Key to the species of Pseudanos (From Birindelli 2012)

1a. Relatively broad, dark midlateral stripe on body; midlateral blotches absent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pseudanos winterbottomi (Río Orinoco basin, Rio Tapajós basin; Fig. 7).

1b. Two to four midlateral dark blotches on body; no midlateral dark stripe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2a. Dark, narrow transversal bars present on dorsum; body depth at dorsal-fin origin 24.7–30.0, mean 26.7% of SL; cranial fontanel partially closed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pseudanos trimaculatus (Amazon basin, including lower Rio Negro and Rio Branco, Essequibo River basin, and Río Orinoco basin; Fig. 7).

2b. Dorsum lacking dark transversal bars; body depth at dorsal-fin origin 18.4–26.7, mean 22.2% of SL in P. varii, and 18.1–22.4, mean 19.5 of SL in P. gracilis; cranial fontanel opened along its entire length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3a. Body with dark spots on the center of each body scale, forming conspicuous, straight dark lines; three branchiostegal rays; angle of dorsal and ventralmost radii of body scales between 40° and 90° . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pseudanos varii sp.n. (Rio Negro basin, Río Casiquiare and Río Atabapo, upper Río Orinoco basin; Fig. 4).

3b. Body with dark pigmentation on upper and lower portion of scales forming faint, straight to wavy longitudinal lines, but lacking pigmentation on the center of body scales; four branchiostegal rays; angle of dorsal and ventralmost radii of body scales between 110° and 180° .... Pseudanos gracilis (central Amazon basin, including Rio Negro, Rio Branco, Rio Uatumã and Rio Madeira basins; Fig. 7).