Diagnosed from other species of the genus Tyttocharax by the presence of bony hooks on the pectoral and caudal-fin rays (vs. absence). Differs from Tyttocharax madeirae and Tyttocharax cochui by the absence of adipose fin (vs. presence), in having larger bony hooks on the anal fin than on the rays of the pelvic fins (vs. bony hooks of the same size on the rays of those fins). Can be separated from Tyttocharax cochui in having i,5-6 pectoral-fin rays (vs. i,7); from Tyttocharax tambopatensis by absence of a sexually dimorphic color pattern in life (vs. presence of sexually dimorphic color pattern,
males have bright orange abdomens), by having 4 scales rows between anal-fin origin and lateral line (vs. 6), by the 4 scale rows between pelvic-fin and lateral line (vs. 6), by the number of 5-6 branched pectoral-fin rays (vs. 7); by iii unbranched dorsal-fin rays (vs. ii) and distance between the dorsal and anal-fin origins, 22.3% to 32.2% SL (vs. 38.0-41.0% SL) (Ref. 91745).
Description: dorsal-fin rays ii,5-7,i; anal-fin rays ii,13-18,i; pectoral-fin rays i,5-6,i; pelvic-fin rays i,3-6,i (Ref. 91745).