Erythrinus erythrinus
Erythrinus erythrinus, the red wolf fish, is a relatively small species of trahira (family Erythrinidae) from freshwater habitats in South America. Range and habitat. "E. erythrinus" is a South American freshwater fish that is native to the Amazon and Orinoco basins, as well as rivers in the Guianas. The species is also reported as native to the Paraná—Paraguay basin, including the Pantanal, 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. "E. erythrinus" can reach a maximum standard length of , although other reports suggest it can reach about . It feeds primarily on small fish, insects, and benthic crustaceans. Juveniles are aggressive mimics of female aplocheilid killifish, notably "Laimosemion agilae", and they use this to catch male killifish that seek a mate. "E. erythrinus" is not of major interest to fisheries, but is sometimes used as a bait fish and seen in the aquarium fish trade. Taxonomy. It was described by Marcus Elieser Bloch and Johann Gottlob Schneider in 1801 , originally under the lizardfish genus "Synodus". The species was first placed in "Erythrinus" in 1854 by Gray (under the name "Erythrinus salmoneus", a junior synonym of "Erythrinus erythrinus"), and this treatment has been recognized by recent authorities such as Osvaldo Takeshi Oyakawa in 2003.