The ram cichlid, Mikrogeophagus ramirezi, is a species of freshwater fish endemic to the Orinoco River basin, in the savannahs of Venezuela and Colombia in South America. The species has been examined in studies on fish behaviour and is a popular aquarium fish, traded under a variety of common names, including ram, blue ram, German blue ram, Asian ram, butterfly cichlid, Ramirez’s dwarf cichlid, dwarf butterfly cichlid and Ramirezi. The species is a member of the family Cichlidae and subfamily Geophaginae.
The natural habitat of M. ramirezi is warm (25.5-29.5 °C, 78-85 °F), acidic (pH 5.2-6.7) water courses in the llanos savannahs of Venezuela and Colombia. The water is generally slow-flowing, contains few dissolved minerals, and ranges in colour from clear to darkly stained with tannins. The species is typically found where cover in the form of aquatic or submersed vegetation is available.