# Hydrolycus

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> Source revision: 1354662019
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{{Short description|Genus of fishes}}
{{Automatic taxobox 
| image = Hydrolycus scomberoides by OpenCage.jpg
| image_caption = ''[Hydrolycus scomberoides](/source/Hydrolycus_scomberoides)''
| taxon = Hydrolycus
| authority = ([J. P. Müller](/source/Johannes_Peter_M%C3%BCller) & [Troschel](/source/Franz_Hermann_Troschel), 1844)
| type_species = Hydrocyon scomberoides
| type_species_authority = [Cuvier](/source/Georges_Cuvier), 1819<ref name = "Cof family">{{Cof family|family=Cynodontidae|access-date=17 July 2025}}</ref>
}}

'''''Hydrolycus''''' is a [genus](/source/genus) of freshwater [ray-finned fishes](/source/Actinopterygii) belonging to the [family](/source/Family_(taxonomy)) [Cynodontidae](/source/Cynodontidae), the [dogtooth characin](/source/dogtooth_characin)s. These fishes are found in [tropical](/source/tropical) South America, where found in the [Amazon](/source/Amazon_basin) and [Orinoco](/source/Orinoco) basins, as well as rivers of the [Guianas](/source/Guianas).<ref name=fishbase>{{FishBase genus | genus = Hydrolycus| month = January | year = 2017}}</ref> The genus includes the largest dogtooth characins, reaching up to {{convert|1.17|m|ft|abbr=on}} in length.<ref name=fishbase/> They have long, pointed teeth (shorter and less extreme in ''H. wallacei'') used for spearing their prey, generally smaller fish.<ref name=Toledo1999>{{cite journal |author1=Toledo-Piza, M. |author2=N.A. Menezes |author3=G.M. Santos | year=1999 | title=Revision of the Neotropical fish genus Hydrolycus (Ostariophysi: Characiformes: Cynodontidae) with the description of two new species | journal=Ichthyol. Explor. Freshwaters | volume=10 | issue=3 | pages=255–280 }}</ref> In a study of the stomachs of 45 individuals, most were empty, but among the remaining the prey fish were 15–50% of the length ''Hydrolycus'' itself.<ref name=Goulding1980>{{cite book | author=Goulding, M  | year=1980 | title=The Fishes and the Forest: Explorations in Amazonian Natural History | publisher=University of California Press | pages=185–186 | isbn=0-520-04131-3 }}</ref>

In 1999 two new species were [described](/source/Species_description), the first in this genus in 158 years.<ref name=fishbase/><ref name=Toledo1999/>

==Species==
[[File:Hydrolycus armatus cropped.jpg|thumb|''[Hydrolycus armatus](/source/Hydrolycus_armatus)'']]

There are currently four described [species](/source/species).<ref name="Cof genus">{{Cof genus|genus=Hydrolycus|access-date=17 July 2025}}</ref>

* ''[Hydrolycus armatus](/source/Hydrolycus_armatus)'' <small>([Jardine](/source/Sir_William_Jardine%2C_7th_Baronet), 1841)</small> (Payara)
* ''[Hydrolycus scomberoides](/source/Hydrolycus_scomberoides)'' <small>([G. Cuvier](/source/Georges_Cuvier), 1819)</small> (Payara)
* ''[Hydrolycus tatauaia](/source/Hydrolycus_tatauaia)'' <small>[Toledo-Piza](/source/Species%3AM%C3%B4nica_de_Toledo-Piza_Ragazzo), [Menezes](/source/Species%3ANa%C3%A9rcio_Aquino_de_Menezes) & [dos Santos](/source/Geraldo_Mendes_dos_Santos), 1999</small>
* ''[Hydrolycus wallacei](/source/Hydrolycus_wallacei)'' <small>Toledo-Piza, Menezes & dos Santos, 1999</small>

==References==
{{Reflist}}

{{Taxonbar|from=Q5955132}}

Category:Cynodontidae
Category:Hydrolycus
Category:Taxa named by Johannes Peter Müller
Category:Taxa named by Franz Hermann Troschel
Category:Freshwater fish of South America

{{Characiformes-stub}}

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Adapted from the Wikipedia article [Hydrolycus](https://en.wikipedia.org/wiki/Hydrolycus) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Hydrolycus?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.