I am a scientist interested in the conservation, diversity, and interrelationships of freshwater fishes, with a particular focus on the fishes of eastern North America and tropical South America. Freshwater ecosystems span <0.08% of Earth's surface, yet these habitats host nearly 60% of all described species. Unfortunately, freshwater species are going extinct several times faster than terrestrial or marine species due to environmental impacts that disproportionately affect streams, rivers and lakes. Still, thousands of freshwater species remain unrecognized or poorly known to science, with many of these concentrated in the tropics. My research strives to better delineate and identify species, understand how they feed and interact, and map where they are distributed in nature and the evolutionary tree of life. Natural history museums are the foundation for this research, and I help build these libraries of life through the collection of well-identified specimens, tissues, and photographs. To date, I have conducted over 20 expeditions to 11 countries in the Americas and Africa, yielding over 14,000 specimen lots and 7,500 tissues. This work regularly yields the discovery and description of new fish and invertebrate species, new insights into the ecology and evolution of threatened fish assemblages, and baseline data needed to guide conservation strategies for businesses, governments and NGOs.