The Aru Archipelago is a relict of the former land bridge connecting Australia and New Guinea and its freshwater Melanotaenia strongly reflect this past connection.Sea level changes over the past 2-3 million years have apparently provided sufficient isolation for the radiation of a mini species flock consisting of at least seven species. Melanotaenia patoti and M. senckenbergianus were described from the islands by Weber in the early 1900s, but subsequently considered as junior synonyms of the New Guinea mainland species M. rubrostriata and M. goldiei respectively. Recent collections by the authors facilitated a reassessment of their status based on morphological and genetic investigations,
consequently both are here recognised as valid and redescriptions are provided. In addition, the current study reveals the existence of five new taxa described herein.