A new Hemigrammus (Characiformes: Acestrorhamphidae) from the rio Cuiabazinho drainages, upper rio Paraguai basin

Abstract A new species of Hemigrammus is described from tributaries of the rio Cuiabazinho, upper rio Paraguai basin, Mato Grosso State, Brazil. It can be readily distinguished from all its congeners by a unique combination of characters, including a distinctive body coloration pattern without spots, the number of perforated lateral-line scales (12–15), the number of branched rays on anal fin (21–25), and the presence of small bony hooks at the tips of the lepidotrichia of the second to fourth branched rays of the pelvic fins, which are absent in the anal fin. We also provide a brief discussion on the recent taxonomic reconfiguration of Hemigrammus.