Pseudocorynopoma is a genus of characins in family Characidae, native to the La Plata basin of southeastern South America - the lowland rivers, streams, and lagoons of Argentina, Brazil, and Uruguay. The atlas's three species are modest fish, 2.5 in, sharing the deep-bodied, laterally compressed build and active, schooling habit typical of many South American tetras. They favor slow-flowing or still, vegetated waters rather than fast current, a habitat pattern common across the genus.
The dragon fin tetra, P. doriae, is the genus's aquarium star and the species most hobbyists will recognize: mature males develop a striking iridescent sheen and dramatically elongated, sail-like dorsal and anal fins used in display, giving the species its common name. It is an easy, peaceful community fish and a long-standing favorite among tetra keepers for that dimorphism alone. P. heterandria and P. stanleyi are far less familiar in the trade. Conservation status leans reassuring, with two of the three atlas species rated Least Concern and one not yet evaluated.