with a spine and 35 soft branched rays; pectoral with 7-8 branched rays; 7-8 branchiostegal rays on one side of head; 31-46 branched anal fin rays; dark mid-dorsal line continuing on upper half of caudal fin, sometimes somewhat bent downwards near posterior border of that fin; dark lateral line streak continues straight over caudal peducle and bends downwards slightly on caudal fin (Ref. 43912).

Description: 7-8 branched pectoral fin rays; 31-46 branched anal fin rays; 3-5 branched soft dorsal rays; 37-39 non-fused vertebrae; 7-8 branchiostegal rays on one side of head; caudal peduncle in general somewhat longer than deep but in some cases slightly deeper than long; nasal barbel reaching at least to anterior and at maximum to posterior border of operculum; maxillary barbel rather long, usually reaching at least to midway along pectoral spine and at maximum to somewhat beyond its end; in one paratype these barbels considerably shorter, reaching to only just beyond eye, but this is clearly an aberrant specimen; inner mandibular barbel rather short and at maximum reaches to just beyond eye; outer mandibular barbels reach at least to just beyond base of pectoral spine and at maximum to just beyond midway spine; inner side of pectoral spine very feebly serrated, serrations sometimes difficult to distinguish; posterior side of dorsal fin spine also feebly serrated; head rather narrow and rounded; snout reaching slightly beyond lower jaw; eye in lateral position; caudal fin forked; tooth plates on jaws and palate (vomer and palatine) (Ref. 43912). Pareutropius mandevillei closely resembles P. debauwi, both species being rather small and having a similar colour pattern; as most striking differences can be mentioned: the presence of two pairs of mandibular barbels in P. mandevillei (only one pair in P. debauwi), the longer barbels in P. mandevillei, the higher number of gill rakers on the lower part of the anterior arch in P. mandevillei (7-9 versus 5-7 in P. debauwi), the lower number of non-fused vertebrae (37-39 versus 39-41 in P. debauwi), and (probably) the presence of a posttemporal bone in P. mandevillei (which seems absent in P. debauwi)(Ref. 43912).

Coloration: dark mid-dorsal line continuing on upper half of caudal fin, somewhat bent downward near posterior border of caudal; dark lateral streak continues straight over caudal peduncle; dark spot above pectoral fin where swim-bladder lies close below skin; faint dark line above anal fin base; ventral side and other fins uncoloured (Ref. 43912).