Diagnosis: The body of Heteromormyrus pauciradiatus is shorter and deeper and the head is deeper than in other Heteromormyrus species; body depth 25-31% of standard length, head depth 84-97% of head length; predorsal distance is 66-70% of standard length, more than in other Heteromormyrus species; the caudal peduncle is deeper than in other Heteromormyrus species, caudal peduncle depth 46-55% of caudal peduncle length; the eye is small, 12-15% of head length (Ref. 128501).

Description: Dorsal-fin rays 18, dorsal fin originating a little posterior to origin of anal fin; anal-fin rays 23; pectoral fin shorter than head length, hardly reaching base of pelvic fin; caudal fin with rounded lobes (Ref. 1878). Scales in lateral line 70, circumpeduncular scales 20 (Ref. 1878).