This is distinguished from all congeners in Central America by having 49 to 54 scales in the lateral line (vs. 43 to 48 in Brycon argenteus, 55 to 61 in B. guatemalensis, and more than 64 in B. behreae, B. chagrensis and B. striatulus) and anal fin notably longer than head, with 33 to 37 total rays (vs. an anal fin about equal to length of head, with 24 to 28 total rays in B. argenteus , B. obscurus, and B. petrosus, the last two species with 48 to 55 and 53 to 58 scales in the lateral line, respectively). This species can be further diagnosed from B. guatemalensis by the following combination of characters: 5 or 6 rows of scales between lateral line and pectoral fin base (vs. 7 or 8); 9 to 11 (generally 10) rows of scales between lateral line and dorsal fin base (vs. 10 to 12, generally 11); 5 to 7 (generally 6) rows of scales between lateral line and anal fin base (vs. 7 to 9, generally 8); and a elongated and shallow caudal peduncle, whose length is 1.78 to 2.35 times its depth (vs. a short and deep caudal peduncle, whose length is 1.25 to 1.61 times its depth) (Ref. 95069).