Erythrinus erythrinus, the red wolf fish, is a relatively small species of trahira (family Erythrinidae) from freshwater habitats in South America.

[2] E. erythrinus is a South American freshwater fish that is native to the Amazon and Orinoco basins, as well as rivers in the Guianas.

[5] E. erythrinus has been introduced to the upper Paraná basin where not native.

[2] It feeds primarily on small fish, insects, and benthic crustaceans.

[2] It was described by Marcus Elieser Bloch and Johann Gottlob Schneider in 1801,[9] originally under the lizardfish genus Synodus.