A taxonomic review of Spectracanthicus Nijssen & Isbrücker, including Oligancistrus Rapp Py-Daniel, following a phylogenetic study, is presented. Additionally to S. punctatissimus (Steindachner) and S. murinus Nijssen & Isbrücker, three new species are recognized based on the examination of 159 specimens: S. immaculatus n. sp. from rio Tapajós basin, differs from its congeners by its color pattern consisting of a dark gray body, with no dots or spots, and by having very slender teeth; Spectracanthicus tocantinensis n. sp., from the rio Tocantins drainage is distinguished by the color pattern consisting of dark brown or black body with small, yellowish dots (except in S. punctatissimus), presence of thick teeth, infraorbital 4 forming most of the posterior edge of the orbit and the large basipterigium fenestrae; and Spectracanthicus zuanoni n. sp., from the rio Xingu basin is diagnosed by its color pattern consisting of large, white spots and by the larger orbital diameter. Other characters based on osteological features are also usefull to distinguish the species. A key to the species of the genus and a brief discussion of their threats and conservation are also provided. © 2014 Sociedade Brasileira de Ictiologia.
Chamon, C. C., & Py-Daniel, L. H. R. (2014). Taxonomic revision of Spectracanthicus Nijssen & Isbrücker (Loricariidae: Hypostominae: Ancistrini), with description of three new species. Neotropical Ichthyology, 12(1), 1–25. https://doi.org/10.1590/S1679-62252014000100001