Hyphessobrycon is a genus of freshwater fish in the family Characidae, a family that also contains Piranhas. This genus belongs to a group of fish widely known as tetras. They are distributed from southern Mexico to Río de la Plata in Argentina. Many species are native to South America and about half a dozen species come from Central America. Many tetra species are popular aquarium fish and some are bred in large numbers in captivity.
The name piorskii honors the ichthyologist Nivaldo Magalhães Piorski for his contributions to the ichthyologic knowledge of the Maranhão State.
For the experts: A new species of Hyphessobrycon is described for the upper Munim and Preguiças river basins, northeastern Brazil, supported by morphological and molecular species delimitation methods. This new species belongs to the Hyphessobrycon sensu stricto group, as it has the three main diagnostic character states of this assemblage: presence of a dark brown or black blotch on the dorsal fin, absence of a black midlateral stripe on its flank and the position of Weberian apparatus upward horizontal through dorsal margin of operculum. Our phylogenetic analysis also supported the allocation of the new species in this group; however, it was not possible to recover the species sister-group. Pristella maxillaris and Moenkhausia hemigrammoides were recovered as the sister-clade of the Hyphessobrycon sensu stricto group.