The global ornamental trade network has facilitated the large-scale import of non-native freshwater fish into Australia, providing benefits to society through fishkeeping and to the economy through a rapidly growing domestic industry. However, subsequent introduction and establishments of ornamental species into freshwater ecosystems marks ornamental trade as a fundamental and mounting threat to the unique native freshwater ichthyofauna of Australia. This is particularly heightened in tropical regions of northern Australia where ongoing invasions of freshwater ornamental fish are projected to increase substantially due to favourable climate bands. A largely understudied industry provides the backdrop for these ornamental invasions, with limited information available on the freshwater ornamental fish involved, including hazardous and imperilled species, and the extent of illegal and unregulated trade within Australia. These critical knowledge gaps inhibit the development of effective and proactive strategies necessary to manage biosecurity threats from the ornamental industry in Australia, leading to potential impacts for unique native freshwater ichthyofauna. The aim of my research was to quantify the freshwater ornamental fish industry within Australia, providing foundational knowledge on multiple facets of the supply chain including the trade of hazardous, illegal, and imperilled species within regulated and unregulated sectors. Additionally, my research aims to evaluate and develop proactive management strategies to mitigate biosecurity threats from freshwater ornamental fish in trade. [...]