E. erythrinus is a South American
freshwater fish that is native to the
Amazon and
Orinoco basins, as well as rivers in the
Guianas. but the population in the lower Paraná basin and
Iguazu basin may be an
undescribed species.
E. erythrinus has been
introduced to the upper Paraná basin where not native. It mainly lives in creeks and marshes where the water has a
pH of 5.6–7.8. ==Appearance and behavior==