Trophic and reproductive ecology of Argopleura magdalenensis (Pisces: Characidae) in the upper basin of the Cauca and Magdalena rivers, Colombia. Trophic and reproductive ecology was studied in the characid fish Argopleura magdalenensis, collected in the high watersheds of the Cauca and Magdalena rivers, Colombia. A. magdalenensis is insectivorous and algivorous. It was observed that the fish reproduced in the early wet season and is migratory. The male to female ratio was 2.2:1. The fecundity was low (288 oocytes) and the eggs were small (0.66 mm). Physical and chemical variables of the species habitat were measured