MegadontognathusMegadontognathus is a genus of ghost knifefishes found in river rapids in tropical South America. They are brown with a stubby snout and reach about in total length.SpeciesThere are currently two described species in this genus:Megadontognathus cuyuniense Mago-Leccia, 1994Megadontognathus kaitukaensis Campos-da-Paz, 1999