Acrobrycon starnesi is distinguished from A. ipanquianus by having the following characters: 61-66 perforated lateral-line scales (vs. 51 to 60); 22-26 horizontal scales rows around the caudal peduncle (vs. 19-21); body depth at the dorsal-fin origin 25.8-31.0% of SL (vs. 49.0-51.2%SL); horizontal diameter of the eye 30.4-36.5% HL (vs. 20.2-29.8% HL); and interorbital width 24.6-28.1% of HL (vs. 29.1-40.2% HL). It differs from A. ortii by having 22-26 branched anal-fin rays (vs. 19-21), 61-66 perforated lateral-line scales (vs. 53-58), 22-26 horizontal scales rows around the caudal peduncle (vs. 19-20), body depth at the dorsal-fin origin relative to the least interobital width 70-80% (vs. 90-120%), horizontal eye diameter relative to the least interorbital width 70-80% (vs. 90-110%), and body depth at dorsal-fin origin relative to the anal fin base length 100-120% (vs. 70-90%) (Ref. 94771).

Description: Anal-fin rays iv-v,22-26; pectoral-fin rays ii-iii,9-11 (Ref. 94771).