A new cryptic species of Hyphessobrycon Durbin, 1908 (Characiformes, Characidae) from the Eastern Amazon, revealed by integrative taxonomy

Hyphessobrycon caru sp. nov. is described based on five different and independent methods of species delimitation, making the hypothesis of this new species supported by an integrative taxonomy perspective. This new species has a restricted distribution, occurring just in the upper Pindaré river drainage, Mearim river basin, Brazil. It is a member of the rosy tetra clade, which is characterized mainly by the presence of a dark brown or black blotch on dorsal fin and absence of a midlateral stripe on the body. Hyphessobrycon caru sp. nov. is distinguished from the members of this clade mainly by the shape of its humeral spot, possessing few irregular inconspicuous vertically arranged chromatophores in the humeral region, or sometimes a very thin and inconspicuous humeral spot, and other characters related to teeth count, and color pattern. The phylogenetic position of the new species within the rosy tetra clade was based on molecular phylogenetic analysis using sequences of the mitochondrial gene cytochrome oxidase subunit 1. In addition, a new clade (here termed Hyphessobrycon micropterus clade) within the rosy tetra clade is proposed based on molecular data, comprising H. caru sp. nov., H. micropterus, H. piorskii, and H. simulatus, and with H. caru sp. nov. and H. piorskii recovered as sister species. Our results suggest cryptic speciation in the rosy tetra clade and, more specifically, in the H. micropterus clade. We recommend the use of integrative taxonomy for future taxonomic revisions and species descriptions when dealing with species complexes and groups containing possible cryptic species