Gymnogeophagus

Gymnogeophagus is a genus of cichlid fishes from South America, where they are known from various river basins (notably Rio de la Plata and Lagoa dos Patos–Mirim) in southern Brazil, Paraguay, Uruguay and northern Argentina. They are part of a group popularly known as eartheaters.

Species
There are currently 18 recognized extant species in this genus:


 * Gymnogeophagus australis (C. H. Eigenmann, 1907) (Uruguayan eartheater)
 * Gymnogeophagus balzanii (Perugia, 1891) (Argentine eartheater)
 * Gymnogeophagus caaguazuensis Staeck, 2006
 * Gymnogeophagus che Casciotta, S. E. Gómez & Toresanni, 2000
 * Gymnogeophagus constellatus L. R. Malabarba, M. C. Malabarba & R. E. dos Reis, 2015
 * Gymnogeophagus gymnogenys (R. F. Hensel, 1870) (Smooth-cheek eartheater)
 * Gymnogeophagus jaryi Alonso et al., 2019
 * Gymnogeophagus labiatus (R. F. Hensel, 1870) (Earth eater)
 * Gymnogeophagus lacustris R. E. dos Reis & L. R. Malabarba, 1988
 * Gymnogeophagus lipokarenos L. R. Malabarba, M. C. Malabarba & R. E. dos Reis, 2015
 * Gymnogeophagus mekinos L. R. Malabarba, M. C. Malabarba & R. E. dos Reis, 2015
 * Gymnogeophagus meridionalis R. E. dos Reis & L. R. Malabarba, 1988
 * Gymnogeophagus missioneiro L. R. Malabarba, M. C. Malabarba & R. E. dos Reis, 2015
 * Gymnogeophagus pseudolabiatus L. R. Malabarba, M. C. Malabarba & R. E. dos Reis, 2015
 * Gymnogeophagus rhabdotus (R. F. Hensel, 1870) (Stripe-fin eartheater)
 * Gymnogeophagus setequedas R. E. dos Reis, L. R. Malabarba & Pavanelli, 1992
 * Gymnogeophagus terrapurpura Loureiro, Zarucki, L. R. Malabarba & González-Bergonzoni, 2016
 * Gymnogeophagus tiraparae González-Bergonzoni, Loureiro & Oviedo, 2009

An extinct species Gymnogeophagus eocenicus lived during the Early Eocene of Argentina, around, representing one of the oldest known cichlids.