The Amblyopsidae are a fish family commonly referred to as cavefish, blindfish, or swampfish. They are small freshwater fish found in the dark environments of swamps, caves, and deep lakes in the eastern half of the United States. Like other troglobites, amblyopsids exhibit adaptations to these dark environments, including the lack of functional eyes and, in some species, the absence of pigmentation. About 170 species of cavefishes are known, but only six of these are in the family Amblyopsidae.