Hemiodus

Hemiodus is a genus of halftooths from South America with the greatest species richness in the Amazon Basin, but also found in the Orinoco, Essequibo, Paraná–Paraguay and Parnaíba River basins. Depending on the species involved, these elongate fish reach a length of 7 - 30 cm.

Species
There are currently 21 recognized species in this genus:
 * Hemiodus amazonum (Humboldt, 1821)
 * Hemiodus argenteus Pellegrin, 1909
 * Hemiodus atranalis (Fowler, 1940)
 * Hemiodus goeldii Steindachner, 1908
 * Hemiodus gracilis Günther, 1864
 * Hemiodus huraulti (Géry, 1964)
 * Hemiodus immaculatus Kner, 1858
 * Hemiodus iratapuru Langeani & C. L. R. Moreira, 2013
 * Hemiodus jatuarana Langeani, 2004
 * Hemiodus langeanii Beltrão & Zuanon, 2012
 * Hemiodus microlepis Kner, 1858
 * Hemiodus orthonops C. H. Eigenmann & C. H. Kennedy, 1903
 * Hemiodus parnaguae C. H. Eigenmann & Henn, 1916
 * Hemiodus quadrimaculatus Pellegrin, 1909 (Barred hemiodus)
 * Hemiodus semitaeniatus Kner, 1858 (Halfline hemiodus)
 * Hemiodus sterni (Géry, 1964)
 * Hemiodus ternetzi G. S. Myers, 1927
 * Hemiodus thayeria J. E. Böhlke, 1955
 * Hemiodus tocantinensis Langeani, 1999
 * Hemiodus unimaculatus (Bloch, 1794)
 * Hemiodus vorderwinkleri (Géry, 1964)