The Neotropics contain the most biologically diverse freshwater ecosystems on Earth and millions of people depend on their services, including clean water, fisheries and recreation. Aquatic biodiversity conservation in this region is hindered by many major knowledge gaps. At the most basic level, hundreds of Neotropical fish species remain undescribed and few guides exist to confidently identify named species. We also have little knowledge of the range boundaries or distributions of most fish species, let alone how they interact to contribute to ecosystem function. Neotropical rivers have historically received less conservation and research attention than forests that surround them, yet they are being rapidly degraded by combinations of threats including hydroelectric dams, gold mining, overfishing, deforestation, and urban and agricultural pollution. My research seeks to inventory aquatic biodiversity, discover and describe new species, create clear, concise species identification guides, and map ecological interrelationships – particularly among species that serve as the foundation of Neotropical river food webs. I list below a subset of recent relevant publications.