Hemiodus

Francisco Langeani, 2004, Hemiodus jatuarana, a new species of Hemiodontidae from the rio Trombetas, Amazon Basin, Brazil (Teleostei, Characiformes)., Zootaxa 546, pp. 1-6 : 1

[[ Genus Hemiodus ]]

Hemiodus Mueller , 1842, the largest genus in the Hemiodontidae, contains 18 species that occur in basins of Cis-Andean South America, including the Amazonas, Orinoco, Tocantins, costal rivers of the Guianas, some smaller independent drainages from the rio Araguari to the rio Paranaíba, and the Paraná-Paraguay basin (Langeani, 2003). Species of Hemiodus are clearly separated from all other members of the family by the presence of multicuspid teeth with an enlarged convex distal border (vs. teeth absent in Anodus ; unicuspid, pedicellated in Micromischodus ; tricuspid in Argonectes and Bivibranchia ). Hemiodus species also present a right angle depression on the ventromedial portion of the preopercle which receives the posteroventral portion of the hyomandibular (Langeani, 1998, 1999).