Pseudanos is a genus of headstanders in the family Anostomidae, native to blackwater and clearwater rivers of the Amazon and Orinoco basins. The atlas covers 5 species ranging from roughly 5–8.5 in, with records from Brazil, Venezuela, Guyana, Argentina, Bolivia, Colombia, Ecuador, and Peru. Like other anostomids, Pseudanos species have elongate, torpedo-shaped bodies and a terminal or slightly upturned mouth, and they are named for the distinctive oblique, head-down posture many headstanders adopt while grazing algae, biofilm, and detritus from submerged wood, leaf litter, and rock surfaces.
Species such as Pseudanos trimaculatus (threespot headstander), P. varii (redfin headstander), and P. gracilis (slender headstander) turn up occasionally in the specialist aquarium trade, where anostomids are valued as peaceful, actively grazing schooling fish for larger planted or driftwood-furnished tanks, though they remain far less commonly kept than more famous headstanders in other genera. Pseudanos irinae and P. winterbottomi are known mainly from scientific collections rather than the hobby. With three of the atlas's five species rated Least Concern and two not yet evaluated, the genus does not currently read as a conservation priority.