Variation in external morphology and coloration of H. acuen: a, b LBP 16279, 26.86 mm SL, affluent of rio Culuene, municipality of Gaúcha do Norte c, d MZUSP 115350, 25.9 mm SL, holotype, affluent of rio Toguro, municipality of Querência e (f) LBP16275, 21.67 mm SL, affluent of rio Feio, municipality of Querência.

 
 
  Part of: da Costa e Silva G, Roxo F, Oliveira C (2014) Hisonotus acuen, a new and phenotypically variable cascudinho (Siluriformes, Loricariidae, Hypoptopomatinae) from the upper rio Xingu basin, Brazil. ZooKeys 442: 105-125. https://doi.org/10.3897/zookeys.442.7870