Australoheros capixaba is distinguished from A. facetus, A. kaaygua, A. tembe, A. forquilha, A. guarani, A. minuano, A. scitulus, A. charrua and A. taura by having fewer caudal vertebrae (12 in A. capixaba vs. 13 – 15 in the other species). Australoheros capixaba differs from A. saquarema, A. muriae, A. robustus, A. barbosae, A. macacuensis, A. ipatinguensis, A. paraibae and A. ribeirae by having a longer caudal peduncle (9.6 – 11.4 % SL in A. capixaba vs. 5.1 – 9.2 % SL in the other species); from A. autrani, A. barbosae, A. ipatinguensis, A. muriae and A. saquarema by having fewer anal-fin rays (8 in A. capixaba vs. 9 – 10 in the other species); from A. macacuensis, A. macaensis, A. ribeirae and A. saquarema by having large red spots on the dorsal portion of the trunk (vs. absence); from A. autrani, A. macacuensis, A. macaensis and A. saquarema by having a reddish chest (vs. chest not reddish, i.e. a coloration similar to the entire trunk); from A. macaensis and A. saquarema by not having a detached snout, with a depression on the snout (vs. detached snout, with depression on head in specimens above 30.0 mm SL); from A. robustus by fewer dorsal-fin spines (15 – 16 vs. 17) and more dorsal-fin rays (10 – 11 vs. 8 – 9); from A. macacuensis by having both arms of trunk bar 7 with the same width (vs. postero-dorsal arm of trunk bar 7 wider than anterior one) and pelvic fins with green and yellow iridescence (vs. black or dark brown); and from A. paraibae by having a longer last anal-fin spine (last anal-fin spine length 14.0 – 17.2 % SL vs. 12.2 – 13.3 % SL) (Ref. 84134).