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 (3–12 in).^[2]

Hemiodus Temporal range: Middle Miocene–present PreꞒ Ꞓ O S D C P T J K Pg N
Hemiodus quadrimaculatus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Characiformes
Family:	Hemiodontidae
Genus:	Hemiodus J. P. Müller, 1842[1]
Type species
Hemiodus crenidens Müller, 1842
Synonyms[1]
Anisitsia C. H. Eigenmann & C. H. Kennedy, 1903 Hemiodopsis Fowler, 1906 Pterohemiodus Fowler, 1940

Hemiodus gracilis

Fossil remains are known from the Middle Miocene-aged Pebas Formation of Peru.^[3]

Species

Hemiodus has the following species classified within it:^[4]

• Hemiodus amazonum (Humboldt, 1821)
• Hemiodus argenteus Pellegrin, 1909
• Hemiodus atranalis (Fowler, 1940)
• Hemiodus bimaculatus Nogueira, Langeani & Netto‐Ferreira, 2019
• 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 ocellatus (Vari, 1982)
• 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 tucupi Silva, Nogueira, Netto-Ferreira, Akama & Dutra, 2020
• Hemiodus unimaculatus (Bloch, 1794)
• Hemiodus vorderwinkleri (Géry, 1964)