Adontosternarchus

{{Short description|Genus of fishes}}

{{Automatic Taxobox

| image = Adontosternarchus balaenops.jpg

| image_caption = Adontosternarchus clarkae

| taxon = Adontosternarchus

| authority = M. M. Ellis, 1912{{Cof family|family=Apteronotidae|access-date=23 May 2025}}

| type_species = Sternarchus sachsi

| type_species_authority = Peters, 1877

}}

Adontosternarchus is a genus of ghost knifefishes found in Amazon and Orinoco river basins in tropical South America. They have blunt snouts, a dark-spotted or -mottled pattern on a pale background (however, spotting/mottling can be so dense that individuals appear almost all dark) and reach up to {{convert|18.5-32.2|cm|in|abbr=on}} in total length.{{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=325 | isbn=978-0691170749 }}{{FishBase genus | genus = Adontosternarchus| month = August | year = 2017}} They feed on zooplankton and can be found quite deep, with A. devenanzii recorded down to {{convert|84|m|ft|abbr=on}}.