{{Short description|Genus of fishes}} {{Automatic_taxobox | fossil_range = {{fossil range|Middle Miocene|present}} | image = Hemiodus quadrimaculatus Armbruster.jpg | image_caption = ''Hemiodus quadrimaculatus'' | taxon = Hemiodus | authority = J. P. Müller, 1842<ref name = "Cof family">{{Cof family|family=Hemiodontidae|access-date=22 July 2025}}</ref> | type_species = Hemiodus crenidens | type_species_authority = Müller, 1842 | synonyms = {{Genus list | Anisitsia | C. H. Eigenmann & C. H. Kennedy, 1903 | Hemiodopsis | Fowler, 1906 | Pterohemiodus | Fowler, 1940 }} | synonyms_ref = <ref name = "Cof family"/> }} thumb|''Hemiodus gracilis'' '''''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 {{convert|7|-|30|cm|in|abbr=on|0}}.<ref name=Beltrao2012>{{cite journal |author=Beltrão, H. |name-list-style=& |author2=Zuanon, J. |year=2012 |doi=10.1590/S1679-62252012000200004 |title=''Hemiodus langeanii'' (Characiformes: Hemiodontidae), a new species from rio Amana, rio Maués-Açú drainage, Amazon basin, Brazil |journal=Neotropical Ichthyology |volume=10 |issue=2 |pages=255-262}}</ref>
Fossil remains are known from the Middle Miocene-aged Pebas Formation of Peru.<ref>{{Cite journal |last1=Carrillo-Briceño |first1=Jorge D. |last2=Aguilera |first2=Orangel A. |last3=Benites-Palomino |first3=Aldo |last4=Hsiou |first4=Annie S. |last5=Birindelli |first5=José L. O. |last6=Adnet |first6=Sylvain |last7=Cadena |first7=Edwin-Alberto |last8=Scheyer |first8=Torsten M. |date=2021-12-20 |title=A historical vertebrate collection from the Middle Miocene of the Peruvian Amazon |journal=Swiss Journal of Palaeontology |language=en |volume=140 |issue=1 |pages=26 |doi=10.1186/s13358-021-00239-7 |doi-access=free |bibcode=2021SwJP..140...26C |issn=1664-2384}}</ref>
==Species== Hemiodus has the following species classified within it:<ref name = "Cof genus">{{Cof genus|genus=Hemiodus|access-date=22 July 2025}}</ref> * ''Hemiodus amazonum'' <small>(Humboldt, 1821)</small> * ''Hemiodus argenteus'' <small>Pellegrin, 1909</small> * ''Hemiodus atranalis'' <small>(Fowler, 1940)</small> * ''Hemiodus bimaculatus'' <small>Nogueira, Langeani & Netto‐Ferreira, 2019</small> * ''Hemiodus goeldii'' <small>Steindachner, 1908</small> * ''Hemiodus gracilis'' <small>Günther, 1864</small> * ''Hemiodus huraulti'' <small>(Géry, 1964)</small> * ''Hemiodus immaculatus'' <small>Kner, 1858</small> * ''Hemiodus iratapuru'' <small>Langeani & C. L. R. Moreira, 2013</small> * ''Hemiodus jatuarana'' <small>Langeani, 2004</small> * ''Hemiodus langeanii'' <small>Beltrão & Zuanon, 2012</small> * ''Hemiodus microlepis'' <small>Kner, 1858</small> * ''Hemiodus ocellatus'' <small>(Vari, 1982)</small> * ''Hemiodus orthonops'' <small>C. H. Eigenmann & C. H. Kennedy, 1903</small> * ''Hemiodus parnaguae'' <small>C. H. Eigenmann & Henn, 1916</small> * ''Hemiodus quadrimaculatus'' <small>Pellegrin, 1909</small> (Barred hemiodus) * ''Hemiodus semitaeniatus'' <small>Kner, 1858</small> (Halfline hemiodus) * ''Hemiodus sterni'' <small>(Géry, 1964)</small> * ''Hemiodus ternetzi'' <small>G. S. Myers, 1927</small> * ''Hemiodus thayeria'' <small>J. E. Böhlke, 1955</small> * ''Hemiodus tocantinensis'' <small>Langeani, 1999</small> * ''Hemiodus tucupi'' <small>Silva, Nogueira, Netto-Ferreira, Akama & Dutra, 2020</small> * ''Hemiodus unimaculatus'' <small>(Bloch, 1794)</small> * ''Hemiodus vorderwinkleri'' <small>(Géry, 1964)</small>
==References== {{Reflist}}
{{Taxonbar|from=Q5711870}}
Category:Hemiodontidae Category:Characiformes genera Category:Taxa named by Johannes Peter Müller Category:Fish of South America
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