Hemibrycon jelskii (Steindachner 1876)

This species is distinguished from its congeners, except H. helleri, by the size of humeral spot (over 7-9 vs. 3-6 horizontal series of scales); differs from H. helleri by the number of branched anal-fin rays (25-30 vs. 19-23), and by the number of scales along anal-fin base scale sheath (13-28 vs. 6-12); differs from H. divisorensis, by the absence of a wide black asymmetrical spot covering base of caudal-fin rays and black band in the lower half of the caudal peduncle (vs. presence), and by the number of scale rows above and below lateral line (7-9 and 5-7 vs. 6-7 and 4-5, respectively) (Ref. 85819).

Dorsal soft rays (total): 8; Analsoft rays: 25 - 30; Vertebrae: 38 - 40