A sound systematic framework is the vital first step into documenting and protecting biodiversity, especially in rapidly degrading aquatic environments that harbour high levels of cryptic species. Taxonomic programs to distinguish and describe species are essential for research, legislation and management. Without them confused identity, confounded ecological data, and unrealised extinction reign supreme. Rainbowfishes (family Melanotaeniidae) are brightly coloured small fishes common in fresh waters of the New Guinea-Australia region. They are a common and significant component of freshwater ecosystems, have cultural importance, and are popular in the aquarium trade. The number of described species in the group has increased rapidly in the last decade, largely attributable to the use of genetic techniques. All of the recently described species however, are from New Guinea. This study aims to improve biodiversity knowledge by undertaking taxonomic reviews of Australian rainbowfishes using museum material guided by the results of genetic data. Progress to date highlights that Australian rainbowfishes as a group are rich with narrow range endemics that are vulnerable to habitat modification and climate change. Showcasing the recently described Daintree Rainbowfish we review a modern combined lines of evidence approach to taxonomy that strives to inform stakeholders and conservation efforts.