Anostomus ternetzi, the red mouth headstander, is a fish in the family Anostomidae.
The fish is named in honor of ichthyologist and naturalist Carl Ternetz (1870–1928), who collected the type specimen.[1]
It can grow to 12cm (05inches) 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.