Mylesinus

{{Short description|Genus of fishes}}

{{Automatic taxobox

| image =

| image_caption =

| taxon = Mylesinus

| authority = Valenciennes, 1850

| type_species = Mylesinus schomburgkii

| type_species_authority = Valenciennes, 1850

}}

Mylesinus is a genus of serrasalmids from South America, where found in the eastern Amazon, Essequibo and Orinoco basins. They are rheophilic, typically found at rapids and mainly feed on Podostemaceae plants.{{cite book |editor=J.E.P. Cyrino |title=Feeding and Digestive Functions in Fishes|page=28|year=2008|isbn=978-1-4398-4269-0}}{{cite journal |author1=O.B. Vitorino Júnior |author2=C.S. Agostinho |author3=F.M. Pelicice|title=Ecology of Mylesinus paucisquamatus Jégu & Santos, 1988, an endangered fish species from the rio Tocantins basin|journal=Neotrop. Ichthyol.|volume=14|issue=2|year=2016|doi=10.1590/1982-0224-20150124|doi-access=free|s2cid=56155368 |url=http://pdfs.semanticscholar.org/3d7e/8e7e93ddc3de12d120b7860d832c819f4c94.pdf}} Because of their habitat preference, they are threatened by the building of dams. They reach up to {{convert|35|cm|ft|abbr=on}} in standard length,{{FishBase genus | genus = Mylesinus| month = April | year = 2013}} and the adult males have a double-lobed anal fin and several filamentous extensions on the dorsal fin.{{cite book |editor1=van der Sleen, P. |editor2=J.S. Albert | year=2017 | title=Field Guide to the Fishes of the Amazon, Orinoco, and Guianas | publisher=Princeton University Press | page=184 | isbn=978-0691170749 }}