The goal of this research project is to produce a revised classification and analysis of geographic and taxonomic diversity of the Andean catfishes of the family Astroblepidae. Astroblepids are one of very few native groups of Andean fishes. The 54 species recognized to date are distributed in moderate to high elevation streams of the tropical Andes from Panama to Bolivia and occur in both the western Pacific and eastern Amazonian slope drainage systems. Because they occur in headwater streams, astroblepids are important indicators of the status of the diverse and economically important lowland rivers, yet our knowledge of their diversity, ecology, and distribution is rudimentary. This project will analyze all existing museum specimens and document astroblepid and Andean fish diversity at three high priority regions of South America. The research will produce a comprehensive synthesis of astroblepid taxonomy and biodiversity, new species descriptions, identification tools, and database of Andean fishes. The tropical Andes are the richest of the world's hotspots for biological diversity and home to thousands of plants and animals that are found nowhere else. The Andean fish fauna is poorly known and locally endangered by habitat alteration. This project will contribute important new information on the diversity and distribution of Andean fishes in broader efforts to understand the processes responsible for producing the highly diverse Andean biota and the assessment of priority areas for conservation in the Neotropics.