Highly troglomorphic catfish, genus Rhamdiopsis (Siluriformes: Heptapteridae), a relict from Campo Formoso karst area, northeastern Brazil (Photo: Dante Fenolio).

  Part of: Trajano E, Carvalho MR (2017) Towards a biologically meaningful classification of subterranean organisms: a critical analysis of the Schiner-Racovitza system from a historical perspective, difficulties of its application and implications for conservation. Subterranean Biology 22: 1-26. https://doi.org/10.3897/subtbiol.22.9759