A new Hyphessobrycon (Characiformes: Acestrorhamphidae) from the rio Mamuru basin, Amazonas State, Brazil

Abstract A new species of Hyphessobrycon from the rio Mamuru basin, Pará State, Brazil, is described. The new species is similar to two congeners, Hyphessobrycon hildae and Hy. taguae, and to a non-congener, Hemigrammus bellottii, by the presence of a conspicuous, vertically-elongated humeral blotch and the lack of other conspicuous dark color markings on body and fins, and by the presence, in life, of a bicolor longitudinal pattern dorsal to the longitudinal dark stripe composed by a dorsal thin red stripe and a ventral thin iridescent stripe. It differs from the abovementioned species by the shape of the humeral blotch. DNA barcoding methodology also distinguished the new species from He. bellottii sampled populations by 14.97 to 16.8% genetic distance in the cytochrome c oxidase I gene, and indicate the species as part of the subfamily Hyphessobryconinae and sister species of Hyphessobrycon montagi with genetic distance of 9.33%. Comments on the taxonomic status of Hy. hildae and Hy. taguae are made.