Key words: DNA barcoding, Fish taxonomy, Hypostominae, Neotropical fishes, rio Grande basin, Systematics.Abstract
In a recent expedition to the rio Grande basin, a tributary of the rio Parana in southern Brazil, individuals of the armored catfish genus Hypostomus with a peculiar and beautiful color pattern composed of pale vermiculations on the head and four to five horizontal stripes on the flanks was collected. Initially, the specimens were identified as a color morph of the pale-spotted H. margaritifer. However, when we compared their partial cytochrome C oxidase subunit I (COI) mitochondrial gene to sequences of some typically pale-spotted H. margaritifer, the striped specimens were genetically distinct. Further analysis of the striped individuals revealed that they are the poorly known but valid species Hypostomus variipictus, which was described by Ihering in 1911 from the rio Pardo, a tributary of the rio Grande, upper rio Paraná basin, in São Paulo State, Brazil. Since its descriptions, no robust taxonomic work has been published concerning this species. In this study, the newly sampled population was compared to the original description and to the holotype of H. variipictus, providing the foundation for a complete redescription, proper diagnosis, and first live color illustration and description of the previously hidden H. variipictus.