Anostomus ternetzi, the red mouth headstander, is a species of freshwater ray-finned fish belonging to the family Anostomidae, the toothed headstanders.
The fish is named in honor of ichthyologist and naturalist (1870âÂÂ1928), who collected the type specimen.
It can grow to total length.
Anostomus ternetzi is widespread in South America: it is found in the Orinoco, Araguaia and Amazon River basins (Brazil, Colombia, and Venezuela) as well as in coastal rivers of Guianas. It occurs in both black and clear water rivers.