Australian rainbowfish of the genus Melanotaenia are freshwater fishes native to northern and eastern Australia, where they inhabit rivers, streams, billabongs, wetlands, and lakes, often in areas with moderate flow and aquatic vegetation. They are characterised by a laterally compressed body and typically display iridescent coloration that can include shades of blue, green, red, and yellow, with males developing more intense colours and deeper bodies than females as they mature. These fish are schooling and occupy midwater, feeding on small aquatic invertebrates, algae, and plant matter. Many species are adapted to seasonal environmental changes such as fluctuations in water level, temperature, and flow, and are commonly associated with clear to moderately turbid freshwater habitats.