The Buenos Aires tetra derives its name from the capital city of Argentina. The city sits on the western shore of the Río de la Plata, located along the southeastern coastline of South America. Considered a river by some and a gulf by others, the Río de la Plata is formed by the joining of the Paraná and Uruguay Rivers, both of which are home to the Buenos Aires tetra. In the wild, they are additionally found in rivers, ponds, lakes, and streams. They are freshwater fish and do not do well in highly salty or polluted waters.