This species can be distinguished from its congeners (except A. pardalis and A. ucayalensis) by having an upper jaw that overhangs the lower jaw by a distance greater than the horizontal eye diameter (vs. less than the horizontal eye diameter). It is further distinguished by the following set of characters: reduced and ossified gas bladder (vs. large, non-ossified gas bladder) and by having epaxial musculature that covers the tympanic region (vs.tympanic region translucent, not concealed by epaxial musculature) in A. pardalis; robust pectoral spine, rigid and sharp (vs. pectoral spine slender, becoming progressively segmented in individuals larger than about 100 mm SL) and 45 vertebrae (vs. 53-55) in A. ucayalensis; anal-fin rays 37-46, mode 42 (vs. 32–38, mode 34-35) in A. lineatus; deeply forked caudal fin (vs. caudal fin strongly emarginate to truncate in A. inermis, A. magoi, A. polystictus and A. vittatus); more gill rakers on the first branchial arch 15-20, mode=18 (vs. 13-16, mode=14) and by usually having a dark band on the distal margin of the caudal-fin rays (vs. distal margin of caudal-fin rays hyaline) in A. apiaka (Ref. 124585).