Bryconamericus caldasi can be distinguished from most congeners by the following characters: sides of the body with a dark lateral stripe overlaid by a peduncular spot and reticulated pattern (vs. peduncular spot and other body pigments not superimposed over a dark lateral stripe, except in B. oroensis which has a dark lateral stripe on body from posterior edge of opercle to base of caudal fin); 15-17 predorsal scales (vs. 9-14, except B. andresoi with 13-15, B. galvisi with 12-17, B. huilae with 14-19, B. plutarcoi and B. foncensis with 11-16); and a wide anterior maxilla tooth, at least twice as wide as the posterior tooth, both of which are pen¬tacuspid (vs. maxilla teeth of same size). It differs from B. oroensis by: pectoral-fin length (16.4-22.3% SL vs. 32.0-39.3% SL), pelvic-fin length (10.7-16.8% SL vs. 22.0-25.9% SL), caudal peduncle depth (9.3-14.9% SL vs. 16.7-23.8% SL), dorsal-anal fin distance (24.4-36.0% SL vs. 10.8-13.0% SL), dorsal-pectoral distance (34.4-45.6% SL vs.9.4-13.5% SL), anal-fin length (9.4-18.3% SL vs. 23.4-27.8% SL), length of maxilla (35.8-48.9% HL vs. 22.3-36.2% HL), and 4-5 scale rows between pelvic-fin and lateral lines (vs. 6-8). It can be diagnosed from the sympatric B. caucanus by having 15-17 predorsal median scales (vs.12-13), pectoral-fins not reaching or just reaching pelvic-fin insertions (vs. pectoral fins reaching poste¬rior to pelvic-fin insertions), convex predorsal profile (vs. oblique), small scales arranged in two or more rows at caudal-fin base (vs. large scales in just one row), and dorsal-fin origin position at vertical through posterior tip of pelvic-fin (vs. at a vertical anterior to pelvic-fin tip) (Ref. 106071).