Chaetostoma bifurcum is distinguished from all congeners along along the Pacific Coast of South America except C. palmeri and C. paucispinis by having only 1 or 2 evertible cheek odontodes (vs. 3-6); from C. niveum, C. palmeri, C. patiae, and C. paucispinis by having most frequently 4 branched rays on anal fin (vs. 5); from C. palmeri and C. paucispinis by having body with black, indistinct, vertically elongate, irregularly broken or complete bars K to O width of orbit in living adults (vs. body uniform or with transverse cross-bars wider than two times orbit centered on dorsal midline); and from C. paucispinis by having 8 branched rays on dorsal fin (vs. 9) (Ref. 104727).

Description: Dorsal-fin branched rays 8; anal-fin branched rays 4-5; pectoral-fin branched rays 6; pelvic-fin branched rays 5 (Ref. 104727).