Revisiting Hypostomus khimaera (Siluriformes: Loricariidae): the identity of a morphologically variable species

This dataset contains the digitized treatments in Plazi based on the original journal article Carvalho, Vandergleison de, Müller, Victória Joana da Silva, Ferreira, Daniela Cristina, Zawadzki, Cláudio Henrique, Tencatt, Luiz Fernando Caserta (2024): Revisiting Hypostomus khimaera (Siluriformes: Loricariidae): the identity of a morphologically variable species. Neotropical Ichthyology 22 (3): e 240057, DOI: 10.1590/1982-0224-2024-0057, URL: doi.org/10.1590/1982-0224-2024-0057 Hypostomus khimaera, described from the upper rio Paraguai basin in Brazil, was reported to present some morphological variations in its original description, which allied to its relatively wide geographical distribution reinforced the need for a new assessment of its taxonomic status.

Here, we analyzed a new robust set of material, composed by 636 specimens from several localities within the upper rio Paraguai basin, besides the material listed in the original description. From this, it was possible to better understand the limits of the species providing a more accurate diagnosis and a redescription for H. khimaera, which also brought some light to the limits of the H. cochliodon group itself. The species can be distinguished from its congeners by having the following features: (I) absence of a notch between the metapterygoid and hyomandibula, (II) acutely angled dentaries, with up to about 90°, (III) teeth with medial cusp ranging from villiform to shovel-shaped, (IV) opercle completely surrounded by a thick layer of skin, (V) a longitudinal dark stripe along middle portion of flanks, which is variably diffuse, and (VI) dark spots on at least one part of the body.