This species is distinguished from all its congeners in the gymnogenys group by having 23-25 E1 scales and the absence in adult males of a well-developed adipose hump. It is most easily distinguished from all species in the G. rhabdotus group (with terrapurpura, meridionalis, setequedas, che) by the pigmentation of the dorsal fin, where the spiny section of the dorsal fin lacks any markings (vs. various types of markings) and the soft section has long and thin whitish light blue lines parallel to rays (vs. wide stripes rhabdotus, a combination of roundish spots at the base and stripes of various length and width distally meridionalis, terrapurpura, setequedas, che; the anal fin also has long and thin whitish light blue lines parallel to rays (vs. spotted in terrapurpura and a combination of roundish spots at the base and stripes of various length and width distally in rhabdotus, meridionalis, setequedas, che, however, in setequedas only the posterior half of the anal fin has markings, while the anterior half has none. Within the G. setequedas group, G. taroba differs by having opalescent lines on posterior part of body and on caudal peduncle narrow, starting behind the midlateral blotch and are not found on the dorsum above the upper lateral line (vs. wide, beginning in front of the midlateral blotch and are found on the dorsum in setequedas, che); the midlateral blotch usually conspicuous and dominant, as in che (vs. inconspicuous in setequedas); opalescent markings on head large and dominant, present on opercular series, as in che (vs. small and inconspicuous, usually absent from opercular series in setequedas); body scales or their centers are grey, as in setequedas (vs. scale centers on at least the posterior part of body and caudal peduncle distinctly reddish-brown in che); the caudal fin with best developed white longitudinal lines and most pronounced difference between a yellow to orange central portion of the fin and red dorsal and ventral margins; it differs further from setequedas by having a longer snout, 44.4-53.7 %HL (vs. 30.8-44.7) and from che by having a deeper body, 40.2-46.1 % of SL (vs. 37.3-40.7) (Ref. 123557).